Game program, information processing system, information processing device, and game processing method

Abstract

To effectively reduce the number of apexes of a mesh of an object.SOLUTION: An information processing system simplifies a plurality of apexes to each of which at least one kind of material is set, which are apexes constituting a mesh defined in a virtual space, and draws a mesh based on the apexes in which simplification is reflected, on the basis of drawing settings based on a material of each apex. The simplification is achieved when a plurality of apexes of an apex group are replaced by one apex to which a total number of kinds of materials are set when a simplification condition at least including a fact that a total number of kinds of materials of each apex included in the apex group is a first number or less is satisfied for each of a plurality of apex groups including a plurality of adjacent apexes respectively.SELECTED DRAWING: Figure 19

Description

Technical Field

[0001] The present invention relates to a game program, an information processing system, an information processing apparatus, and a game processing method for generating an object in a virtual space.

Background Art

[0002] Conventionally, objects have been managed using voxel data, and a mesh of an object has been generated in a virtual space based on the voxel data (see, for example, Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desired to effectively reduce the number of vertices of a mesh of an object.

Means for Solving the Problems

[0005] To solve the above problems, the present invention employs the following configurations (1) to (11).

[0006] (1) An example of the present invention is a game program that causes a computer of an information processing apparatus to execute the following processing for a plurality of vertices that are vertices constituting a mesh defined in a virtual space and each have at least one type of material set thereon. ·For each of a plurality of vertex groups each including a plurality of adjacent vertices, when a simplification condition including at least that the total number of types of materials of each vertex included in the vertex group is equal to or less than a first number is satisfied, perform a simplification process of replacing the plurality of vertices of the vertex group with one vertex having the types of materials equal to the total number. ·A process of rendering a mesh based on the vertices with the simplification reflected thereon based on a rendering setting based on the material of each vertex.

[0007] According to the configuration of (1) above, the number of vertices of the mesh can be effectively reduced by simplification.

[0008] (2) In the configuration of (1) above, the game program may further cause the computer to execute the following process based on voxel data defined in the virtual space, the voxel data including, for each of a plurality of voxels, at least a density indicating the degree to which the space defined by the voxel is virtually occupied by the content, and a material indicating the type of the content, the material being settable up to a second number. ·For a portion where a voxel having a density of a setting indicating existence and a voxel having a density of a setting indicating non - existence are adjacent, set vertices at coordinates based on the positions and densities of a plurality of surrounding voxels, and for each of the vertices, determine the vertex by selecting, as the material of the vertex, up to a first number of materials among the materials included in the voxel data of the plurality of surrounding voxels. ·When generating a mesh in the virtual space, a process of performing simplification on the entire set of vertices determined based on the voxel data. ·A process of generating a mesh based on the vertices with the simplification reflected thereon.

[0009] According to the configuration of (2) above, it is possible to suppress an increase in the number of vertices of the mesh set using voxels.

[0010] (3) In the configuration of (2) above, the game program may further cause the computer to execute the following processing. ·Processing for performing an update in which at least one of density and material changes for at least any one of the voxels included in the voxel data based on game processing ·Processing for further setting and simplifying the coordinates of vertices for the vertices in the range including the location where the update was performed when the update is performed ·Processing for updating the mesh based on the vertices with the simplification reflected

[0011] According to the configuration of (3) above, the processing load due to simplification can be reduced.

[0012] (4) In the configuration of (3) above, the game program may cause the computer to execute the following processing. ·For each vertex, calculate the priority parameter for each material based on the voxel data of the voxel materials of a plurality of surrounding voxels, and based on the priority parameter, select the materials up to the first number with the highest priority and determine them as the material of the vertex ·For each polygon, select the materials up to the first number among the materials set for the vertices included in the polygon and determine them as the material of the polygon ·For each polygon, based on the materials of all the vertices constituting the polygon, if the number of materials is less than or equal to the first number, set the material as the material of the polygon ·For each polygon, based on the materials of all the vertices constituting the polygon, if the number of materials exceeds the first number, select the first number with the highest priority based on the priority parameter of each vertex and determine it as the material of the polygon

[0013] According to the configuration of (4) above, it is possible to reflect the material of the voxel in the material of the polygon while suppressing the number of types of the material of the polygon to the first number.

[0014] (5) In the configuration of the above (4), the game program may further cause the computer to perform rendering setting information including at least information on the texture set for the material, and based on the rendering setting information corresponding to each material set for each polygon included in the mesh, at the position of each vertex, at a blending rate corresponding to the priority parameter of the vertex, between the vertices, a plurality of textures are blended by interpolation blending rate obtained by interpolating the blending rate of each vertex, and the polygon may be rendered by mapping.

[0015] According to the configuration of the above (5), the appearance at the boundary of different materials in the mesh can be made more natural.

[0016] (6) In any of the configurations of the above (1) to (3), the game program may further cause the computer to execute the following processing. · For each polygon of the mesh, among the materials set for the vertices included in the polygon, select the materials up to the first number and determine them as the material of the polygon, thereby generating and updating the material of the polygon · Based on the coordinates of the vertices of the mesh and the texture corresponding to the material of the polygon, render the mesh

[0017] According to the configuration of the above (6), the materials up to the first number set for the simplified vertices can be reflected in the appearance of the mesh.

[0018] (7) In any of the configurations of the above (1) to (6), the simplification condition may further include that vertices where material reduction is performed to set the materials of the first number based on the materials exceeding the first number, or vertices simplified based on the vertices where the material reduction is performed, are not included in the vertex group.

[0019] According to the configuration of (7) above, it is possible to suppress an increase in the area of a polygon with an unnatural appearance.

[0020] (8) In any of the configurations from (1) to (7) above, the simplification condition may further include that the shape error between the mesh before simplification and the mesh after simplification is within a predetermined range.

[0021] According to the configuration of (8) above, it is possible to suppress a large change in the shape of the mesh due to simplification.

[0022] (9) In any of the configurations from (1) to (8) above, the first number and the second number may be 2.

[0023] According to the configuration of (9) above, information on two types of materials set for the voxels can be reflected in the materials of the vertices after simplification.

[0024] (10) In any of the configurations from (1) to (9) above, the game program may further cause the computer to determine a determination mesh corresponding to the voxel data and used for collision determination in the game process, based on at least the density included in the voxel data for the vertex coordinates of the determination mesh, and determine the material of the determination mesh based on at least the material included in the voxel data, and further generate or update it by performing simplification.

[0025] According to the configuration of (10) above, it is also possible to effectively reduce the number of vertices for the determination mesh.

[0026] (11) In the configuration of the above (10), the simplification condition may further include that the error in the shape between the mesh before simplification and the mesh after simplification is within a predetermined range. The simplification condition for the determination mesh may be such that the range including an error larger than the error in the mesh simplification condition is the predetermined range.

[0027] According to the configuration of the above (11), the number of vertices of the mesh for collision determination can be made smaller than the number of vertices of the mesh for display.

[0028] In addition, another example of the present invention may be an information processing apparatus or an information processing system that executes the processing in the above (1) to (11). Further, another example of the present invention may be a game processing method that causes an information processing system to execute the processing in the above (1) to (11).

Advantages of the Invention

[0029] According to the above game program, information processing system, information processing apparatus, or game processing method, the number of vertices of the mesh can be effectively reduced.

Brief Description of the Drawings

[0030]

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Embodiments for Carrying Out the Invention

[0031] [1. Configuration of the Game System] Hereinafter, a game system according to an example of the present embodiment will be described. An example of the game system 1 in the present embodiment includes a main body device (information processing device; functioning as a game device main body in the present embodiment) 2, a left controller 3, and a right controller 4. The left controller 3 and the right controller 4 are each detachable from the main body device 2. That is, the game system 1 can be used as a device in which the left controller 3 and the right controller 4 are each attached to the main body device 2 and integrated. Also, the game system 1 can be used with the main body device 2, the left controller 3, and the right controller 4 as separate entities (see Fig. 2). Hereinafter, the hardware configuration of the game system 1 of the present embodiment will be described, and then the control of the game system 1 of the present embodiment will be described.

[0032] FIG. 1 is a diagram showing an example of a state in which the left controller 3 and the right controller 4 are attached to the main body device 2. As shown in FIG. 1, the left controller 3 and the right controller 4 are respectively attached to and integrated with the main body device 2. The main body device 2 is a device that executes various processes (for example, game processing) in the game system 1. The main body device 2 includes a display 12. The left controller 3 and the right controller 4 are devices provided with an operation unit for the user to input.

[0033] FIG. 2 is a diagram showing an example of a state in which the left controller 3 and the right controller 4 are respectively removed from the main body device 2. As shown in FIGS. 1 and 2, the left controller 3 and the right controller 4 are detachable from the main body device 2. In the following, the left controller 3 and the right controller 4 may be collectively referred to as "controller".

[0034] FIG. 3 is a six-sided view showing an example of the main body device 2. As shown in FIG. 3, the main body device 2 includes a substantially plate-shaped housing 11. In the present embodiment, the main surface of the housing 11 (in other words, the front surface, that is, the surface on which the display 12 is provided) is generally rectangular.

[0035] Note that the shape and size of the housing 11 are arbitrary. As an example, the housing 11 may be of a portable size. Also, the main body device 2 alone or the integrated device in which the left controller 3 and the right controller 4 are attached to the main body device 2 may be a portable device. Also, the main body device 2 or the integrated device may be a handheld device. Also, the main body device 2 or the integrated device may be a portable device.

[0036] As shown in FIG. 3, the main body device 2 includes a display 12 provided on the main surface of the housing 11. The display 12 displays an image generated by the main body device 2. In the present embodiment, the display 12 is a liquid crystal display (LCD). However, the display 12 may be any type of display device.

[0037] In addition, the main body device 2 is provided with a touch panel 13 on the screen of the display 12. In the present embodiment, the touch panel 13 is of a type capable of multi-touch input (for example, a capacitance type). However, the touch panel 13 may be of any type, for example, a type capable of single-touch input (for example, a resistive film type).

[0038] The main body device 2 includes a speaker (that is, the speaker 88 shown in FIG. 6) inside the housing 11. As shown in FIG. 3, speaker holes 11a and 11b are formed in the main surface of the housing 11. Then, the output sound of the speaker 88 is output from these speaker holes 11a and 11b respectively.

[0039] In addition, the main body device 2 includes a left terminal 17 which is a terminal for the main body device 2 to perform wired communication with the left controller 3, and a right terminal 21 for the main body device 2 to perform wired communication with the right controller 4.

[0040] As shown in FIG. 3, the main body device 2 includes a slot 23. The slot 23 is provided on the upper surface of the housing 11. The slot 23 has a shape capable of mounting a predetermined type of storage medium. The predetermined type of storage medium is, for example, a storage medium dedicated to the game system 1 and information processing devices of the same type (for example, a dedicated memory card). The predetermined type of storage medium is used, for example, to store data used in the main body device 2 (for example, save data of an application, etc.) and / or programs executed in the main body device 2 (for example, programs of an application, etc.). In addition, the main body device 2 includes a power button 28.

[0041] The main body device 2 includes a lower terminal 27. The lower terminal 27 is a terminal for the main body device 2 to communicate with the cradle. In the present embodiment, the lower terminal 27 is a USB connector (more specifically, a female connector). When the integrated device or the main body device 2 alone is placed on the cradle, the game system 1 can display an image generated and output by the main body device 2 on a stationary monitor. Further, in the present embodiment, the cradle has a function of charging the placed integrated device or the main body device 2 alone. Further, the cradle has a function of a hub device (specifically, a USB hub).

[0042] FIG. 4 is a six-sided view showing an example of the left controller 3. As shown in FIG. 4, the left controller 3 includes a housing 31. In the present embodiment, the housing 31 has a vertically long shape, that is, a shape that is long in the vertical direction (that is, the y-axis direction shown in FIGS. 1 and 4). The left controller 3 can also be gripped in a vertically long orientation when removed from the main body device 2. The housing 31 has a shape and size that can be gripped with one hand, particularly the left hand, when gripped in a vertically long orientation. Further, the left controller 3 can also be gripped in a horizontally long orientation. When the left controller 3 is gripped in a horizontally long orientation, it may be gripped with both hands.

[0043] The left controller 3 includes an analog stick 32. As shown in FIG. 4, the analog stick 32 is provided on the main surface of the housing 31. The analog stick 32 can be used as a direction input unit capable of inputting a direction. The user can input a direction corresponding to the tilting direction (and an input of a magnitude corresponding to the tilted angle) by tilting the analog stick 32. Note that the left controller 3 may be provided with a cross key or a slide stick capable of slide input instead of the analog stick as a direction input unit. Further, in the present embodiment, it is possible to input by pressing the analog stick 32.

[0044] The left controller 3 is provided with various operation buttons. The left controller 3 has four operation buttons 33 to 36 (specifically, a right direction button 33, a down direction button 34, an up direction button 35, and a left direction button 36) on the main surface of the housing 31. Further, the left controller 3 is provided with a recording button 37 and a -(minus) button 47. The left controller 3 has a first L button 38 and a ZL button 39 at the upper left of the side surface of the housing 31. Also, the left controller 3 has a second L button 43 and a second R button 44 on the side surface of the housing 31 on the side where it is attached when attached to the main body device 2. These operation buttons are used to give instructions according to various programs (for example, an OS program or an application program) executed by the main body device 2.

[0045] Also, the left controller 3 is provided with a terminal 42 for the left controller 3 to perform wired communication with the main body device 2.

[0046] FIG. 5 is a six-sided view showing an example of the right controller 4. As shown in FIG. 5, the right controller 4 includes a housing 51. In the present embodiment, the housing 51 has a vertically long shape, that is, a shape that is long in the vertical direction. The right controller 4 can also be held in a vertically long orientation when removed from the main body device 2. The housing 51 has a shape and size that can be held with one hand, particularly the right hand, when held in a vertically long orientation. Also, the right controller 4 can be held in a horizontally long orientation. When the right controller 4 is held in a horizontally long orientation, it may be held with both hands.

[0047] Similar to the left controller 3, the right controller 4 is provided with an analog stick 52 as a direction input unit. In the present embodiment, the analog stick 52 has the same configuration as the analog stick 32 of the left controller 3. Also, instead of the analog stick, the right controller 4 may be provided with a cross key or a slide stick capable of slide input. Also, similar to the left controller 3, the right controller 4 is provided with four operation buttons 53 to 56 (specifically, an A button 53, a B button 54, an X button 55, and a Y button 56) on the main surface of the housing 51. Further, the right controller 4 is provided with a + (plus) button 57 and a home button 58. Also, the right controller 4 is provided with a first R button 60 and a ZR button 61 at the upper right of the side surface of the housing 51. Also, similar to the left controller 3, the right controller 4 is provided with a second L button 65 and a second R button 66.

[0048] Also, the right controller 4 is provided with a terminal 64 for the right controller 4 to perform wired communication with the main body device 2.

[0049] FIG. 6 is a block diagram showing an example of the internal configuration of the main body device 2. In addition to the configuration shown in FIG. 3, the main body device 2 includes each of the components 81 to 91, 97, and 98 shown in FIG. 6. Some of these components 81 to 91, 97, and 98 may be mounted on an electronic circuit board as electronic components and housed in the housing 11.

[0050] The main body device 2 includes a processor 81. The processor 81 is an information processing unit that executes various information processes to be executed in the main body device 2. For example, it may be composed of only a CPU (Central Processing Unit), or it may be composed of a SoC (System-on-a-chip) including a plurality of functions such as a CPU function and a GPU (Graphics Processing Unit) function. The processor 81 executes various information processes by executing an information processing program (for example, a game program) stored in a storage unit (specifically, an internal storage medium such as a flash memory 84, or an external storage medium mounted on the slot 23, etc.).

[0051] As an example of an internal storage medium built in the main body device 2, the main body device 2 includes a flash memory 84 and a DRAM (Dynamic Random Access Memory) 85. The flash memory 84 and the DRAM 85 are connected to the processor 81. The flash memory 84 is mainly a memory used to store various data (which may be a program) stored in the main body device 2. The DRAM 85 is a memory used to temporarily store various data used in information processing.

[0052] The main body device 2 includes a slot interface (hereinafter abbreviated as "I / F") 91. The slot I / F 91 is connected to the processor 81. The slot I / F 91 is connected to the slot 23, and reads and writes data to and from a predetermined type of storage medium (for example, a dedicated memory card) mounted on the slot 23 in accordance with an instruction from the processor 81.

[0053] The processor 81 appropriately reads and writes data between the flash memory 84 and the DRAM 85, and the above storage media, and executes the above information processing.

[0054] The main body device 2 includes a network communication unit 82. The network communication unit 82 is connected to the processor 81. The network communication unit 82 communicates (specifically, wirelessly communicates) with an external device via a network. In the present embodiment, the network communication unit 82 connects to a wireless LAN and communicates with an external device by a method compliant with the Wi-Fi (registered trademark) standard as a first communication mode. Further, the network communication unit 82 performs wireless communication with another main body device 2 of the same type by a predetermined communication method (for example, communication by a proprietary protocol or infrared communication) as a second communication mode. Note that the wireless communication by the second communication mode enables wireless communication with another main body device 2 arranged within a closed local network area, and realizes a function enabling so-called "local communication" in which data is transmitted and received by direct communication between a plurality of main body devices 2.

[0055] The main body device 2 includes a controller communication unit 83. The controller communication unit 83 is connected to the processor 81. The controller communication unit 83 performs wireless communication with the left controller 3 and / or the right controller 4. The communication method between the main body device 2 and the left controller 3 and the right controller 4 is arbitrary, but in the present embodiment, the controller communication unit 83 communicates with the left controller 3 and the right controller 4 in accordance with the Bluetooth (registered trademark) standard.

[0056] The processor 81 is connected to the left terminal 17, the right terminal 21, and the lower terminal 27 described above. When the processor 81 performs wired communication with the left controller 3, it transmits data to the left controller 3 via the left terminal 17 and receives operation data from the left controller 3 via the left terminal 17. Also, when the processor 81 performs wired communication with the right controller 4, it transmits data to the right controller 4 via the right terminal 21 and receives operation data from the right controller 4 via the right terminal 21. Further, when the processor 81 communicates with the cradle, it transmits data to the cradle via the lower terminal 27. Thus, in the present embodiment, the main body device 2 can perform both wired communication and wireless communication with the left controller 3 and the right controller 4, respectively. Also, when the left controller 3 and the right controller 4 are attached to the main body device 2 as an integrated device or when the main body device 2 alone is attached to the cradle, the main body device 2 can output data (for example, image data or audio data) to a stationary monitor or the like via the cradle.

[0057] Here, the main body device 2 can communicate with a plurality of left controllers 3 simultaneously (in other words, in parallel). Also, the main body device 2 can communicate with a plurality of right controllers 4 simultaneously (in other words, in parallel). Therefore, a plurality of users can simultaneously input to the main body device 2 using respective sets of the left controller 3 and the right controller 4. As an example, it is possible for a first user to input to the main body device 2 using a first set of the left controller 3 and the right controller 4 while a second user inputs to the main body device 2 using a second set of the left controller 3 and the right controller 4.

[0058] Also, the display 12 is connected to the processor 81. The processor 81 displays an image generated (for example, by executing the above-described information processing) and / or an image acquired from the outside on the display 12.

[0059] The main body device 2 includes a codec circuit 87 and speakers (specifically, a left speaker and a right speaker) 88. The codec circuit 87 is connected to the speakers 88 and the audio input / output terminal 25, and is also connected to the processor 81. The codec circuit 87 is a circuit that controls the input / output of audio data to / from the speakers 88 and the audio input / output terminal 25.

[0060] The main body device 2 includes a power control unit 97 and a battery 98. The power control unit 97 is connected to the battery 98 and the processor 81. Although not shown in the figure, the power control unit 97 is connected to each part of the main body device 2 (specifically, each part that receives power supply from the battery 98, the left terminal 17, and the right terminal 21). The power control unit 97 controls the power supply from the battery 98 to each of the above parts based on a command from the processor 81.

[0061] Also, the battery 98 is connected to the lower terminal 27. When an external charging device (for example, a cradle) is connected to the lower terminal 27 and power is supplied to the main body device 2 through the lower terminal 27, the supplied power is charged to the battery 98.

[0062] FIG. 7 is a block diagram showing an example of the internal configuration of the main body device 2, the left controller 3, and the right controller 4. Note that the details of the internal configuration regarding the main body device 2 are shown in FIG. 6, so they are omitted in FIG. 7.

[0063] The left controller 3 includes a communication control unit 101 that communicates with the main body device 2. As shown in FIG. 7, the communication control unit 101 is connected to each component including the terminal 42. In the present embodiment, the communication control unit 101 can communicate with the main body device 2 by both wired communication via the terminal 42 and wireless communication without using the terminal 42. The communication control unit 101 controls the communication method that the left controller 3 performs with respect to the main body device 2. That is, when the left controller 3 is attached to the main body device 2, the communication control unit 101 communicates with the main body device 2 via the terminal 42. Also, when the left controller 3 is removed from the main body device 2, the communication control unit 101 performs wireless communication with the main body device 2 (specifically, the controller communication unit 83). The wireless communication between the controller communication unit 83 and the communication control unit 101 is performed in accordance with, for example, the Bluetooth (registered trademark) standard.

[0064] Further, the left controller 3 includes a memory 102 such as a flash memory. The communication control unit 101 is configured by, for example, a microcomputer (also referred to as a microprocessor), and executes various processes by executing the firmware stored in the memory 102.

[0065] The left controller 3 includes each button 103 (specifically, buttons 33 to 39, 43, 44, and 47). Also, the left controller 3 includes an analog stick (described as "stick" in FIG. 7) 32. Each button 103 and the analog stick 32 output information regarding the operation performed on themselves to the communication control unit 101 repeatedly at an appropriate timing.

[0066] The communication control unit 101 acquires information regarding the input (specifically, information regarding the operation or the detection result by the sensor) from each input unit (specifically, each button 103 and the analog stick 32). The communication control unit 101 transmits operation data including the acquired information (or the information obtained by performing predetermined processing on the acquired information) to the main body device 2. Note that the operation data is repeatedly transmitted at a rate of once every predetermined time. Note that the intervals at which the information regarding the input is transmitted to the main body device 2 may be the same or different for each input unit.

[0067] By transmitting the above operation data to the main body device 2, the main body device 2 can obtain the input performed on the left controller 3. That is, the main body device 2 can determine the operations on each button 103 and the analog stick 32 based on the operation data.

[0068] The left controller 3 includes a power supply unit 108. In the present embodiment, the power supply unit 108 has a battery and a power control circuit. Although not shown, the power control circuit is connected to the battery and is also connected to each part of the left controller 3 (specifically, each part that receives power supply from the battery).

[0069] As shown in FIG. 7, the right controller 4 includes a communication control unit 111 that communicates with the main body device 2. The right controller 4 also includes a memory 112 connected to the communication control unit 111. The communication control unit 111 is connected to each component including the terminal 64. The communication control unit 111 and the memory 112 have the same functions as the communication control unit 101 and the memory 102 of the left controller 3. Therefore, the communication control unit 111 can communicate with the main body device 2 both by wired communication via the terminal 64 and by wireless communication without using the terminal 64 (specifically, communication according to the Bluetooth (registered trademark) standard), and controls the communication method that the right controller 4 performs with the main body device 2.

[0070] The right controller 4 includes the same input units as those of the left controller 3. Specifically, it includes each button 113 and the analog stick 52. These input units have the same functions as those of the left controller 3 and operate in the same manner.

[0071] The right controller 4 includes a power supply unit 118. The power supply unit 118 has the same function as the power supply unit 108 of the left controller 3 and operates in the same manner.

[0072] [2. Overview of Processing in the Game System] Next, with reference to FIGS. 8 to 30, an overview of the processing executed in the game system 1 will be described. In the present embodiment, the game system 1 generates a game image in which terrain objects and characters (for example, player characters operated by players) are arranged in a game space, which is a three-dimensional virtual space, and displays the game image on a display device. Note that in the present embodiment, the display device on which the game image is displayed may be the above-described display 12 or a stationary monitor.

[0073] [2-1. Voxel] In the present embodiment, for some objects in the game space, the shape is defined by voxel data. Here, a voxel is a rectangular parallelepiped (more specifically, a cube)-shaped region arranged in a grid pattern in the game space, and voxel data is data indicating information regarding each voxel. Hereinafter, an object whose shape is defined by voxel data will be referred to as a "voxel object". In the present embodiment, the game system 1 stores voxel data as data for generating voxel objects in the game space for a plurality of voxels set in the game space.

[0074] FIG. 8 is a diagram showing an example of a terrain object that is a voxel object. As shown in FIG. 8, in the present embodiment, a terrain object representing a terrain such as the ground is defined in shape by voxel data (that is, it is a voxel object). Each cube shown in FIG. 8 represents a terrain object. In FIG. 8, the portions that are the sides of the terrain object are shown in thick lines, but this thick line is added for the purpose of making the drawing easier to view, and in reality, it is not necessary for the sides of the terrain object to be shown thickly.

[0075] Note that the terrain object shown in FIG. 8 is generated, for example, according to the rule that "if the parameter included in the voxel data set for a voxel is greater than a predetermined value, a cube is placed at the position of the voxel, and if it is less than or equal to the predetermined value, nothing is placed at the position of the voxel". The terrain object shown in FIG. 8 is shown for the purpose of easily exemplifying the relationship between voxels and voxel objects. In the present embodiment, in reality, for example, like the terrain object shown in FIG. 13 described later, a voxel object is generated according to a rule that results in a complex shape (based on voxel data). Note that the rule for determining the shape of the voxel object based on voxel data is arbitrary. In other embodiments, the game system 1 may generate a voxel object as shown in FIG. 8 or a voxel object as shown in FIG. 13 based on object data.

[0076] Regarding the voxel object, the shape can be changed by changing the voxel data of each voxel. FIGS. 9 and 10 are diagrams showing an example of the state before and after a part of the terrain object shown in FIG. 8 is deleted. That is, when the hatched portion of the terrain object shown in FIG. 9 is destroyed, the terrain object changes to the shape shown in FIG. 10. At this time, the game system 1 can easily erase the terrain object by rewriting the voxel data described later so as to indicate that there is no terrain object for the voxels in the hatched portion. Note that when the game system 1 adds a terrain object, it can easily change the shape of the terrain object by changing the voxel data of each voxel, in the same manner as when erasing the terrain object.

[0077] In this way, the game system 1 can freely change the shape of the voxel object by rewriting the voxel data. For example, when the shape of a terrain object changes as a result of being destroyed for some reason (e.g., a player character strikes the terrain object) in the game, the game system 1 does not directly change the data indicating the outer shape of the terrain object (i.e., the mesh described later), but can freely change the shape of the terrain object by changing the voxel data used for generating the terrain object.

[0078] In the present embodiment, it is assumed that voxels are defined throughout the game space (that is, the voxel space in which voxels are set corresponds to the entire game space). However, the voxel space does not necessarily have to be set throughout the game space and may be set in a partial area of the game space. When the voxel space is set in a partial area of the game space, the shape of the voxel object is defined by voxel data regarding the voxels in the voxel space, and the position of the voxel object in the game space is defined by the position of the voxel space in the game space. Also, in the game space, a main voxel space set throughout the game space and a sub-voxel space set in a partial area of the game space may be set. At this time, the game system 1 stores voxel data for each voxel space.

[0079] FIG. 11 is a diagram showing an example of voxel data. The voxel data includes density data, a first material ID, a second material ID, material mixing ratio data, and state data for each voxel defined in the game space. In the voxel data in the present embodiment, these data are set for each voxel.

[0080] The density data indicates the density, which is an index used to define the shape of the voxel object based on the voxel (specifically, the shape defined by a mesh described later). Although details will be described later, the position and shape of the surface of the voxel object (that is, the mesh described later) are determined based on the above density.

[0081] In this embodiment, the density can take an integer value in the range from a lower limit value (for example, 0) to an upper limit value (for example, 255). In this embodiment, in the game system 1, when the value of the density set for a voxel is high, the ratio of the volume occupied by the region within the voxel object in the voxel tends to be large, and when the value of the density is low, the ratio tends to be small. The surface shape of the voxel object is determined based on the density. Thus, the density is an index that affects the ratio of the volume occupied by the region within the voxel object in the voxel. It can also be said that the density is an index indicating the degree to which the space of the voxel is virtually occupied by the content (that is, the virtual content of the voxel object). For example, when the density is 0, the inside of the voxel is empty, when the density is 255, all of the inside of the voxel is the content of the voxel object, and when the density is a value between 0 and 255, the inside of the voxel can be occupied by the content of the voxel object at a ratio corresponding to the value. Then, based on the above density, the shape of the mesh, that is, the surface shape of the voxel object can be determined. The mesh can also be said to be the surface of the part where the content exists in the voxel, or the boundary between the part where the content exists and the part where it does not exist in the voxel. Note that the volume occupied by the region within the voxel object generated based on the above density does not necessarily have to be exactly the volume corresponding to the ratio indicated by the density. For example, in the method of generating a voxel object as shown in FIG. 8 and the method of generating a voxel object as shown in FIG. 13, even when based on the same density, the volume of the voxel object may be different.

[0082] In other embodiments, the density may indicate either a state in which the volume occupied by the region within the voxel object occupies the entire region within the voxel or a state in which the volume occupied by the region within the voxel object is not included in the region within the voxel. For example, the density data may be data that can only take 0 or 1.

[0083] The first material ID and the second material ID are information indicating the material (in other words, substance) of the voxel. Here, in the present embodiment, materials such as sand, rock, or soil are set for the voxel. Note that in the game system 1, a plurality of types of materials are prepared as materials that can be set for the voxel (refer to the material data shown in FIG. 12). In the present embodiment, up to two materials out of the plurality of types of prepared materials can be set for one voxel. The first material ID is an ID indicating the first material set for the voxel, and the second material ID is an ID indicating the second material set for the voxel. Although details will be described later, the material of the voxel object (that is, the material set for the polygon of the voxel object) is determined based on the material set for the voxel.

[0084] As described above, in the present embodiment, the voxel data includes an ID indicating the material. However, in other embodiments, the voxel data may be a data structure including data directly indicating the content of the material (that is, the name, properties, and drawing setting information described later).

[0085] The material mixing ratio data is an example of data indicating the ratio of each material in the voxel. In the present embodiment, since the number of material IDs set in one voxel is up to two, the material mixing ratio data indicating the ratio of one of the materials indicated by the first material ID and the material indicated by the second material ID can also represent the ratio of the other. In the present embodiment, the material mixing ratio is a value indicating the ratio of the second material to the whole composed of the first material and the second material by a value of 0 or more and 1 or less. For example, when the material mixing ratio set in a certain voxel is 0.4, it means that in the voxel, the first material and the second material are composed in a ratio of 0.6:0.4. Although details will be described later, the appearance and properties of the voxel object are determined based on the material. The material mixing ratio is used to determine the appearance and properties of the voxel object. In other embodiments, the material mixing ratio may be a value indicating the ratio of the first material. Also, the ratio of the materials in the voxel may be represented by respective values indicating the ratio of each material. In particular, in other embodiments, when three or more types of materials can be set instead of up to two types, the ratio of the materials in the voxel is represented as a plurality of values respectively indicating the ratio of each material.

[0086] Note that in the present embodiment, it is not always necessary to set two types of materials in the voxel, and one type of material may be set. For example, when one type of material is set in a certain voxel, the first material ID indicates the material, and the material mixing ratio is set to 0.

[0087] The state data indicates the state set in the voxel. The specific content and number of types of the state data are arbitrary. In the present embodiment, the state data includes data indicating the amount of damage set in the voxel. Note that in other embodiments, the state data may include data indicating, for example, whether the voxel is wet (and the degree thereof).

[0088] As described above, since the voxel data includes the material ID in this embodiment, the game system 1 stores material data that defines the content of the material indicated by the material ID. FIG. 12 is a diagram showing an example of the material data. As shown in FIG. 12, in the material data in this embodiment, for each material, a material ID, a name, a property, and drawing setting information set for the material are associated with each other.

[0089] The name included in the material data is the name set for the material (for example, soil, sand, grass, etc.). Although details will be described later, during the game, the name of the material of the voxel object may be displayed (see FIG. 29). In order to perform such display, the material data includes information on the name of the material.

[0090] The property included in the material data is the property set for the material. The property of the material is the property that the voxel object to which the material is set has in the game. Note that the specific content and the number of types of the property of the material are arbitrary. For example, at least any of the following information may be set as the property of the material. · Hardness · Weight · Slipperiness · Damage setting when the player character touches · Temperature · Whether another object can adhere to the voxel object · Amount of recovery of the player character's physical strength when the player character destroys or acquires the voxel object · Amount of in-game currency acquired by the player character when the player character destroys or acquires the voxel object In other embodiments, information different from the above may be set as the information indicating the property of the material.

[0091] In this embodiment, as information for specifying the properties of a material, the material data includes an ID indicating the property (see FIG. 12). Although not shown, the game system 1 stores property information in which, for each prepared property, the content of the property (for example, a value indicating the above-described weight or slipperiness) is associated with the property ID. By referring to the above property information, the game system 1 can specify the specific content of the property set for the material.

[0092] The rendering settings included in the material data are information indicating settings related to rendering, such as the texture used for rendering the voxel object to which the material is set. In this embodiment, as information on the rendering settings, the material data includes the ID of the texture used for rendering the voxel object to which the material is set (see FIG. 12). Although not shown, the game system 1 stores texture information in which, for each prepared texture, the texture ID and the texture indicated by the texture ID are associated. By referring to the above texture information, the game system 1 can specify the specific content of the texture set for the material. In other embodiments, as information on the rendering settings, in addition to the texture information, any information related to the shading settings may be set. For example, the reflectivity, information related to the normal, etc. may be set.

[0093] Also, the material data may include other data other than the data shown in FIG. 13. For example, the material data may include data related to sound settings. For example, the data related to sound settings may be data that defines the footstep sound output when the player character walks on the voxel object based on the voxel.

[0094] Note that the material data may be data in any format that can identify the properties of the material and / or rendering settings. For example, in other embodiments, the material data may have a data structure that includes data directly indicating the properties of the material and / or rendering settings, instead of a data structure including a material ID and a texture ID.

[0095] [2-2. Update of Voxel Data] During the game, when the above-described voxel data is updated, the voxel object is deformed. In this embodiment, when a game event (hereinafter referred to as an "update event") for updating the voxel object occurs, the game system 1 updates the voxel data. The specific content of the update event is arbitrary. The update event may be, for example, that a character appearing in the game performs an action to deform the voxel object (for example, the player character punches the voxel object), or an event that deforms the voxel object occurs (for example, an object thrown by a character contacts the voxel object, or a bomb explodes).

[0096] FIG. 13 is a diagram showing an example of the game space when an update event occurs. The situation shown in FIG. 13 is a situation where the player character 201 performs a punch action on the terrain object 202 which is a voxel object. Although details will be described later, in the example shown in FIG. 13, the voxel data is updated so that the terrain object 202 around the position hit by the punch action of the player character 201 is erased. As a result, the state where the terrain object 202 is destroyed by the punch action of the player character 201 is expressed.

[0097] In this embodiment, when an update event occurs, the game system 1 sets an update range (update range 203 shown in FIG. 13) for updating the voxel object in the game space. The position, shape, and size of the update range are arbitrary. The position of the update range may be determined based on, for example, the position where the object related to the occurred update event (for example, the player character who performed a punch) and the voxel object are in contact. In the example shown in FIG. 13, the position of the update range 203 may be determined based on the position where the punch by the player character 201 hits, and for example, the hit position or the position a predetermined distance forward from the hit position may be the center position of the update range 203. The shape and size of the update range may be determined in advance to be a shape corresponding to the type of the update event. For example, when an update event due to the punch of the player character 201 occurs, the shape and size of the update range may be determined as a sphere with a predetermined size as shown in FIG. 13. Also, the size of the update range may be determined according to a value indicating the degree of influence of the occurred update event (for example, the strength of the punch or the size of the explosion).

[0098] The game system 1 changes the density for the voxels corresponding to the set update range. Note that the voxels corresponding to the update range are, for example, the voxels within the update range or the voxels overlapping with the update range. As a result of the change in density, the mesh of the voxel object is changed by the process described later, and thus the shape of the voxel object (the visible shape and the shape used for collision determination) is changed. Note that in other embodiments, in addition to changing the density for the voxels included in the update range, the game system 1 may change the material (that is, the first material, the second material, and the material mixing ratio) in the voxels or change the state in the voxels.

[0099] In this embodiment, the game system 1 determines whether a voxel is included in the update range using an SDF (Signed Distance Field). The game system 1 sets an SDF indicating the update range set in the game space, and makes the above determination based on the value of the SDF. The SDF represents, for any position, the signed distance from a defined shape. FIG. 14 is a diagram showing an example of the update range. In the example shown in FIG. 14, a spherical update range is set in the game space. For example, in the example shown in FIG. 14, among the positions in the game space, the SDF value is negative for the positions inside the shape represented by the SDF, and the SDF value is positive for the positions outside the shape represented by the SDF. In this example, it is possible to determine whether or not a position is included in the update range based on whether the SDF value is positive or negative. Also, by using the signed distance value, not only simple inside / outside determination but also processes such as correction and interpolation can be performed.

[0100] In the above, an example in which a change is added to the voxel object such that the voxel object within the update range is deformed as if it were erased has been described, but the changes added to the voxel object using the update range are not limited to this. For example, a change in which a voxel object is newly added within the update range (that is, the volume occupied by the region within the voxel object increases by the amount of the update range) may be added to the voxel object (see FIG. 30 described later). Also, a change may be added to the voxel object such that only the material of the voxels within the update range changes without changing the density of the voxels. Further, a change combining a change in the density of the voxels and a change in the material may be added.

[0101] [2-3. Calculation of Vertices] When the density of the voxels is updated as described above, the game system 1 sets vertices based on the updated voxel data. The above vertices can be the vertices of the mesh of the voxel object. Although details will be described later, in this embodiment, the above vertices are simplified, and the simplified vertices become the vertices of the mesh of the voxel object.

[0102] FIG. 15 is a diagram showing an example of a method for setting vertices. In FIGS. 15 to 25 described below, for the purpose of making the drawings easier to view and the explanations easier to understand, voxels, vertices, meshes, etc. are represented two-dimensionally, but actually vertices and meshes are set in a three-dimensional space based on the voxels in the three-dimensional space. In this embodiment, the game system 1 uses a method of setting vertices at coordinates based on the positions and densities of a plurality of surrounding voxels for a portion where a voxel having a set density indicating its existence (that is, a density equal to or higher than a reference value described later) and a voxel having a set density indicating its non-existence (that is, a density less than the reference value described later) are adjacent. The details of this method will be described below.

[0103] As described above, in the present embodiment, the density set for the voxels is set in the range of 0 to 255. A voxel with a density of 0 is completely in the air, and a voxel with a density of 255 represents a state where it is completely filled. Densities between 0 and 255 are treated interpolatively and are used for vertex determination. And in the present embodiment, voxels with a density equal to or higher than a reference value are virtually treated as being inside the object, and voxels with a density lower than the reference value are virtually treated as being outside the object. It can also be said that voxels with a density equal to or higher than the reference value are virtually treated as voxels indicating existence, and voxels with a density lower than the reference value are virtually treated as voxels indicating non-existence. It is not necessary to define only voxels with a density of 0 as being outside the object (i.e., set the reference value = 1), and the reference value can be, for example, 128. In the example shown in FIG. 15, let the density be 0 in voxel 211 and other outer voxels, 100 in voxel 212 where the density is lower than the reference value, and 150 and 210 in voxels 213 and 214 where the density is equal to or higher than the reference value. In the present embodiment, the game system 1 generates vertices between voxels with a density equal to or higher than the reference value and voxels with a density lower than the reference value. Specifically, for each region spanning eight (four in the drawing) adjacent voxels (the region surrounded by the dotted line in the drawing), a determination is made as to whether to generate a vertex. That is, a vertex is generated in a region spanning both voxels with a density equal to or higher than the reference value and voxels with a density lower than the reference value. The coordinates of the vertex are determined by comparing the densities of adjacent voxels for each of the X, Y, and Z axes and performing interpolation based on the density difference. In addition, by setting normal information that defines the position and orientation of the straight line connecting the vertices, the coordinates of the vertices can be further calculated based on the normal information. Note that the normal information may be held in advance for at least some of the voxels, or if it is not held, the normal information may also be calculated based on the densities of adjacent voxels. In FIG. 15, since the density of voxel 212 is lower than the reference value, in the determination of the presence or absence of vertices, voxel 212 is treated as being outside the object, but the density value itself of voxel 212 is used for the calculation of the coordinates of the generated vertices.If the reference value is set to a value lower than the density of voxel 212, the number of vertices will further increase on the upper right and upper left sides of voxel 212 in FIG. 15.

[0104] By setting the vertices as described above, when generating a mesh that connects each of the set vertices (or each vertex after performing the simplification process described later on each of the set vertices), a shape having a volume that reflects the density of each voxel to some extent can be generated. However, depending on the relationship with adjacent voxels, it is possible that a voxel with a density of 0 includes a region within a part of the object, or a voxel with a density of 255 includes a region outside a part of the object. Also, in this embodiment, since voxels below the reference value are processed as outside the object, the volume is also smaller because the number of vertices is smaller compared to the case of processing them as inside the object. Thus, it is not necessary to calculate the polygon mesh so as to have a volume that exactly corresponds to the density value.

[0105] [2-4. Determination of Vertex Material] The game system 1 determines the material for each of the vertices set as described above. The material of a vertex is determined based on the materials of the voxels around the vertex. The voxels around a vertex are, for example, the voxels used for determining whether to generate the vertex (that is, the voxels that overlap with the "region spanning voxels" described above). Note that in other embodiments, the voxels used for determining the material of a vertex do not have to be the same as the voxels used for determining the generation of the vertex, and they may be different.

[0106] FIG. 16 is a diagram showing an example of a method for determining the material of a vertex. In the example shown in FIG. 16, it is assumed that a vertex 219 is set for four voxels 215 to 218, and the four voxels 215 to 218 are the above-mentioned "voxels around the vertex". In an actual three-dimensional space, the number of voxels around the vertex is eight. Further, in the example shown in FIG. 16, for voxel 215, the density is set to 255, the first material is "sand", and the material mixing ratio is 0 (that is, the first material: the second material = 1:0, or the second material may not be set). For voxel 216, the density is set to 0 (the first and second materials may not be set). For voxel 217, the density is set to 204, the first material is "sand", the second material is "grass", and the material mixing ratio is 0.3 (that is, the first material: the second material = 0.7:0.3). For voxel 218, the density is set to 153, the first material is "soil", the second material is "grass", and the material mixing ratio is 0.4 (that is, the first material: the second material = 0.6:0.4). Also, the coordinates indicating the position of vertex 219 are assumed to be (X, Y) = (0.8, 0.6). Note that the coordinate system of these coordinates has the left-right direction in FIG. 16 as the X coordinate, the up-down direction as the Y coordinate, and the center position of the lower-left voxel 217 (the position of the white circle shown in FIG. 13) among the center positions of voxels 215 to 218 as (0, 0).

[0107] When determining the material of a vertex, the game system 1 calculates an evaluation value for each material in the surrounding voxels based on the density of the material and a weight value based on the distance from the voxel to the vertex. First, the weight value is calculated for each voxel so that it becomes larger as the distance from the center position of the voxel to the vertex is closer. In the present embodiment, when the center position of the voxel is (x1, y1) and the coordinates of the vertex are (x2, y2), the weight value for a certain voxel is calculated according to the following formula (1). (Weight value) = |(1 - x1) - x2|·|(1 - y1) - y2|…(1) In the example shown in FIG. 16, the weight values of each of the voxels 215 to 218 calculated according to the above formula (1) are as follows. (Weight value of voxel 215)=|(1 - 0)-0.8|·|(1 - 1)-0.6| = 0.12 (Weight value of voxel 216)=|(1 - 1)-0.8|·|(1 - 1)-0.6| = 0.48 (Weight value of voxel 217)=|(1 - 0)-0.8|·|(1 - 0)-0.6| = 0.08 (Weight value of voxel 218)=|(1 - 1)-0.8|·|(1 - 0)-0.6| = 0.32

[0108] In addition, the game system 1 calculates the density of the material for each voxel. Here, the density of the material is a value obtained by multiplying the ratio occupied by the material among the materials set in the voxel by the density of the voxel. In the present embodiment, as the density of the voxel, a value obtained by normalizing the values from 0 to 255 described above to values from 0 to 1 is used. In the example shown in FIG. 16, for voxel 215, since the material set is only sand, the above ratio regarding the sand material is 1, and the density of the voxel is 1, so the density of the sand material is 1. For voxel 216, since the density is 0 and no material is set, the density of the material is not calculated. Or, if any material is set, the density of the material is 0. For voxel 217, the above ratios of the set sand material and grass material are 0.7 and 0.3, respectively, and the density of the voxel is 204 / 255 = 0.8, so the density of the sand material is 0.7·0.8 = 0.56, and the density of the grass material is 0.3·0.8 = 0.24. For voxel 218, the above ratios of the set soil material and grass material are 0.6 and 0.4, respectively, and the density of the voxel is 153 / 255 = 0.6, so the density of the soil material is 0.6·0.6 = 0.36, and the density of the soil material is 0.4·0.6 = 0.24.

[0109] Then, the game system 1 calculates the above evaluation value for each material based on the above weight value and the density of the material. In the present embodiment, the evaluation value of the material is a value obtained by attaching a weight according to the weight value for each voxel to the density of the material calculated for each voxel and summing for each surrounding voxel. In the example shown in FIG. 16, for the evaluation value of the sand material, the density of the material for voxel 215 is 1 and the weight value is 0.12, and the density of the material for voxel 217 is 0.56 and the weight value is 0.08, so 1·0.12 + 0.56·0.08 = 0.1648. Also, for the evaluation value of the grass material, the density of the material for voxel 217 is 0.24 and the weight value is 0.08, and the density of the material for voxel 218 is 0.24 and the weight value is 0.32, so 0.24·0.08 + 0.24·0.32 = 0.096. Also, for the evaluation value of the soil material, the density of the material for voxel 218 is 0.36 and the weight value is 0.32, so 0.36·0.32 = 0.1152.

[0110] The game system 1 determines the vertex materials based on the evaluation values for each material. Specifically, a predetermined number of materials are determined as the vertex materials in descending order of the evaluation values. In this embodiment, two materials with large evaluation values are determined as the vertex materials. In the example shown in FIG. 16, since the evaluation values of the materials of sand, grass, and soil are 0.1648, 0.096, and 0.1152 respectively, the vertex materials are determined as the sand material and the soil material. Also, the game system 1 calculates the ratio of the two determined materials based on the above evaluation values. In this embodiment, the ratio of the two materials may be expressed as a second material ratio, which is the ratio of the second material to the whole, similar to the above material mixing ratio. In the example shown in FIG. 16, for example, when the first material is the soil material and the second material is set as the sand material, the above second material ratio is shown as 0.1648 / (0.1648 + 0.1152) ≈ 0.59. Note that in other embodiments, as the value representing the ratio of the two materials, a value indicating the ratio of the first material may be used. Also, respective values indicating the ratio of each material may be used.

[0111] In this embodiment, the game system 1 generates and stores vertex data indicating the position of the vertex, the material IDs of the first and second materials set for the vertex, and the ratio of the materials. However, the method of managing the materials set for the vertex is arbitrary. In other embodiments, the vertex data may be a data structure including data directly indicating the contents of the first and second materials.

[0112] As described above, in the present embodiment, for each vertex, for the material IDs included in the voxel data of a plurality of surrounding voxels, a priority parameter (for example, an evaluation value) for each material ID is calculated based on the voxel data. Then, based on the priority parameter, up to a predetermined number (here, two) of material IDs with high priority are selected and determined as the material ID of the vertex. Note that the specific parameter used as the priority parameter is not limited to the above evaluation value. For example, in other embodiments, an evaluation value calculated using the density of the material instead of the above weight value may be used as the priority parameter.

[0113] In the present embodiment, an evaluation value, which is an example of the priority parameter, is calculated based on the densities of a plurality of voxels around the vertex so that the priority of the material set in the voxel with a higher density becomes higher (that is, the evaluation value of the material becomes larger and the material is more likely to be selected). According to this, the material of the vertex can be determined by reflecting the magnitude of the density set in the voxel.

[0114] Also, in the present embodiment, an evaluation value, which is an example of the priority parameter, is calculated based on the distance from the reference position (specifically, the center position) of a plurality of voxels around the vertex to the vertex so that the priority of the material set in the voxel closer to the vertex becomes higher. According to this, the material of the vertex can be determined by reflecting the distance between the voxel and the vertex.

[0115] Also, in the present embodiment, it can be said that an evaluation value, which is an example of the priority parameter, is calculated based on the material mixing ratio of a plurality of voxels around the vertex so that the priority of the material with a higher material mixing ratio becomes higher. According to this, when a plurality of materials are set in one voxel, the material of the vertex can be determined by reflecting the ratio of each material.

[0116] [2-5. Simplification of Vertex] In this embodiment, the game system 1 simplifies each vertex calculated as described above. That is, the game system 1 reduces the number of vertices by grouping some of the vertices calculated as described above and replacing them with a single vertex. Although details will be described later, the coordinates (i.e., positions) and materials of the vertices to be replaced are set based on a plurality of vertices before replacement. By such simplification, the number of vertices and polygons constituting the mesh of the voxel object can be reduced, and the amount of memory used for processing and the processing load can be reduced.

[0117] In this embodiment, the game system 1 simplifies by expressing each vertex using an SVO (Sparse Voxel Octree). FIG. 17 is a diagram showing an example of vertex simplification. In FIG. 17, one square indicated by a solid line shown in FIG. 17(a) represents one vertex division region. Here, the vertex division region is a square region having the center position of the voxel as a vertex (in the actual three-dimensional space, the vertex division region is a cube or a rectangular parallelepiped), and is a region having the dotted lines in FIGS. 15 and 16 described above as sides. Further, in FIG. 17, the vertex division region in which the character "v" is shown inside indicates the vertex division region in which vertices are set.

[0118] In this embodiment, the game system 1 determines whether or not simplification is possible for the vertices within a predetermined number (four in FIG. 17, eight in the actual three-dimensional space) of mutually adjacent vertex division regions. When it is determined that simplification is possible, simplification is performed on the vertices within the predetermined number of vertex division regions. For each vertex group including the predetermined number of vertices, simplification is performed to replace the vertices included in the vertex group with one vertex under certain conditions.

[0119] (a) of FIG. 17 shows the state before simplification. In the example shown in FIG. 17, it is assumed that the vertex division regions within the range surrounded by the dotted line can be simplified. At this time, the game system 1 performs simplification so that the vertices within each of the above-mentioned predetermined number of vertex division regions determined to be simplifiable are replaced by one vertex (see FIG. 17(b)). As a result, the vertices within the above-mentioned predetermined number of vertex division regions are simplified to one vertex.

[0120] In this embodiment, the game system 1 performs simplification in multiple stages. The number of stages is arbitrary, but in FIG. 17, the first two stages will be illustrated and described. (b) of FIG. 17 shows the state after the first-stage simplification, and (c) of FIG. 17 shows the state after the second-stage simplification. In the second-stage simplification, it is determined whether simplification is possible for the vertices generated by the first-stage simplification. In the example shown in FIG. 17, as a result of determining that the vertex division region within the range surrounded by the dotted line in FIG. 17(b) can be simplified, the vertices of the vertex division region are simplified, resulting in the state shown in FIG. 17(c). Note that the determination conditions for whether the first-stage simplification is possible and the determination conditions for whether the second-stage simplification is possible may be the same or different.

[0121] FIG. 18 is a diagram showing an example of the tree structure of SVO. As shown in FIG. 18, SVO has an octree structure. The tree structure of SVO in the present embodiment is a five-layer tree structure having 4096 leaf nodes corresponding to four levels of simplification (FIG. 18 shows a part of the five-layer tree structure). To the leaf nodes in the bottom layer of the tree structure, vertices calculated based on voxel data by the method described in [2-3. Calculation of vertices] above (that is, vertices before simplification) are associated. To eight leaf nodes with the same parent node, eight vertices included in the same vertex group are respectively associated. To the parent node of the eight leaf nodes, vertices obtained by simplifying the respective vertices corresponding to the eight leaf nodes (that is, vertices by the first-stage simplification) are associated. Further, to the parent node one level above the eight parent nodes, vertices obtained by simplifying the respective vertices by the first-stage simplification (that is, vertices by the second-stage simplification) are associated. In this way, to the parent node of eight nodes at a certain level, vertices obtained by simplifying the vertices corresponding to the eight nodes are associated.

[0122] In addition to information on the vertex position corresponding to the node, various types of information regarding the vertex may be associated with each node. Although details will be described later, in the present embodiment, for example, a material reduction flag described later is associated with a leaf node. Also, for example, information indicating an error described later is associated with a parent node.

[0123] Note that although details will be described later, in the present embodiment, in order to determine whether simplification is possible, position information of a vertex calculated as a candidate for a vertex after simplification (a provisional vertex described later) and error information regarding the provisional vertex are calculated. In the present embodiment, these pieces of information are associated with and stored in a node even when simplification is determined to be impossible and simplification is not performed, and may be used in post-simplification processing (for example, mesh generation processing described later).

[0124] Regarding the determination of whether simplification is possible, the specific method is arbitrary. In the present embodiment, as conditions for the above determination, conditions related to the shape of the voxel object and conditions related to the material are used. In the present embodiment, when both the conditions related to the shape of the voxel object and the conditions related to the material are satisfied, it is determined that simplification is possible, and when at least one of the conditions related to the shape of the voxel object and the conditions related to the material is not satisfied, it is determined that simplification is impossible.

[0125] The conditions related to the shape are, for example, that the shape formed by each vertex before simplification and the shape formed by each vertex after simplification are not significantly changed. For example, whether the shape formed by each vertex is not significantly changed before and after simplification can also be determined by calculating an index indicating the error between the mesh before simplification and the mesh after simplification and determining whether the index is less than or equal to a predetermined allowable value. Also, for example, when the shape formed by each vertex before simplification is a hollow shape, while the shape formed by each vertex after simplification is not a hollow shape (that is, information indicating hollowness is lost due to simplification), it is also determined that the conditions related to the shape are not satisfied. Whether the above situation occurs can be determined, for example, based on the density of each voxel corresponding to the vertex division region to be determined. Also, for example, when the shape formed by each vertex before simplification is a shape that can only be represented by two or more vertices and cannot be represented by a single vertex, it is also determined that the conditions related to the shape are not satisfied. Note that as the conditions related to the shape of the voxel object, the same conditions as those of the conventional method using SVO may be used.

[0126] Also, as conditions regarding the material, in the present embodiment, two conditions, i.e., a first condition and a second condition, are used. The first condition is a condition regarding the number of types of materials set for each vertex within the above-mentioned predetermined number of vertex division regions that are targets for simplification. FIG. 19 is a diagram showing an example of the first condition regarding the material. (a) of FIG. 19 shows a case where the materials of vertices 221 to 224 are (grass), (grass), (grass and soil), and (grass and soil), respectively, and (b) of FIG. 19 shows a case where the materials of vertices 221 to 224 are (grass and sand), (grass), (grass and soil), and (grass and soil), respectively. In the present embodiment, the first condition is that the total number of types of materials set for each of the above-mentioned vertices that are targets for simplification is equal to or less than a predetermined number. For example, the condition is that it is equal to or less than the number of materials that can be set for one vertex. In the present embodiment, the above-mentioned predetermined number is 2. For example, in the case of (a) of FIG. 19, the total number of types of materials set for each of the vertices 221 to 224 that are targets for simplification is two types, i.e., grass and soil, so the first condition is satisfied. At this time, on the condition that the second condition and the above-mentioned condition regarding the shape of the object are satisfied, each of the vertices 221 to 224 is determined to be simplifiable. On the other hand, in the case of (b) of FIG. 19, the total number of types of materials set for each of the vertices 221 to 224 that are targets for simplification is three types, i.e., grass, soil, and sand, so the first condition is not satisfied. At this time, regardless of whether the second condition and the above-mentioned condition regarding the shape of the object are satisfied, each of the vertices 221 to 224 is determined to be non-simplifiable.

[0127] In the game system 1, even materials that are strictly classified into different types may be prepared with the same set properties but different appearances. For some of such multiple types of materials, they may be regarded as the same type in the determination of conditions related to the materials for the determination. For example, regarding soil materials, there may be cases where multiple types of soil materials with the same properties but similar appearances (e.g., texture color and pattern) are prepared. In such cases, the game system 1 may regard the multiple types of soil materials as the same type and perform the determination of conditions related to the materials.

[0128] Here, in the present embodiment, regarding vertices, similar to voxels, up to two types of materials can be set. On the other hand, in the present embodiment, when the total number of types of materials set for each vertex to be simplified is three or more, simplification is not performed. That is, when the total number of types of materials exceeds the number of materials that can be set for one vertex, simplification is not performed. Therefore, even if the number of vertices is reduced by simplification, the information on the materials set for the vertices will not be lost due to simplification, and the material information can be maintained.

[0129] The second condition is that each vertex included in the vertex group to be determined is (a) not a vertex where material reduction has been performed, or (b) not a vertex simplified based on a vertex where material reduction has been performed. Here, the "vertex where material reduction has been performed" is a vertex where the number of types of materials used in the setting of the vertex has been reduced to the number of types of materials set for the vertex. In other words, a vertex where material reduction has been performed is a vertex where the number of types of materials used in the setting of the vertex is greater than the number of types of materials set for the vertex. In the present embodiment, when determining the material of a vertex based on voxel data (see [2-4. Determination of Vertex Material] above), if the total number of types of materials set for each voxel around the vertex is greater than the number of types of materials set for the vertex, the vertex becomes a "vertex where material reduction has been performed". For example, in the example shown in FIG. 16, the total number of types of materials set for each voxel around the vertex is 3 (specifically, sand, grass, soil), and the number of types of materials set for the vertex is 2 (specifically, sand, soil), so the vertex becomes a "vertex where material reduction has been performed". In the present embodiment, when the game system 1 determines the material of a vertex, it stores a material reduction flag indicating whether the vertex is a vertex where material reduction has been performed in association with the node of the vertex in the SVO. The game system 1 determines the second condition by referring to the material reduction flags associated with the respective nodes corresponding to the respective vertices included in the vertex group.

[0130] Note that the condition in (a) above is a condition for determining whether to perform the first-stage simplification, and the condition in (b) above is a condition for determining whether to perform the simplification after the second stage. For example, in the determination of the first-stage simplification, if among the vertices included in the vertex group, there is a vertex where material reduction has been performed, the second condition will not be satisfied according to the condition in (a). Also, in the determination of the simplification after the second stage, if among the vertices included in the vertex group, there is a vertex simplified based on a vertex where material reduction has been performed, the second condition will not be satisfied according to the condition in (b). Note that as described above, in this embodiment, even when it is determined that the first-stage simplification is impossible, a virtual vertex calculated assuming that the simplification has been performed is calculated and held in the node. When it is determined that the first-stage simplification is impossible, the determination of the simplification after the second stage is performed using the above virtual vertex.

[0131] Here, since the polygon including the vertex where material reduction has been performed does not reflect all types of materials set in the voxel, there is a possibility of an unnatural appearance. Also, when simplifying the vertex group including the vertex where material reduction has been performed, there is a possibility that the area of the unnatural-looking polygon as described above will increase and become more prominent. In contrast, in this embodiment, by including the second condition in the simplification condition, the vertex group including the vertex where material reduction has been performed will not be simplified, so it is possible to suppress an increase in the area of the unnatural-looking polygon.

[0132] Note that in the determination of the second condition, similar to the determination of the first condition, the game system 1 may regard a plurality of types of materials with the same set properties but different appearances as the same type of material. For example, when the number of types of materials used for vertex setting is three, including two types of materials with the same set properties but different appearances, and the material set for the vertex is two types including one of the two types of materials, the game system 1 may not regard the vertex as a vertex where material reduction has been performed.

[0133] In this embodiment, when both the first condition and the second condition are satisfied, the conditions regarding the material are satisfied. In this case, on the condition that the conditions regarding the shape of the above object are satisfied, the simplification conditions are satisfied. On the other hand, when at least one of the first condition and the second condition is not satisfied, the conditions regarding the material are not satisfied. In this case, regardless of whether the conditions regarding the shape of the above object are satisfied, the simplification conditions are not satisfied.

[0134] Note that the specific content of the conditions regarding the material is arbitrary. In other embodiments, the game system 1 may, for example, determine that the conditions regarding the material are satisfied when at least one of the first condition and the second condition is satisfied. Also, for example, the conditions regarding the material may not include either or both of the first condition and the second condition, or may include conditions different from the first condition and the second condition.

[0135] In this embodiment, the material of the simplified vertex is determined based on the material of each vertex before simplification. Specifically, the game system 1 sets one or two types of materials set for the vertices before simplification as the first material and the second material for the vertices after simplification. Thereby, the information of the material can be maintained. Note that the ratio of the materials after simplification is determined based on the ratio of the materials of each vertex before simplification. In this embodiment, the ratio of the materials after simplification is calculated in the same manner as the method of calculating the ratio of the materials of each vertex using the above evaluation value. That is, the game system 1 calculates a weight value based on the distance between the vertices after simplification and the vertices before simplification, and based on the weight value and the density of the material at the vertices before simplification (note that the evaluation value of the material described in [2-4. Determination of the material of the vertex] above can be used as the density of the material here), calculates an evaluation value for each material. Then, the ratio of the materials is calculated based on the calculated evaluation value of each material.

[0136] In this embodiment, when updates are made to some of the voxels, the game system 1 performs a simplification process on the tree structure including the vertices updated in response to the updates. Specifically, when a node corresponding to a vertex updated in response to a voxel update is included in the SVO tree structure (see FIG. 18) having 4096 leaf nodes, a simplification process is performed on each vertex corresponding to each node of the tree structure. In the above case, the game system 1 determines whether the simplification condition is satisfied for each vertex, and performs simplification when the condition is satisfied. On the other hand, in the above tree structure, when the vertices updated in response to the voxel update are not included, no simplification process is performed on each vertex included in the tree structure. As described above, in this embodiment, by performing simplification on the vertices in the range including the location where the voxel update is made, the processing load due to simplification can be reduced.

[0137] [2-6. Generation of Mesh] In this embodiment, based on each vertex simplified as described above, a mesh of the voxel object is generated. FIG. 20 is a diagram showing an example of a mesh generated based on each vertex. Note that the square shown in FIG. 20 indicates the above-described vertex division region, or a vertex division region in which a plurality of vertex division regions are combined into one by simplification. As shown in FIG. 20, the game system 1 generates a mesh composed of polygons having straight lines connecting adjacent vertices of the vertex division region as sides. Each polygon constituting the mesh is a triangle or a quadrilateral.

[0138] In this embodiment, the game system 1 generates two types of meshes: a display mesh and a determination mesh. The display mesh is a mesh used for displaying the voxel object. The determination mesh is a mesh used for collision determination of the voxel object. Although details will be described later, the game system 1 can perform processing using meshes suitable for displaying and collision determination of the voxel object by using the above two types of meshes.

[0139] In this embodiment, the game system 1 generates the display mesh and the determination mesh based on the data of the above-described SVO (that is, based on each simplified vertex). According to this, by sharing the vertex data used for generating the two types of meshes, the processing efficiency can be improved. Note that in other embodiments, the game system 1 may not perform vertex simplification and may generate the display mesh and / or the determination mesh based on non-simplified vertices.

[0140] In this embodiment, the game system 1 generates the determination mesh to have a simpler shape than the display mesh. Specifically, the game system 1 reduces the number of vertices of the determination mesh compared to the number of vertices of the display mesh. Here, in this embodiment, the SVO data is data that holds the data of the vertices before simplification and the data of the simplified vertices in an octree structure, and also includes the data used for determining whether simplification is possible. This data includes, for example, the data of vertices (referred to as temporary vertices) calculated as candidates for the vertices after simplification, and the data of the above-mentioned index indicating the error between the vertices before simplification and the temporary vertices. Specifically, data of an index indicating the error related to the temporary vertex may be associated with the node of the temporary vertex among the nodes of the octree structure of the SVO. For example, the game system 1 may use, for the generation of the determination mesh, vertices among the temporary vertices for which the above index is equal to or less than a predetermined threshold (this threshold is set to be larger than the above allowable value). When vertex simplification is performed when the error is within the allowable range, the allowable range for the simplification of the determination mesh may be set to a wider range (for example, a range including the allowable range for the simplification of the display mesh) than the allowable range for the simplification of the display mesh. According to this, the number of vertices of the determination mesh can be made less than the number of vertices of the display mesh. By making the number of vertices of the determination mesh less than the number of vertices of the display mesh, the processing load due to collision determination can be reduced. Also, since the number of vertices of the display mesh is not excessively reduced, the appearance of the voxel object can be expressed in detail.

[0141] Note that in other embodiments, the display mesh and the determination mesh may be generated based on the same data or different data. Also, the display mesh and the determination mesh may have the same shape (however, even in this case, the materials set for both may be different). Also, the number of vertices of the determination mesh may be the same as the number of vertices of the display mesh, or may be more than the number of vertices of the display mesh.

[0142] [2-6-1. Determination of the Material of the Display Mesh] Next, an example of a method for determining the material and appearance of the display mesh will be described. In the present embodiment, the game system 1 determines the material for each polygon constituting the display mesh. Although details will be described later, in the present embodiment, the polygon corresponding to the above polygon is drawn using up to two textures corresponding to up to two materials. Therefore, the game system 1 ensures that for each polygon constituting the mesh, ultimately, the number of materials set for one polygon is two or less. In other embodiments, three or more materials may be set. For example, in embodiments where there are three or more materials for voxels and vertices, the same number of materials may be set for the polygon.

[0143] In the present embodiment, a quadrilateral may be formed as the polygon constituting the display mesh (see Fig. 20). When determining the material of the display mesh, the game system 1 first divides the quadrilateral constituting the display mesh into two triangles under certain conditions. Hereinafter, with reference to Fig. 21, the process of dividing the quadrilateral into two triangles will be described.

[0144] Fig. 21 is a diagram showing an example in which a quadrilateral constituting the mesh is divided into two triangles. (a) shown in Fig. 21 shows the quadrilateral before division formed by vertices 231 to 234, which are part of the vertices of the mesh, and (b) shown in Fig. 21 shows the two triangles obtained by dividing the quadrilateral. In the example shown in Fig. 21, assume that the materials of each of the vertices 231 to 234 are grass, soil, sand and grass, and grass, respectively.

[0145] In this embodiment, when there are three or more types of materials set at each vertex of a quadrilateral in total, the game system 1 determines whether the division condition is satisfied. In this embodiment, the division condition is that by dividing the quadrilateral into two triangles, the total number of types of materials set at each vertex of the triangles can be made two or less. When the division condition is satisfied, the game system 1 divides the quadrilateral into two triangles such that the total number of types of materials set at each vertex is two or less. In the example shown in FIG. 21, the materials set at each vertex 231 to 234 forming the quadrilateral are three types: grass, soil, and sand. Also, when the above quadrilateral is divided into a triangle formed by vertices 231, 232, 234 and a triangle formed by vertices 231, 233, 234, the materials set at each vertex of the former triangle are two types: sand and grass, and the materials set at each vertex of the latter triangle are two types: grass and soil (see (b) of FIG. 21). Therefore, for the above quadrilateral, the division condition is satisfied, so the game system 1 divides the quadrilateral into two triangles.

[0146] Note that since there are two ways to divide a quadrilateral into two triangles, when the division condition is satisfied for at least one of the two ways of dividing the triangles, the game system 1 performs the above division in the way that satisfies the division condition. On the other hand, when the division condition is not satisfied for the triangles divided by either of the two ways, the division is performed by either way.

[0147] By performing the division as described above, the game system 1 can generate two triangles in which the materials set at each vertex are two or less so as not to lose the information of three or more types of materials set at each vertex of the quadrilateral as much as possible. Here, as described above, each polygon constituting the mesh is drawn using up to two types of textures. Therefore, by performing the above division, the game system 1 can draw a polygon using two types of textures so as not to lose the information of the materials set at each vertex as much as possible.

[0148] In this embodiment, the game system 1 sets a polygon corresponding to the polygon after the above division. That is, the vertices of the polygon after the above division become the vertices of the polygon of the display mesh.

[0149] In this embodiment, for each polygon constituting the display mesh, when there are three or more types of materials set for each vertex of one polygon in total, the game system 1 determines the material of the polygon by selecting two types of materials. FIG. 22 is a diagram showing an example of a method for determining the material of a polygon constituting the display mesh. In the example shown in FIG. 22, for vertex 241 of the triangular polygon constituting the display mesh, let the first material be "grass", the second material be "soil", and the material ratio of the first material: the second material = 0.8:0.2. Also, for vertex 242 of the above polygon, let the first material be "grass", the second material be "sand", and the material ratio of the first material: the second material = 0.5:0.5. Also, for vertex 243 of the above polygon, let the first material be "sand", the second material be "soil", and the material ratio of the first material: the second material = 0.7:0.3.

[0150] When there are three or more types of materials set for each vertex of the polygon in total, the game system 1 calculates a determination value for each material. The determination value is calculated as the value obtained by summing the ratios for each vertex where the material is set. Then, the game system 1 selects two materials in order from the ones with larger determination values as the materials of the polygon. In the example shown in FIG. 22, the determination value of the grass material is 0.8 + 0.5 = 1.3, the determination value of the sand material is 0.5 + 0.7 = 1.2, and the determination value of the soil material is 0.2 + 0.3 = 0.5. Therefore, as the materials of the polygon shown in FIG. 22, the grass and sand materials are selected (see (a) in FIG. 22).

[0151] The specific method of selecting the material of the polygon of the display mesh is arbitrary. In other embodiments, the material of the polygon of the display mesh may be selected by any method based on the information set at the vertices of the polygon. For example, for the material of the polygon of the display mesh, the material with the largest ratio at one vertex is specified for each vertex, and the material with the largest number of times specified for each vertex may be selected as the material of the polygon.

[0152] In this embodiment, the material of the polygon selected as described above is indicated by the materials set at the respective vertices of the polygon. That is, when the material of the polygon is selected, the game system 1 changes the materials set at the respective vertices of the polygon (that is, the material IDs included in the vertex data) to the selected material. In the example shown in FIG. 22, for vertices 241 and 243, before the selection of the material of the polygon, the materials of grass and soil, and sand and soil are set respectively (see (a) of FIG. 22). When the materials of grass and sand are selected as the material of the polygon as described above, the materials set at each of vertices 241 and 243 are changed to grass and sand (see (b) of FIG. 22). Note that for vertex 242, since the material set before the selection is the same as the selected material of the polygon, the material is not changed. As described above, when two types of materials are selected as the material of the polygon, the information of the materials of the third and subsequent types set at each vertex of the polygon is erased.

[0153] In addition, the game system 1 changes the ratio of the materials set for each vertex in accordance with the change of the materials set for the vertices. For example, for vertex 241, the content is changed from the first material being grass and the second material being soil to the first material being grass and the second material being sand. Here, since the ratio of the sand material is 0, the material ratio is the first material: the second material = 1:0. In this way, the above change formally changes the material of each vertex in order to represent the material of the polygon by the materials of each vertex of the polygon.

[0154] According to the above, since the material set for each vertex of one polygon is only the material corresponding to the texture used for the drawing described later, it is possible to facilitate the execution of the drawing process using the texture.

[0155] Note that due to the above change, it may be the case that all the materials for a certain vertex are changed (that is, none of the materials before the change match the materials after the change). Such a case is, for example, when the material set for the vertex before the change is soil and the materials selected as the material of the polygon are grass and sand. In such a case, the ratio of the materials at the vertex may be set based on the ratio of the materials at the other vertices of the polygon. For example, in the above example, when the first material set for one of the other vertices of the triangular polygon is grass and the material ratio is grass: sand = 1:0, and the material set for another vertex is sand and the material ratio is sand: grass = 1:0, the material ratio at the vertex may be set to grass: sand = 0.5:0.5. In addition, the game system 1 may determine the ratio of the materials at the vertex in consideration of the distance between the vertex and the other vertices (for example, based on a weight value that increases as the distance gets closer).

[0156] As described above, in this embodiment, for each polygon, the game system 1 selects up to a predetermined number (here, 2) of the material IDs set for the vertices included in the polygon (that is, the material IDs set for the vertices of the polygon corresponding to the polygon) and determines them as the material ID of the polygon. According to this, the game system 1 can perform the drawing process while suppressing the number of textures used while reflecting the material set for the vertices in the appearance of the polygon.

[0157] In this embodiment, for all the materials of the vertices constituting the polygon, when the number of the materials is less than or equal to the predetermined number, the game system 1 determines the material as the material of the polygon, and when the material exceeds the predetermined number, based on the priority parameter of each vertex (specifically, based on the determination value calculated based on the above-described evaluation value), it selects a predetermined number of materials with high priority and determines them as the material of the polygon. As a result, even when a total of more than the predetermined number of materials are set for each vertex, the material of the polygon can be set to a predetermined number or less of materials considering the priority.

[0158] As described above, in this embodiment, the first and second materials set for each vertex of one polygon are changed to be two types of materials set for the polygon. Here, when such a change is made, there is a possibility that a discrepancy may occur in the first and second materials set for the vertices shared by two adjacent polygons.

[0159] FIG. 23 is a diagram showing an example of materials set for each vertex of two adjacent polygons. FIG. 23 shows a state (FIG. 21(b)) in which two polygons are formed by the respective vertices 231 to 234 shown in FIG. 21. In the example shown in FIG. 23, since the materials of the first polygon formed by vertices 231, 233, and 234 are determined to be grass and sand, the first and second materials of these vertices should be set to grass and sand, respectively. On the other hand, since the materials of the second polygon formed by vertices 231, 232, and 234 are determined to be grass and soil, the first and second materials of these vertices should be set to grass and soil, respectively. Therefore, in the example shown in FIG. 23, there is a conflict in the materials to be set for vertices 231 and 234 shared by the two polygons.

[0160] Therefore, in the present embodiment, when there is a conflict in the materials to be set for a vertex shared by two polygons, the game system 1 adds another vertex at the same position with respect to the vertex. FIG. 23(b) is a diagram showing an example of a state in which vertex 231' is added for vertex 231 and vertex 234' is added for vertex 234. In the example of FIG. 23, for vertices 231 and 234, the game system 1 sets the first and second materials to grass and sand according to the materials of the first polygon. For vertices 231' and 234', the game system 1 sets the first and second materials to grass and soil according to the materials of the second polygon. In this way, by formally setting two vertices as the vertices shared by the two polygons (that is, generating two vertex data with the same position and different materials), it is possible to suppress the occurrence of conflicts in the materials set for the vertices.

[0161] The game system 1 generates a display mesh composed of polygons in which the vertices and materials are determined as described above. Further, the game system 1 performs the drawing of the voxel object by performing the drawing of the polygon based on the information of the materials set for each vertex (that is, the first material and the second material).

[0162] FIG. 24 is a diagram showing an example of applying a texture to a polygon. FIG. 24 shows a triangular polygon formed by the respective vertices 241 to 243 shown in FIG. 22. Note that the materials set for the respective vertices 241 to 243 are those shown in FIG. 22(b).

[0163] Regarding the positions of the vertices of the polygon, drawing is performed by mapping that blends the texture of the first material and the texture of the second material set for the vertex at the ratio of the materials set for the vertex (that is, using the ratio as the blend ratio). Note that the textures of the first and second materials used for drawing are the textures indicated by the drawing setting information associated with the respective material IDs associated with the vertex data in the above-described material data (see FIG. 12). In the example shown in FIG. 24, regarding the position of vertex 241, since the material ratio is grass: sand = 1:0, drawing is performed using only the grass texture. Also, regarding the position of vertex 243, since the first material is sand and the material ratio is sand: grass = 1:0, drawing is performed using only the sand texture. Further, regarding the position of vertex 242, since the first material is grass, the second material is sand, and the material ratio is grass: sand = 0.5:0.5, drawing is performed by blending the grass texture and the sand texture at a blend ratio of 0.5:0.5.

[0164] Also, for positions other than the vertices of the polygon, the game system 1 determines the blend rate by interpolating the blend rates at each vertex. Then, the textures of the two materials set for each vertex are drawn by a mapping that blends based on the interpolated blend rate. Note that the specific method of interpolation is arbitrary. As an example, the blend rate between vertices is linearly interpolated. In FIG. 24, the positions where the ratio of the texture of the grass material is applied is high are shown in white, and the positions where the ratio of the texture of the sand material is applied is high are shown in black. In the example shown in FIG. 24, the grass texture is applied at vertex 241. As it approaches vertex 243, the blend ratio of the sand texture increases. At the position of vertex 242, the blend rate of grass and sand is 1:1, and only the sand texture is applied at the position of vertex 243. In this way, by blending and drawing the two textures set for the polygon (i.e., set for each vertex of the polygon) at a blend rate according to the ratio of the materials, the appearance at the boundary between different materials in the display mesh can be made natural. As a result, the appearance of the display mesh with multiple types of materials set can be made natural.

[0165] [2-6-2. Determination of the Material of the Mesh for Judgment] Next, an example of a method for determining the material of the mesh for judgment will be described. Although details will be described later, in this embodiment, collision detection of the voxel object is performed using the mesh for judgment, and processing may be executed according to the material of the voxel object for which collision is detected. Therefore, in this embodiment, the material is also determined for the mesh for judgment.

[0166] In this embodiment, for each polygon that constitutes the determination mesh, the game system 1 ensures that there is one type of material set for each polygon. Specifically, the game system 1 determines the material set for the polygon of the determination mesh based on the material information set at the vertices of the polygon (that is, the information on the first and second materials and the ratio of the materials).

[0167] FIG. 25 is a diagram showing an example of a method for determining the material of a polygon that constitutes a determination mesh. FIG. 25 shows an example of determining the material for a triangular polygon formed by each of the vertices 241 to 243 shown in FIG. 22. Note that the materials set at each of the vertices 241 to 243 are those shown in FIG. 22(a).

[0168] When determining the material of a polygon, the game system 1 calculates a determination value for each material set at each vertex of the polygon. In this embodiment, the method for calculating the determination value is the same as the method for calculating the determination value used for selecting the material of the polygon of the display mesh. Note that the specific method for calculating the determination value is arbitrary. In other embodiments, the determination value may be calculated by any method based on the information set at the vertices of the polygon of the determination mesh.

[0169] In the example shown in FIG. 25, for each material, the determination value is as follows: for the grass material, the determination value is 1.3; for the sand material, the determination value is 1.2; and for the soil material, the determination value is 0.5, similar to the case shown in FIG. 22 described above. Therefore, the grass material is selected as the material of the polygon shown in FIG. 25.

[0170] As described above, in this embodiment, for each polygon, the game system 1 selects up to a predetermined number (here, 1) of the material IDs set for the vertices included in the polygon (that is, the material IDs set for the vertices of the polygon corresponding to the polygon), and determines them as the material IDs of the polygon. According to this, the game system 1 can suppress the number of materials set for the determination mesh to be equal to or less than the predetermined number. Thereby, it is possible to suppress the complexity of the processing according to the type of material, which is performed according to the result of the collision determination using the determination mesh. Note that the method of determining the material of the polygon of the determination mesh is arbitrary and is not limited to the above. In other embodiments, the material of the polygon of the determination mesh may be determined by any method based on the information set for the vertices of the polygon.

[0171] Also, in this embodiment, up to two types of materials are set for the polygons of the display mesh, while only one type of material is set for the polygons of the determination mesh. According to this, for the polygons of the display mesh, two types of textures can be used to achieve a natural appearance, and for the determination mesh, it is possible to suppress the complexity of the processing performed according to the result of the collision determination using the determination mesh. Note that in other embodiments, the number of types of materials that can be set for the polygons of the display mesh and the determination mesh is arbitrary. The number of materials that can be set for the polygons of the display mesh and the number of materials that can be set for the polygons of the determination mesh may both be plural, may be the same, or may be different.

[0172] In addition, in the present embodiment, the number of types of materials set for one voxel is up to two, and the number of types of materials set for one polygon in the display mesh is up to two. According to this, while suppressing the data amount of the voxel data, the information of the materials set in the voxel data can be reflected in the materials of the display mesh. Further, in the present embodiment, the number of types of materials set for the vertices set based on the voxel data is also up to two (see FIG. 16). According to this, for the vertices generated during the process of obtaining the display mesh from the voxel data, two types of materials can be set, so that the information of the materials set in the voxel data can be reflected in the display mesh without loss of material information during the process.

[0173] In another embodiment, the game system 1 may set materials differently for vertices used to generate a display mesh and vertices used to generate a determination mesh with respect to vertices set based on voxel data. For example, the game system 1 may set up to two types of materials for vertices used to generate a display mesh as described above, and may set one type of material for vertices used to generate a determination mesh. For the materials of the polygons of the display mesh, two types of materials may be set in the same manner as above, and as the material of the polygon of the determination mesh, one type of material may be set based on the one type of material set for each vertex of the polygon. When setting one type of material for the vertices used to generate the determination mesh, the material for which the above-described determination value calculated for each material is the largest may be set as the material of the vertex. Also by the above, as in the present embodiment, the number of types of materials set for one polygon in the display mesh can be up to two, and the number of types of materials set for one polygon in the determination mesh can be one. Therefore, it is possible to reflect the material information set in the voxel data in the display mesh, and it is possible to suppress the complication of the processing performed according to the result of the collision determination using the determination mesh.

[0174] As described above, in this embodiment, a display mesh and a determination mesh can be set for one voxel object. However, depending on the game situation, it is not necessary to set both the display mesh and the determination mesh for one voxel object at the same time (for example, it is not necessary to set both in the processing within one frame). For example, the determination mesh may be generated in the range where collision determination is performed in the game space, and may not be generated in the range where collision determination is not performed. As an example, the game system 1 may generate a determination mesh for voxel objects within a predetermined range centered on the player character, and not generate a determination mesh for voxel objects outside the predetermined range, but only generate a display mesh.

[0175] Also, for the display mesh, the game system 1 may store the data related to the generated mesh in the memory, and in the frame after the mesh is generated, use the data without re-executing the process of generating the mesh except for the updated range. According to this, the processing load for generating the display mesh can be reduced. Also, for the determination mesh, the data related to the generated mesh may not be stored in the memory, and the mesh may be sequentially generated as needed (for example, every time collision determination needs to be performed). According to this, the memory area used for generating the mesh can be saved.

[0176] In the above, the method of generating each mesh (that is, the display mesh and the determination mesh) based on the voxel data after the change when the voxel data is changed from the initial state has been described. Note that the above method can also be used when generating each mesh based on the voxel data in the initial state, for example, at the start of the game. However, each mesh based on the voxel data in the initial state does not necessarily need to be generated based on the voxel data in the initial state at the start of the game, and may be prepared in advance before the game starts.

[0177] [Processing Using a Mesh of 2 - 7] Next, a processing example using the mesh generated as described above for the voxel object will be described. In the following, it is assumed that terrain objects such as the ground and walls are voxel objects, and a player character performs an action, and as a result of collision detection, an in - game effect occurs. An example of this case will be described.

[0178] FIG. 26 is a diagram showing an example of a game image representing the movement of a player character on a terrain object. In the example shown in FIG. 26, the material for a part of the polygon in the determination mesh of the terrain object, which is the ground, in region 251 is set to "lava". Note that the materials for the polygons other than region 251 in the determination mesh of the terrain object are set to "rock". In the example shown in FIG. 26, the game system 1 performs a collision determination between the terrain object and the player character 201 using the determination mesh. That is, a collision determination is made as to whether or not the determination mesh of the terrain object and a determination area set for the player character (for example, an area of a predetermined shape set based on the position of the player character) are in contact. And when a collision between the polygon whose material is lava and the player character 201 is determined, as a process for generating an in - game effect, a process of reducing the physical strength of the player character 201 is performed. Also, in the above case, a process of causing the player character 201 to perform a predetermined reaction is performed.

[0179] Note that in this embodiment, as the property information included in the above - mentioned material data, for the lava material, a property of reducing the physical strength of the contacted player character (for example, the property that the temperature is equal to or higher than a predetermined value) is set. The game system 1 generates an in - game effect (in the above example, the reduction of the player character's physical strength) based on the property information corresponding to the material set for the polygon in the determination mesh for which a collision has been determined by the collision determination.

[0180] In addition, when a collision between a polygon whose material is rock and the player character 201 is determined, the process of reducing the physical strength of the player character is not executed. Also, based on the collision, the player character 201 is controlled so that it cannot enter the inside of the polygon. Therefore, the player character can stand on or walk on the polygon. In this way, in the present embodiment, by setting the material for each polygon, the game system 1 can execute different processes according to which part of the voxel object another object has contacted. Also, the content of the process to be executed can be made according to the type of material. In the present embodiment, since the player character can change the terrain object (for example, deform it or change the material), for example, a part of the terrain object that is lava can be erased or the lava can be changed to another material. Therefore, the player can avoid a decrease in the physical strength of the player character due to contact with lava by changing the terrain object.

[0181] Note that the content of the process executed when a collision between a voxel object and another object is determined is arbitrary. For example, when the other object is a moving object such as a player character or an enemy character, the process may be a process of outputting the footsteps of the object or displaying an effect (for example, an effect representing dust or water splashes) at the contact location. At this time, the game system 1 can vary the footsteps or the effects according to the type of material set for the polygon of the part of the voxel object that has been contacted.

[0182] FIG. 27 is a diagram showing an example of a game image representing a state in which a player character extracts a fragment object from a terrain object. As shown in FIG. 27, in the present embodiment, the player can cause the player character 201 to perform an action (referred to as a "pull-out action") of grasping the terrain object 202 by a predetermined operation input and pulling out a part thereof as the fragment object 252 and holding it. The game system 1, as an action in the game caused by the pull-out action, erases a part of the terrain object 202 and generates a fragment object 252.

[0183] When the pull-out action is performed, the game system 1 specifically executes the following processing. That is, when an operation input for causing the player character to perform the pull-out action is performed by the player, the game system 1 causes the player character to perform an action of digging forward and grasping, and performs a collision determination. Then, when a collision between the player character performing the pull-out action and the terrain object is determined, an update range 253 is generated based on the position and orientation of the player character. For example, the update range 253 is generated in a predetermined direction (for example, the front) with respect to the player character. Note that the shape and size of the update range may be determined in advance according to the type of action of the player character. Further, the game system 1 reduces the density of the voxels corresponding to the update range 253. Then, by updating the mesh according to the reduction in the density of the voxels, the terrain object 202 is deformed so that the portion within the update range 253 is erased (see (b) of FIG. 27). In the present embodiment, the density of each voxel corresponding to the update range 253 is reduced, but the voxels to be reduced in density may be at least some of the voxels corresponding to the update range 253.

[0184] Also, in the above, it was assumed that the voxel object corresponding to the update range 253 is unconditionally deformed by the extraction action. However, in other embodiments, the deformation of the voxel object corresponding to the update range 253 may be performed on the condition of the amount of damage set for the voxel. For example, instead of unconditionally deforming the voxel object corresponding to the update range 253, the game system 1 may increase the amount of damage set for the voxel corresponding to the update range 253, and decrease the density in the voxel when the amount of damage exceeds a predetermined value. At this time, the increase amount of damage may be determined according to the action performed on the voxel object.

[0185] In addition, the game system 1 generates a fragment object 252 representing the portion of the terrain object 202 that has been erased. That is, the game system 1 generates the fragment object 252 while having the player character hold it based on the above extraction action. The fragment object 252 may be generated to have a shape corresponding to the portion of the terrain object 202 that has been erased, or may have a predetermined shape. The fragment object 252 may be a voxel object or may not be a voxel object. When the fragment object is a voxel object, a voxel space different from the voxel space of the voxels corresponding to the terrain object 202 or the like is defined for the fragment object 252.

[0186] The game system 1 determines the material of the above-mentioned fragment object 252. The material of the fragment object 252 is determined based on the material set for the polygon within the determination mesh that contacts the update range 253 among the determination meshes of the terrain object 202. The material of the fragment object 252 is determined to be the same as any one of the materials set for the polygons within the determination mesh that contacts the update range 253. According to this, the material of the fragment object 252 can be made the same as the material of the erased part of the terrain object. As is clear from the above description, the fragment object 252 is not actually a part of the terrain object. However, by being generated along with the erasure of a part of the terrain object and having the material of the erased part of the terrain object inherited by the fragment object 252, an impression can be given to the player as if the player character 201 has taken out a part of the terrain object 202 by a pulling-out action.

[0187] In this embodiment, a priority is set for each type of material to be prepared, and the game system 1 determines the material with the highest priority among the materials set for each polygon of the determination mesh within the update range 253 as the material of the fragment object 252. Here, for example, consider a case where the determination mesh within the update range 253 includes a polygon with a material of rock and a polygon with a material of lava. In such a case, if the material of the fragment object 252 is set to lava, there is a possibility that the player character's physical strength will decrease when the player character grips the fragment object 252 by the extraction action (assuming that, as also described in FIG. 26, the material of lava is set to have the property of decreasing the player character's physical strength when contacted). Also, as described above, when the determination mesh within the update range 253 includes polygons with different types of materials set, it is also conceivable that it is difficult for the player to predict what the material of the fragment object 252 will be, and the above-mentioned inconvenience may occur contrary to the player's intention. In contrast, in this embodiment, by setting a priority for the material set as the material of the fragment object, the possibility of the above-mentioned inconvenience occurring can be reduced.

[0188] FIG. 28 is a diagram showing an example of a game image representing a state in which a fragment object is generated when a player character destroys a terrain object. As shown in FIG. 28, in the present embodiment, the player can cause the player character 201 to perform a punch action by a predetermined operation input. Further, as an action in the game caused by the punch action, the game system 1 erases a part of the terrain object 202 and generates a fragment object 255, as in the case of the above punch action. Specifically, the terrain object 202 is deformed as if a part thereof is erased. When the punch action is performed, unlike the above-described extraction action, after the punch action, the fragment object 255 is not held by the player character 201 but is arranged around the position where the punch action is performed (see (b) of FIG. 28). Note that the fragments corresponding to the destruction of the terrain object 202 may not be generated.

[0189] When a punch action is performed, the game system 1 specifically executes the following processing. That is, when an operation input for causing the player character to perform a punch action is performed by the player, the game system 1 causes the player character to perform an action of punching forward and performs a collision determination. Then, when a collision between the player character performing the punch action and the terrain object is determined, an update range 254 is generated based on the position and orientation of the player character. For example, the update range 254 is generated in a predetermined direction (e.g., forward) with respect to the player character. Note that the position, shape, and size of the update range 254 due to the punch action may be the same as or different from the update range 253 due to the extraction action. Then, the game system 1 decreases the density of the voxels corresponding to the update range 254. As a result, similar to the extraction action, also due to the punch action, the terrain object 202 is deformed such that the portion within the update range 254 is erased (see (b) of FIG. 28). Note that, similar to the extraction action, for the punch action as well, instead of unconditionally deforming the voxel object corresponding to the update range 254, the game system 1 may increase the amount of damage set for the voxels within the update range 254 according to the punch action, and decrease the density of the voxels when the amount of damage exceeds a predetermined value. Also, the voxels whose density is to be decreased by the punch action may be at least some of the voxels corresponding to the update range 254.

[0190] In addition, the game system 1 generates a fragment object 255 corresponding to the portion of the terrain object 202 that has been erased. That is, the game system 1 generates the fragment object 255 without giving it to the player character based on the above punch action (for example, in a state where it is arranged around the position where the punch action was performed). The fragment object 255 may be generated to have a shape corresponding to the portion of the terrain object 202 that has been erased, or may have a predetermined shape. The fragment object 255 may be a voxel object or may not be a voxel object.

[0191] The game system 1 determines the material of the above fragment object 255. The material of the fragment object 255 is determined based on the material set for the polygon within the determination mesh that contacts the update range 254 among the determination meshes of the terrain object 202. The material of the fragment object 255 is determined to be the same as any one of the materials set for the polygons within the determination mesh that contacts the update range 254. According to this, the material of the fragment object 255 can be made the same as the material of the erased portion of the terrain object. Also, when a part of the terrain object is erased and the fragment object 255 is generated, and the material of the erased portion of the terrain object is inherited by the fragment object 255, it is possible to give the player an impression that a part of the terrain object destroyed by the punch action of the player character has occurred as a fragment object.

[0192] In this embodiment, the material of the fragment object 255 is determined to be the material with the largest degree of decrease in density in the voxels among the materials set for the polygons within the determination mesh that contacts the update range 254. According to this, it is possible to generate a fragment object that more accurately reflects the material composition of the portion of the terrain object erased by the punch action.

[0193] The method for determining the material of the fragment object generated by the above-described extraction action or punch action is arbitrary. For example, the method for determining the material of the fragment object may be the same for both the extraction action and the punch action. Also, for example, among the materials set for each polygon of the determination mesh within the update range, the material set for the most polygons may be determined as the material of the fragment object. Also, for example, among the polygons of the determination mesh within the update range, the material set for a polygon that satisfies a predetermined condition (for example, a polygon at a position in contact with the hand of the player character performing the extraction action or punch action) may be determined as the material of the fragment object. Also, in other embodiments, a plurality of types of materials may be set for the fragment object.

[0194] In this embodiment, the player can cause the player character to perform an action of throwing the fragment object 252 or 255 generated as described above (hereinafter referred to as the "throwing action"). Note that the player can cause the player character to perform an action of holding a fragment object that is generated in response to a punch action and placed on the ground by a predetermined operation input. By the above-described extraction action or the action of holding the fragment object after the above-described punch action, the player character is in a state of holding the fragment object. In this state, the game system 1 causes the player character to perform an action of releasing the held fragment object in a predetermined direction as a throwing action according to an operation input by the player.

[0195] FIG. 29 is a diagram showing an example of a game image in a scene where the throwing direction is determined in a state where a throwing action by the player character is possible and the player character is in a stance for throwing. As shown in FIG. 29, in a state where the player character 201 has the fragment object 261, the player character 201 can perform a throwing action. In this state, as shown in FIG. 29, the game system 1 displays the aiming image 262 and the object information image 263 over the image showing the game space as a process for generating an action in the game.

[0196] The aiming image 262 indicates the direction in which the fragment object is released by the throwing action (also referred to as the aim direction). That is, in response to the player performing an operation input for performing a throwing action, the game system 1 moves the fragment object 261 from the position of the player character 201 toward the position in the virtual space indicated by the aiming image 262. Note that the aim direction is controlled based on the operation input by the player. For example, the game system 1 may change the aim direction in response to an operation input for changing the direction of the virtual camera. Specifically, the game system 1 controls the virtual camera in response to an operation input so as to rotate and move around the player character while maintaining the state where the player character is included in the field of view, and controls the aim direction so as to be in the direction corresponding to the line-of-sight direction of the virtual camera. At this time, the aiming image 262 indicating the position where the straight line extending in the aim direction from the position of the player character intersects the terrain object 253 is displayed. Specifically, the game system 1 performs a collision determination between the aim direction (that is, the straight line extending in the aim direction) and the determination mesh of the terrain object 253, and when a collision is determined, the aiming image 262 is displayed. The aiming image 262 is arranged so as to indicate the position of the polygon that intersects the straight line extending in the aim direction among the determination meshes.

[0197] When the player character performs a throwing action using the aiming image 262 described above, the player can be presented with the position where the fragment object contacts the voxel object. This makes it easier for the player to perform the throwing action operation. Note that the specific control method for the aiming direction and the aiming image 262 is arbitrary, and a conventional method may be used. For example, in other embodiments, in the state where the aiming image 262 is displayed, the aiming image 262 may be displayed in a first-person perspective game image where the player character is not displayed.

[0198] In a state where the player character is in a position to throw a fragment object, in response to a predetermined operation input by the player, a throwing action of throwing the fragment object in the aiming direction is performed.

[0199] The object information image 263 shows information about the terrain object 253 at the position indicated by the aiming image 262. In the present embodiment, the object information image 263 shows the name of the material (rock in the example shown in FIG. 29) set for the polygon of the determination mesh at the position indicated by the aiming image 262. This allows the player to be presented with the material of the voxel object that the fragment object released by the throwing action contacts. Also, the object information image 263 shows information about the properties of the material (here, hardness). This allows the player to be presented with the properties of the voxel object that the fragment object released by the throwing action contacts. Note that the content shown by the object information image 263 is arbitrary. For example, in other embodiments, the object information image 263 may show any property related to the material set for the polygon at the position indicated by the aiming image 262, or may show the state of the polygon (for example, the amount of damage described above). In the present embodiment, since there is one type of material for the polygon of the determination mesh, the material corresponding to the aiming position is specified as one. Therefore, it is suitable for displaying information about the material.

[0200] In this embodiment, in response to the fragmented object released by a throwing action being determined to have contacted the voxel object as a result of collision determination, the game system 1 makes a change to the voxel object as an action within the game. FIG. 30 is a diagram showing an example of a game image after a change has been made to the terrain object 253 due to the fragmented object 261 contacting the terrain object 253 shown in FIG. 29. In the example shown in FIG. 30, the terrain object 253 is deformed so as to have a shape such that the fragmented object is attached to the contact position between the fragmented object and the terrain object 253. Specifically, the game system 1 generates an update range so as to include the contact position, and deforms the terrain object 253 into the above shape by increasing the density of the voxels within the update range. For example, the update range may be set to a shape corresponding to the shape of the fragmented object, and the terrain object 253 may be deformed so that the inside of the update range is within the terrain object 253. As described above, in the example shown in FIG. 30, the shape is such that an additional portion 265 is added to the terrain object before deformation. Note that in the example shown in FIG. 30, the fragmented object is erased in response to contacting the terrain object 253.

[0201]

[0202] Also, the material of the polygon in the additional portion 265 is determined based on the material of the fragmented object that has contacted the terrain object 253. Specifically, the game system 1 sets the material of the voxels within the update range to be the material of the fragmented object. Then, the materials of the display mesh and the determination mesh are determined based on the material of the voxels. According to this, since the appearance of the attached additional portion 265 can be made the same as the appearance of the fragmented object, (although the terrain object 253 is actually deformed as described above), it becomes easier for the player to get the impression that the fragmented object is attached to the terrain object 253.In the example shown in FIG. 30, the change applied to the voxel object in response to the fragment object contacting the voxel object was a deformation that added an additional part to the voxel object, but the change applied to the voxel object is not limited to this. The above change may change the density of the voxels or may change the material. For example, if the fragment object has the property of exploding, the fragment object may explode in response to contacting the voxel object, and at this time, the voxel object may be deformed as if a part of the voxel object has been erased. Specifically, the game system 1 sets an update range to include the contact position and decreases the density of the voxels within the update range. Also, for example, when the material of the voxel object is lava and the material of the fragment object is ice, the material of the voxel object may be changed in response to the fragment object contacting it. Specifically, the game system 1 sets an update range including the contact position and may change the material that is lava among the materials of the voxels within the update range to obsidian or rock. According to this, it is possible to represent a situation where a lava object is cooled by an ice object and becomes obsidian or rock.

[0203] The content of the above change may be determined based on the material of the voxel object, based on the material of the fragment object, or based on a combination of the material of the voxel object and the material of the fragment object. According to this, various changes can be caused to the voxel object.

[0204] Also, the game system 1 may determine whether to perform the above-described change based on the material of the voxel object, based on the material of the fragment object, or based on a combination of the material of the voxel object and the material of the fragment object. For example, when a fragment object with a material of rock contacts a voxel object with a material of rock, the game system 1 makes the change as shown in FIG. 30, while when a fragment object with a material of rock contacts a voxel object with a material of iron, the game system 1 may not make the change as shown in FIG. 30.

[0205] In this embodiment, as described above, one type of material is set for the polygon of the determination mesh and the fragment object. Here, if multiple types of materials are set for at least either the polygon of the determination mesh or the fragment object, it becomes difficult to determine the content of the change added to the voxel object according to the types of the materials of both when the determination mesh and the fragment object come into contact. On the other hand, in this embodiment, since the materials of the determination mesh and the fragment object determined to be in contact by the collision determination are each one type, it becomes easy to determine the content of the change added to the voxel object.

[0206] [3. Specific Example of Processing in Game System] Next, with reference to FIGS. 31 and 32, a specific example of the information processing in the game system 1 will be described.

[0207] FIG. 31 is a diagram showing an example of various data used for information processing in the game system 1. Each data shown in FIG. 31 is stored in a memory accessible by the main body device 2 (for example, a flash memory 84, a DRAM 85, and / or a memory card or the like mounted on the slot 23). As shown in FIG. 31, the game system 1 stores a game program. The game program is for executing the game processing in the present embodiment (specifically, the game processing shown in FIG. 32). Note that the game program includes the above-described material data (see FIG. 12). Further, the above memory stores the above-described voxel data (see FIG. 11), update range data, mesh data, object data, etc. (see FIG. 31).

[0208] The update range data is data indicating the above-described update range. In the present embodiment, the update range is represented by the above-described SDF.

[0209] The mesh data includes various data related to the mesh of the voxel object. As shown in FIG. 31, in the present embodiment, the mesh data includes SVO data, display mesh data, and determination mesh data. The SVO data is data that holds each vertex calculated from the voxel data in the above-described SVO structure. Note that in the present embodiment, the SVO data includes, in addition to data indicating the position of each vertex, data indicating the material set for each vertex (for example, data indicating the ID of the material). The display mesh data includes various data related to the display mesh. Specifically, the display mesh data includes data indicating each vertex of the display mesh and data indicating the material set for each vertex (for example, data indicating the ID of the material). The determination mesh data includes various data related to the determination mesh. Specifically, the determination mesh data includes data indicating each vertex of the determination mesh and data indicating the material set for each vertex (for example, data indicating the ID of the material).

[0210] Object data includes various data related to objects other than voxel objects (e.g., player characters, fragment objects, etc.). Object data is stored for each object that appears in the game space. Object data includes, for example, data indicating the position, speed, and state of the object.

[0211] FIG. 32 is a flowchart showing an example of the flow of game processing executed by the game system 1. The execution of the game processing is started, for example, in response to the start of the game according to the player's instruction during the execution of the above game program. Note that the processing loop consisting of a series of processes in steps S1 to S14 is executed in one cycle per frame.

[0212] In the present embodiment, the processor 81 of the main body device 2 executes the processing of each step shown in FIG. 32 by executing the above game program stored in the game system 1. However, in other embodiments, some of the processing of each step may be executed by a processor (e.g., a dedicated circuit, etc.) different from the processor 81. Further, when the game system 1 can communicate with another information processing device (e.g., a server), a part of the processing of each step shown in FIG. 32 may be executed in the other information processing device. Also, the processing of each step shown in FIG. 32 is merely an example, and if the same result can be obtained, the processing order of each step may be changed, or another process may be executed in addition to (or instead of) the processing of each step.

[0213] Further, the processor 81 executes the processing of each step shown in FIG. 32 using a memory (e.g., DRAM 85). That is, the processor 81 stores the information (in other words, data) obtained by each processing step in the memory, and when using the information in subsequent processing steps, reads out the information from the memory and uses it.

[0214] In step S1 shown in FIG. 32, the processor 81 acquires the operation data indicating the operation input by the player. That is, the processor 81 acquires the operation data received from each controller via the controller communication unit 83 and / or each of the terminals 17 and 21. The process of step S2 is executed after step S1.

[0215] In step S2, the processor 81 designates, as a processing target, any one of the objects in the game space that need to be processed and for which the processing has not been completed, and executes a process of calculating the speed and a process of reflecting the result of contact between the objects in the previous frame for the designated object. The speed of the object is used to calculate the position of the object in the current frame in the process of step S12 described later. For example, when the designated object is the player character, the speed of the player character is calculated based on the operation data acquired in step S1. Also, when the designated object is an object not operated by the player (for example, a fragment object), the speed of the object is calculated based on a rule predetermined in the game program. For example, the speed of a fragment object is set to 0 when it is placed on a terrain object and not moving, is set to the same as the speed of the player character when held by the player character, and is set to the speed of moving in the above-mentioned aiming direction with a magnitude determined by the above rule when released by a throwing action by the player character. Specifically, the speed of the object is calculated based on virtual physical calculations including the interaction between the objects. For example, interactions such as repulsion due to collision between objects, friction due to contact, falling due to virtual gravity, and deceleration due to virtual air resistance are reflected in the speed determination.

[0216] In addition, for the process of reflecting the result of contact between objects in the previous frame, when it is determined in the collision determination (step S11) in the previous frame that the objects are in contact, the process includes applying the influence of contact to the object. The above process is, for example, the following process. · When it is determined that the player character has come into contact with the lava terrain object in the previous frame, the process of reducing the physical strength of the player character · When it is determined that the player character has come into contact with the terrain object by a pulling action or a punch action in the previous frame, the process of generating a fragment object · When it is determined that the fragment object has come into contact with the rock terrain object in the previous frame, the process of disappearing the fragment object When the state regarding the object is changed in the process of step S2 above, the processor 81 updates the object data stored in the memory regarding the object so as to indicate the changed content. The process of step S3 is executed next to step S2.

[0217] In step S3, the processor 81 determines whether an update event for updating the voxel object has occurred due to the object specified in step S2. For example, the determination in step S3 is made based on the result of the collision determination (step S11) in the previous frame. For example, when it is determined that the player character has come into contact with the terrain object by a pulling action or a punch action in the previous frame, it is determined that an update event of deleting a part of the terrain object (see FIGS. 27 and 28) has occurred. Also, for example, when it is determined that the fragment object has come into contact with the rock terrain object in the previous frame, it is determined that an update event of increasing the volume of the terrain object (see FIG. 30) has occurred. If the determination result of step S3 is affirmative, the process of step S4 is executed. On the other hand, if the determination result of step S3 is negative, the process of step S6 is executed.

[0218] In step S4, the processor 81 sets an update range for updating the voxel object in the game space. For example, the specific content of the update range (i.e., position, shape, and size) is associated with each type of update event in the game program. The update range set in step S4 is set to be associated with the content related to the type of update event determined to occur in step S3. The processor 81 stores data indicating the set update range in the memory as update range data. The process of step S5 is executed after step S4.

[0219] In step S5, the processor 81 makes changes according to the update event for the voxels corresponding to the update range set in step S4. For example, when deforming the voxel object within the update range as if it were erased or deforming it as if a voxel object were added within the update range, the voxel data stored in the memory is updated so as to change the density of the voxels corresponding to the update range (see the above [2-2. Update of voxel data]). Also, for example, when changing the material of the voxel object within the update range, the voxel data stored in the memory is updated so as to update the first and second material IDs and the material mixing ratio of the voxels corresponding to the update range. The process of step S6 is executed after step S5.

[0220] In step S6, the processor 81 determines whether the processing of the above steps S2 to S5 has been completed for all the objects that require processing. If the determination result in step S6 is affirmative, the process of step S7 is executed. On the other hand, if the determination result in step S6 is negative, the process of step S2 is executed again.

[0221] In step S7, the processor 81 updates the vertices of the voxel object in the game space. That is, when the voxel data is updated in the process of step S5, new vertices are calculated based on the updated voxel data. Note that the positions of the new vertices are calculated according to the method described in the above [2-3. Calculation of Vertices]. Also, the materials of the new vertices are calculated according to the method described in the above [2-4. Determination of Vertex Materials]. The process of step S8 is executed after step S7.

[0222] In step S8, the processor 81 performs vertex simplification. That is, the processor 81 simplifies each vertex updated by the process of step S7 according to the method described in the above [2-5. Vertex Simplification]. The SVO data stored in the memory is updated to indicate each vertex obtained by the processes of steps S7 and S8 above. Therefore, the SVO data is updated by the processes of steps S7 and S8. Note that the processes of steps S7 and S8 do not necessarily recalculate the vertices for the entire voxel data, and may be executed only for the parts where the contents of the voxels are changed in the process of step S5. The process of step S9 is executed after step S8.

[0223] In step S9, the processor 81 updates the display mesh of the voxel object based on the SVO data stored in the memory. Note that the positions of the vertices of the display mesh and the materials of the polygons of the display mesh (i.e., the materials set for the vertices of the polygons) are calculated according to the methods described in the above [2-6. Generation of Mesh] and [2-6-1. Determination of Materials for Display Mesh]. The processor 81 updates the display mesh data stored in the memory so as to indicate the positions and materials of the vertices of the updated display mesh. The process of step S10 is executed after step S9. Note that the processor 81 may start the processes after step S10 and execute them in parallel without waiting for the completion of step S9. In that case, step S9 needs to be completed before the start of step S13.

[0224] In step S10, the processor 81 updates the determination mesh of the voxel object based on the SVO data stored in the memory. Note that the positions of the vertices of the determination mesh and the materials of the polygons of the determination mesh (i.e., the materials set for the vertices of the polygons) are calculated according to the methods described in the above [2-6. Generation of Mesh] and [2-6-2. Determination of Materials for Determination Mesh]. The processor 81 updates the determination mesh data stored in the memory so as to indicate the positions and materials of the vertices of the updated determination mesh. The process of step S11 is executed after step S10.

[0225] In the example shown in FIG. 32, the generation process of the determination mesh (step S10) is executed every frame. However, the generation process of the determination mesh does not necessarily have to be executed every frame. For example, when the collision determination process in step S11 is executed only in frames that satisfy a predetermined condition, the processor 81 may execute the generation process of the determination mesh in the frames in which the collision determination in step S11 is performed. Further, the processor 81 may execute the generation process of the determination mesh for the voxels within the area in the game space where the collision determination in step S11 is performed. For example, in a situation where there are no objects to be collided with other than the voxel objects around the player character in the game space (that is, a situation where only the collision determination between the player character and the surrounding voxel objects needs to be performed), the processor 81 may execute the generation process of the determination mesh for the voxels within a predetermined range based on the player character.

[0226] In step S11, the processor 81 performs a collision determination for each object in the game space based on the determination mesh data and the object data stored in the memory. That is, for the voxel object, the processor 81 uses the determination mesh, and for an object that is not a voxel object, the processor 81 uses a determination area of a predetermined shape set for the object to perform the collision determination. In the present embodiment, the collision determination in step S11 is performed in consideration of the speed calculated in step S2 above. That is, the processor 81 performs the collision determination using the position when moving at the above speed as the position of each object.

[0227] In the present embodiment, for example, the presence or absence of the following contacts is determined by the collision determination in step S11. · Contact between a player character performing a movement, a punch action, or a pull-out action and a terrain object · Contact between a character performing an action of lifting (a fragment object) and the fragment object · Contact between the terrain object and the straight line extending in the aiming direction from the position of the player character · Contact between the fragment object released by the throwing action of the player character and the terrain object If it is determined in the collision determination in step S11 that the objects are in contact with each other, then in the process of step S2 in the next frame, a process reflecting the result of the contact between the objects is executed, or in the process of step S3 in the next frame, it is determined that an update event has occurred. The process of step S12 is executed after step S11.

[0228] In step S12, the processor 81 controls the operations of the respective objects in the game space. For example, for the player character, the processor 81 performs control to cause the player character to move and perform various actions based on the operation data acquired in step S1. When a predetermined action occurs, a region for collision determination corresponding to the action is generated in the game space. Also, for example, the fragment object is controlled to move in the above-described aiming direction in response to being released by the throwing action of the player character. In one execution of the process of step S12, the processor 81 controls each object so as to advance the operation for one frame for an operation (for example, an action by the player character) performed over a plurality of frames. By repeatedly executing the process of step S12 over a plurality of frames, each object performs a series of operations related to movement and various actions. Also, the position of the object is basically determined to be the position after moving at the speed calculated in step S2 above. However, if it is determined by the collision determination in step S11 that the object comes into contact with another object and the movement is obstructed by the other object in contact, the position of the object is determined not to change. The object data stored in the memory is updated to indicate the object after the control in step S12. The process of step S13 is executed after step S12.

[0229] In step S13, the processor 81 generates a game image. That is, the processor 81 generates a game image by performing rendering based on a virtual camera for each polygon of the display mesh of the voxel object and each polygon of the object other than the voxel object. Note that each polygon of the display mesh is rendered using rendering settings such as a texture corresponding to the material set for the polygon according to the method described in the above [2-6-1. Determination of the material of the display mesh]. Also, in the present embodiment, when the player character is in a state where a throwing action is possible, the processor 81 generates a game image so as to include the above-described aiming image and object information image (see FIG. 29). The game image generated in step S13 is output to the display device and displayed at a cycle of once per frame.

[0230] In step S14, the processor 81 determines whether to end the game. For example, when a player performs a predetermined operation input for ending the game, the processor 81 determines to end the game. If the determination result in step S14 is negative, the process of step S1 is executed again. Thereafter, the series of processes of steps S1 to S14 are repeatedly executed until it is determined in step S14 to end the game. On the other hand, if the determination result in step S14 is positive, the processor 81 ends the game process shown in FIG. 32.

[0231] [4. Operational Effects and Modification Examples of the Present Embodiment] According to the above embodiment, the number of vertices of the mesh can be effectively reduced by vertex simplification. As a result, the load of processing related to the mesh, such as rendering processing, can be reduced. Further, according to the above embodiment, as a simplification condition, by using a condition including at least that the total number of types of materials of each vertex included in the vertex group is equal to or less than a certain number, it is possible to suppress a large loss of vertex material information before simplification and reduce the number of vertices. For example, it is possible to reduce the number of vertices while reducing the possibility that the appearance of the polygon will change significantly due to simplification.

[0232] In the above embodiment, simplification is performed on the vertices of the mesh generated based on voxel data, but the target for which simplification is performed may be the vertices of the mesh generated by any method. For example, in other embodiments, the mesh for which vertex simplification is performed may be generated without using voxel data, or may be prepared in advance in a game program. Note that the method for setting the material of the vertex before simplification for the mesh generated without using voxel data is arbitrary.

[0233] Further, the mesh for which vertex simplification is performed may be a mesh used only for display, or may be a mesh used for other purposes than display. In the above embodiment, two types of meshes, a display mesh and a determination mesh, are used, and simplification is performed on both meshes. In contrast, in other embodiments, one type of mesh used for both display and collision determination may be generated, and simplification may be performed on such a mesh. Further, when the above two types of meshes are used, simplification may be performed on both meshes as in the above embodiment, or simplification may be performed on either one of the meshes.

[0234] In addition, in the above-described embodiment, when processing is executed using data (in the sense including programs) in a certain information processing apparatus, a part of the data necessary for the processing may be transmitted from another information processing apparatus different from the certain information processing apparatus. At this time, the certain information processing apparatus may execute the above-described processing using the data received from the other information processing apparatus and the data stored in itself.

[0235] In addition, in other embodiments, the information processing system may not include a part of the configuration in the above-described embodiment, or may not execute a part of the processing executed in the above-described embodiment. For example, in order for the information processing system to exhibit some specific effects in the above-described embodiment, it may include a configuration for achieving the effects and execute processing for achieving the effects, and may not include other configurations or execute other processing.

Industrial Applicability

[0236] The above-described embodiment can be used, for example, as a game system or a game program for the purpose of effectively reducing the number of vertices of an object mesh, etc.

Explanation of Signs

[0237] 1 Game system 2 Main body device 81 Processor 201 Player character 202 Terrain object 203, 253, 254 Update range 211~218 Voxels 262 Aiming image 263 Object information image

Claims

1. In a computer of an information processing apparatus, for a plurality of vertices that constitute a mesh defined in a virtual space and each of which has at least one type of material set thereon, for each of a plurality of vertex groups each including a plurality of adjacent vertices, when a simplification condition including at least that the total number of types of materials of the vertices included in the vertex group is equal to or less than a first number is satisfied, simplify by replacing the plurality of vertices of the vertex group with one vertex having the types of materials equal to the total number, A game program that causes the mesh based on the vertices reflecting the simplification to be drawn based on a drawing setting based on the material of each vertex.

2. Further in the computer, Based on voxel data defined in the virtual space, for each of a plurality of voxels, a density indicating the degree to which the space defined by the voxel is virtually occupied by the content, and a material indicating the type of the content, and voxel data in which at least a material that can be set up to a second number is set, For a portion where a voxel having the density of a setting indicating existence and a voxel having the density of a setting indicating non-existence are adjacent, set vertices at coordinates based on the positions and the density of a plurality of surrounding voxels, and for each of the vertices, select the materials up to the first number from the materials included in the voxel data of the plurality of surrounding voxels and set them as the material of the vertex to determine the vertex, When generating the mesh in the virtual space, perform the simplification on all the vertices determined based on the voxel data, The game program according to claim 1, wherein the mesh is generated based on the vertices reflecting the simplification.

3. Further in the computer, Based on game processing, cause at least any one of the voxels included in the voxel data to be updated such that at least either the density or the material changes, When the update is performed, further perform setting of the coordinates of the vertices and the simplification on the vertices in a range including the portion where the update is performed, The game program according to claim 2, wherein the mesh is updated based on the vertices reflecting the simplification.

4. In the computer, For each of the vertices, for the material included in the voxel data of the plurality of voxels in the vicinity, calculate a priority parameter for each material based on the voxel data, and based on the priority parameter, select the materials up to the first number with high priority and determine them as the material of the vertex. For each polygon, select the materials up to the first number among the materials set for the vertices included in the polygon and determine them as the material of the polygon. For each polygon, based on the materials of all the vertices constituting the polygon. When the number of the materials is less than or equal to the first number, set the material as the material of the polygon. When the number of the materials exceeds the first number, select the first number with high priority based on the priority parameter of each vertex and determine it as the material of the polygon. The game program according to claim 3.

5. The computer further Drawing setting information including at least information on a texture set for a material, and based on the drawing setting information corresponding to each material set for each polygon included in the mesh, at each position of each vertex, with a blend rate corresponding to the priority parameter of the vertex, between vertices, by mapping that blends a plurality of textures with an interpolation blend rate obtained by interpolating the blend rates of the respective vertices, cause the polygon to be drawn. The game program according to claim 4.

6. The computer further For each polygon of the mesh, by selecting the materials up to the first number among the materials set for the vertices included in the polygon and determining them as the material of the polygon, generate and update the material of the polygon. Based on the coordinates of the vertices of the mesh and the texture corresponding to the material of the polygon, cause the mesh to be drawn. The game program according to claim 1.

7. The simplified condition further includes that a vertex where material reduction is performed to set the material of the first number based on a material exceeding the first number, or a vertex simplified based on the vertex where the material reduction is performed is not included in the vertex group. The game program according to any one of claims 1 to 6.

8. The simplified condition further includes that the shape error between the mesh before simplification and the mesh after simplification is within a predetermined range. The game program according to any one of claims 1 to 6.

9. The first number and the second number are 2. The game program according to any one of claims 1 to 6.

10. The computer further corresponding to the voxel data, determine a determination mesh used for collision determination in game processing based on at least the density included in the voxel data for the vertex coordinates of the determination mesh, determine the material of the determination mesh based on at least the material included in the voxel data, and further generate or update by performing the simplification. The game program according to any one of claims 1 to 6.

11. The simplified condition further includes that the shape error between the mesh before simplification and the mesh after simplification is within a predetermined range, and the simplified condition for the determination mesh uses a range including an error larger than the error in the simplified condition of the mesh as the predetermined range. The game program according to claim 10.

12. For a plurality of vertices that are vertices constituting a mesh defined in a virtual space and each have at least one type of material set, for each of a plurality of vertex groups including a plurality of adjacent vertices, when a simplified condition including at least that the total number of types of materials of each vertex included in the vertex group is equal to or less than a first number is satisfied, perform simplification to replace the plurality of vertices of the vertex group with one vertex having the number of types of materials set, draw the mesh based on the vertices after the simplification is reflected based on the drawing settings based on the materials of the respective vertices. An information processing system.

13. The information processing system further Voxel data defined in the virtual space, for each of a plurality of voxels, a density indicating the degree to which the space defined by the voxel is virtually occupied by the content, and a material indicating the type of the content, the material being settable up to a second number, based on the voxel data in which at least the material is set, For a portion where a voxel having the density of the setting indicating existence and a voxel having the density of the setting indicating non-existence are adjacent, vertices are set at coordinates based on the positions and the density of a plurality of surrounding voxels, and for each of the vertices, among the materials included in the voxel data of the plurality of surrounding voxels, the materials up to the first number are selected and set as the material of the vertex to determine the vertex, When generating the mesh in the virtual space, performing the simplification on all of the vertices determined based on the voxel data, The information processing system according to claim 12, generating the mesh based on the vertices reflecting the simplification.

14. The information processing system further, Based on game processing, for at least any one of the voxels included in the voxel data, performing an update in which at least either the density or the material changes, When the update is performed, further performing setting of the coordinates of the vertices and the simplification on the vertices in a range including the location where the update is performed, The information processing system according to claim 13, updating the mesh based on the vertices reflecting the simplification.

15. The information processing system, For each of the vertices, for the materials included in the voxel data of the plurality of surrounding voxels, calculating a priority parameter for each material based on the voxel data, and based on the priority parameter, selecting the materials up to the first number with higher priority and determining them as the material of the vertex, For each polygon, among the materials set for the vertices included in the polygon, selecting the materials up to the first number and determining them as the material of the polygon, For each polygon, based on the materials of all the vertices constituting the polygon, When the number of the materials is less than or equal to the first number, setting the material as the material of the polygon, The information processing system according to claim 14, wherein when the number of the materials exceeds the first number, the first number with a higher priority is selected based on the priority parameter of each vertex and determined as the material of the polygon.

16. The information processing system further is drawing setting information including at least information on a texture set for a material, and based on the drawing setting information corresponding to each of the materials set for each polygon included in the mesh, at each position of each vertex, with a blend rate corresponding to the priority parameter of the vertex, between the vertices, by a mapping that blends a plurality of textures with an interpolation blend rate obtained by interpolating the blend rates of the respective vertices, the polygon is drawn. The information processing system according to claim 15.

17. The information processing system further generates and updates the material of the polygon by selecting, for each polygon of the mesh, the materials up to the first number among the materials set for the vertices included in the polygon and determining them as the material of the polygon, draws the mesh based on the coordinates of the vertices of the mesh and the texture corresponding to the material of the polygon. The information processing system according to claim 12.

18. An information processing apparatus including a processor, wherein the processor for a plurality of vertices that are vertices constituting a mesh defined in a virtual space and each having at least one type of material set thereon, for each of a plurality of vertex groups including a plurality of adjacent vertices, when a simplification condition including at least that the total number of types of materials of the respective vertices included in the vertex group is equal to or less than a first number is satisfied, simplifies by replacing the plurality of vertices of the vertex group with one vertex having the total number of types of materials set thereon, draws the mesh based on the vertices after the simplification based on a drawing setting based on the material of each vertex. An information processing apparatus.

19. In an information processing system, for a plurality of vertices that are vertices constituting a mesh defined in a virtual space and each having at least one type of material set thereon, For each of a plurality of vertex groups each including a plurality of adjacent vertices, when a simplification condition including at least that the total number of types of materials of each vertex included in the vertex group is equal to or less than a first number is satisfied, simplify the plurality of vertices of the vertex group by replacing them with one vertex set with materials of the total number of types. A game processing method of rendering the mesh based on the vertices reflecting the simplification based on a rendering setting based on the material of each vertex.

20. The information processing system further, Based on voxel data defined in the virtual space, for each of a plurality of voxels, at least a density indicating the degree to which the space defined by the voxel is virtually occupied by the content, and a material indicating the type of the content, where the material can be set up to a second number. For a portion where a voxel having the density of the setting indicating existence and a voxel having the density of the setting indicating non-existence are adjacent, set vertices at coordinates based on the positions and the density of a plurality of surrounding voxels, and for each vertex, select up to the first number of the materials included in the voxel data of the plurality of surrounding voxels and set it as the material of the vertex to determine the vertex. When generating the mesh in the virtual space, perform the simplification on all the vertices determined based on the voxel data. The game processing method according to claim 19, wherein the mesh is generated based on the vertices reflecting the simplification.

21. The information processing system further, Based on game processing, update at least any one of the voxels included in the voxel data such that at least one of the density and the material changes. When the update is performed, further perform setting of the coordinates and the simplification of the vertices in a range including the location where the update is performed. The game processing method according to claim 20, wherein the mesh is updated based on the vertices reflecting the simplification.

22. In the information processing system, For each of the vertices, for the material included in the voxel data of the plurality of voxels in the vicinity, calculate a priority parameter for each material based on the voxel data, and based on the priority parameter, select the materials up to the first number with high priority and determine them as the material of the vertex. For each polygon, select the materials up to the first number among the materials set for the vertices included in the polygon and determine them as the material of the polygon. For each polygon, based on the materials of all the vertices constituting the polygon. When the number of the materials is less than or equal to the first number, set the material as the material of the polygon. When the number of the materials exceeds the first number, select the first number with high priority based on the priority parameter of each vertex and determine it as the material of the polygon. The game processing method according to claim 21.

23. The information processing system further includes drawing setting information including at least information on a texture set for a material, and based on the drawing setting information corresponding to each material set for each polygon included in the mesh, at each position of each vertex, with a blend rate corresponding to the priority parameter of the vertex, between the vertices, a plurality of textures are blended by a mapping that interpolates the blend rate of each vertex with an interpolation blend rate, and the polygon is drawn. The game processing method according to claim 22.

24. The information processing system further includes For each polygon of the mesh, by selecting the materials up to the first number among the materials set for the vertices included in the polygon and determining them as the material of the polygon, generate and update the material of the polygon. Based on the coordinates of the vertices of the mesh and the texture corresponding to the material of the polygon, draw the mesh. The game processing method according to claim 19.

25. The simplified condition further includes that a vertex where material reduction is performed to set the material of the first number based on a material exceeding the first number, or a vertex simplified based on the vertex where the material reduction is performed, is not included in the vertex group. The game processing method according to any one of claims 19 to 24.

26. The simplified condition further includes that the shape error between the mesh before simplification and the mesh after simplification is within a predetermined range. The game processing method according to any one of claims 19 to 24.

27. The first number and the second number are 2. The game processing method according to any one of claims 19 to 24.

28. The information processing system further includes a determination mesh corresponding to the voxel data and used for collision determination in game processing, and determines the vertex coordinates of the determination mesh based on at least the density included in the voxel data, determines the material of the determination mesh based on at least the material included in the voxel data, and further generates or updates the determination mesh by performing the simplification. The game processing method according to any one of claims 19 to 24.

29. The simplified condition further includes that the shape error between the mesh before simplification and the mesh after simplification is within a predetermined range, and the simplified condition for the determination mesh uses a range including an error larger than the error in the simplified condition of the mesh as the predetermined range. The game processing method according to claim 28.

Images