Slicing method and system, computer equipment, storage medium and product

Abstract

The invention discloses a slicing method and system, computer equipment, a computer readable storage medium and a computer program product, and the slicing method comprises the following steps: creating a plurality of continuous layers capable of completely wrapping an implicit expression model; and selecting any number of continuous layers from the plurality of layers to form a subspace so as to carry out step-by-step gridding on the subspace, which comprises the following steps of: recursively executing to respectively determine a value interval of implicit expression of each subgrid of the current level so as to carry out next-level gridding on the subgrids of which the value interval comprises a threshold interval, each sub-grid of the current level is a single-layer grid meeting the corresponding layer resolution; and selecting a sub-grid of which the value interval of the implicit expression comprises the threshold interval from the single-layer grid meeting the corresponding layer resolution as a key grid, and filling an output value of the implicit expression of at least one representative point in the key grid, so as to determine the slice contour of each selected layer.

Description

Technical Field

[0001] The present application relates to the field of 3D printing technology, and specifically to a slicing method and system, a computer device, a computer-readable storage medium, and a computer program product. Background Art

[0002] In the field of 3D printing, the STL (Standard Triangulation Language) file required for 3D printing equipment is obtained by slicing the 3D model. Currently, most slicing methods are to slice the triangular mesh model. When the 3D model is an implicit model obtained by implicit modeling, it is usually necessary to convert the implicit model into a triangular mesh model before slicing. However, the process of converting the implicit model into a triangular mesh model takes a lot of time, which leads to low slicing efficiency of the implicit model.

[0003] In view of this, how to efficiently slice the implicit model is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned related technologies, the purpose of the present application is to provide a slicing method and system, a computer device, a computer-readable storage medium and a computer program product to overcome the technical problem of how to efficiently slice the implicit model existing in the above-mentioned related technologies.

[0005] To achieve the above-mentioned purpose and other related purposes, the first aspect disclosed in the present application discloses a slicing method, which includes the following steps: creating a plurality of continuous layers that can completely wrap an implicit expression model; wherein the plurality of layers are respectively configured with layer resolutions; selecting any number of continuous layers from the plurality of layers to form a subspace to grid the subspace step by step, including: recursively determining the value range of the implicit expression of each sub-grid of the current level to grid the sub-grids whose value range contains a threshold range to the next level, until each sub-grid of the current level is a single-layer grid that meets the corresponding layer resolution; selecting a sub-grid whose value range of the implicit expression contains the threshold range in the single-layer grid that meets the corresponding layer resolution as a key grid and filling it with the output value of the implicit expression of at least one representative point, so as to determine the slicing contour of each selected layer.

[0006] The second aspect of the present application discloses a slicing system, which includes: a layer creation module, which is used to create multiple continuous layers that can completely wrap an implicit expression model; wherein the multiple layers are respectively configured with layer resolutions; a subspace determination module, which is used to select any number of continuous layers from the multiple layers to form a subspace; a subspace slicing module, which includes: a gridding and filling unit, which is used to grid the subspace step by step, including: recursively executing to determine the value interval of the implicit expression of each sub-grid of the current level respectively to perform next-level gridding on the sub-grid whose value interval contains a threshold interval, until each sub-grid of the current level is a single-layer grid that meets the corresponding layer resolution; and selecting a sub-grid whose value interval of the implicit expression contains the threshold interval in the single-layer grid that meets the corresponding layer resolution as a key grid and filling it with the output value of the implicit expression of at least one representative point; a slicing contour determination unit, which is used to determine the slicing contour of each layer based on the key grid after each layer in the subspace is filled.

[0007] The third aspect of the present application discloses a computer device, comprising: a storage device for storing at least one program; a processing device connected to the storage device, for calling the at least one program from the storage device and implementing the slicing method described in the first aspect of the present application when executing it.

[0008] The fourth aspect of the present application discloses a computer-readable storage medium storing at least one program, which, when called and executed by a processor of a computer, implements the slicing method as described in the first aspect of the present application.

[0009] In a fifth aspect, the present application discloses a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the slicing method as described in the first aspect of the present application.

[0010] In summary, the present application discloses a slicing method and system, a computer device, a computer-readable storage medium, and a computer program product. The present application selects any number of continuous layers from a plurality of continuous layers that can completely enclose an implicit expression model to form a subspace for step-by-step meshing until each sub-mesh at the current level is a single-layer mesh that satisfies the corresponding layer resolution, and selects a sub-mesh in which the value range of the implicit expression includes the threshold range as a key mesh in the single-layer mesh that satisfies the corresponding layer resolution, and fills in the output value of the implicit expression of at least one representative point therein to determine the slicing contour of each selected layer. In this way, the present application does not need to first convert the implicit expression model into a triangular mesh model for slicing, and in the slicing process only fills in the output value of the implicit expression in the key mesh to determine the slicing contour, thereby reducing the amount of calculation in the slicing process and achieving efficient slicing of the implicit expression model. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The features and advantages of the inventions of the present application can be better understood by referring to the exemplary embodiments and drawings described in detail below. The drawings are briefly described as follows:

[0012] Figure 1 Shown is a schematic flow chart of a slicing method in one embodiment of the present application.

[0013] Figure 2 Shown is a schematic diagram of a parameter configuration window in an embodiment of the present application.

[0014] Figure 3 Shown is a schematic diagram of the layer positions of multiple layers in one embodiment of the present application.

[0015] Figure 4 Shown is a schematic diagram of multiple consecutive layers created in one embodiment of the present application.

[0016] Figure 5 Shown is a schematic diagram of a subspace selected in an embodiment of the present application.

[0017] Figure 6 Shown is a schematic diagram of a subspace selected in another embodiment of the present application.

[0018] Figure 7 Displayed for this application Figure 5 A schematic diagram of the subspace after the first meshing in the illustrated embodiment.

[0019] Figure 8 Displayed for this application Figure 6 A schematic diagram of the subspace after the first meshing in the illustrated embodiment.

[0020] Fig. 9 Displayed for this application Figure 7 The schematic diagram of the next-level gridding of the sub-grid whose value interval of the implicit expression in the illustrated embodiment includes the threshold interval.

[0021] Fig.10 It is a schematic diagram showing that a plurality of continuous layers constitute two subspaces in one embodiment of the present application.

[0022] Fig.11 Shown is a module block diagram of a slicing system in one embodiment of the present application.

[0023] Fig.12 Shown is a schematic diagram of the structure of a computer device in one embodiment of the present application. DETAILED DESCRIPTION

[0024] The following is a description of the embodiments of the present application by specific specific embodiments, and those familiar with the technology can easily understand the advantages of the present application and the technical effects that can be achieved by the content disclosed in this specification. In the following description, some embodiments can refer to the drawings pointed to. It should be understood that other embodiments without drawings can also be used, and specific steps, modules or units, electrical and operational changes can be made without departing from the spirit and scope of the present application. The detailed description below should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims published by the present application. The terms used herein are only for describing specific embodiments and are not intended to limit the present application.

[0025] Although the term first, second or third etc. is used to describe various elements or parameters in this article in some instances, these elements or parameters should not be limited by these terms. These terms are only used to distinguish an object or parameter from another object or parameter, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first threshold value can be referred to as the second threshold value, and similarly, the second threshold value can be referred to as the first threshold value, without departing from the scope of the various described embodiments, the first threshold value and the second threshold value are both describing a threshold value, but unless the context is otherwise clearly indicated, they are not the same threshold value.

[0026] Furthermore, as used in this article, the singular forms "one", "an" and "the" are intended to also include plural forms, unless there is an indication to the contrary in the context. It should be further understood that the terms "comprising", "including" indicate the presence of the described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. For example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment. In addition, the term "and / or" that may be used hereinafter, describes the association relationship of associated objects, indicating that three kinds of relationships may exist, for example, A and / or B, which can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / ", if not otherwise specified, generally represents that the associated objects before and after are a kind of "and / or" relationship. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two.

[0027] Some nouns or terms used in each embodiment of the present application are explained below, and the nouns or terms are also used as a part of the content of the invention. It will be appreciated by those skilled in the art that, unless otherwise defined, all terms including technical terms and scientific terms used herein have the same meaning as the general understanding of the technicians in the field to which the present application belongs. It should also be understood that those terms such as those defined in general dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and unless specifically defined as herein, will not be interpreted with an idealized or overly formal meaning.

[0028] The 3D printing device described in the embodiment of the present application prints a 3D object by curing the printing material layer by layer and accumulating each cured layer. Taking the 3D printing device as a 3D printing device including an energy radiation device as an example, the method of curing and accumulating the cured layers layer by layer is explained. Under the control of the control device, the energy radiation device prints layer by layer according to the slice contour of each layer (for example, exposes or scans layer by layer). When a layer is cured, the workbench moves a layer spacing (also called layer thickness) in the Z-axis direction, and a new layer of printing material is covered on the surface that has just been cured for printing. The newly cured layer is firmly bonded to the previous layer, and this is repeated, layer by layer, and finally the entire 3D object is formed. Among them, before the 3D printing device executes printing, it is necessary to generate slice data corresponding to the 3D object to be printed in the 3D printing pre-processing, and the slice data includes the slice contours of each slice layer (referred to as layer) of the 3D model corresponding to the 3D object to be printed and the layer spacing corresponding to each layer. When the layer is thin enough, it can be determined that the slice contours of the upper surface and the lower surface of the layer are consistent. In other words, when the layer is thin enough, the slice contour of the layer can be determined as a two-dimensional contour in the length and width directions. The slice contour of the layer can be described by an image or coordinate data.

[0029] The computer three-dimensional space described in the embodiments of the present application is a computer space with three dimensions (X-axis, Y-axis, and Z-axis) for constructing a 3D model. In the following embodiments, the direction corresponding to the X-axis in the layer and the grid is called the length direction, the direction corresponding to the Y-axis in the layer and the grid is called the width direction, and the direction corresponding to the Z-axis in the layer and the grid is called the height direction. In one embodiment, the 3D model is a model constructed in the field of 3D printing technology, and the 3D model constructed in the computer three-dimensional space can use a 3D printer to print out a 3D object in the actual physical space. Among them, the 3D object can be any 3D object such as aerospace parts, automotive parts, industrial equipment parts, handicrafts, medical equipment, etc.

[0030] The implicit expression model (also referred to as an implicit model or a model based on implicit expression) described in the embodiments of the present application expresses the geometric shape of the 3D model implicitly. The input of the implicit expression is the three-dimensional coordinates of a point in the three-dimensional space of the computer, and the output is a numerical value indicating the relative position relationship between the point and the surface of the 3D model, which is also referred to as an output value in some embodiments. Specifically, the three-dimensional coordinates of each point in the three-dimensional space of the computer are respectively input into the implicit expression, wherein the set of points with an output value of 0 defines the outer contour shape of the 3D model, and these points can be regarded as being on the 3D model. If the implicit output value corresponding to the point is less than 0, it indicates that the point is inside the 3D model, and if the implicit output value corresponding to the point is greater than 0, it indicates that the point is outside the 3D model. Of course, in other embodiments, depending on the difference of the implicit expression, if the implicit output value corresponding to the point is less than 0, it can also indicate that the point is outside the 3D model, and if the implicit output value corresponding to the point is greater than 0, it indicates that the point is inside the 3D model.

[0031] The implicit expression (or simply referred to as implicit) described in the embodiments of the present application can be of any type or any combination of types. For example, in one example, the implicit expression is configured as an equation, that is, the geometric shape of the 3D model is expressed by an equation. In this example, a 3D model of a sphere with a radius of 1 is taken as an example, and its corresponding implicit expression is an implicit equation: ,in, The value of is the output value of the implicit equation, is the input of the implicit equation. In another example, the implicit expression is configured to express the geometric shape of the 3D model through a function or a combination of functions, for example, a maximum value function max(), a minimum value function min(), a length function length(), and a combination thereof. In yet another example, the implicit expression is configured to express the geometric shape of the 3D model through a conversion relationship or a specified algorithm, for example, a triangular mesh is converted into an implicit conversion relationship. The above examples are only illustrative. In other examples, the implicit expression can also be configured as a combination of any of the above examples. The present application does not limit the type or method of implicit expression, as long as it can express the geometric shape of the 3D model in the manner defined above.

[0032] In view of the technical problem of how to efficiently slice the implicit model described in the background technology, the present application discloses a slicing method and system, a computer device, a computer-readable storage medium and a computer program product. The present application selects any number of continuous layers from a plurality of continuous layers that can completely wrap the implicit expression model to form a subspace for step-by-step meshing until each sub-mesh at the current level is a single-layer mesh that meets the corresponding layer resolution, and selects a sub-mesh in which the value range of the implicit expression includes the threshold range from the single-layer mesh that meets the corresponding layer resolution as a key mesh and fills in the output value of the implicit expression of at least one representative point therein to determine the slicing contour of each selected layer. In this way, the present application does not need to first convert the implicit expression model into a triangular mesh model for slicing, and in the slicing process only fills in the output value of the implicit expression in the key mesh to determine the slicing contour, thereby reducing the amount of calculation in the slicing process and achieving efficient slicing of the implicit expression model.

[0033] The present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. The technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments and technical effects obtained by ordinary technicians in this field without creative work should belong to the scope of protection of this application. The "one implementation method", "implementation method" or similar words mentioned in the whole text of this specification mean that the specific features, structures or characteristics described together with the implementation method are included in at least one implementation method of the present application. Therefore, in the whole text of this specification, the appearance of the phrases "in one implementation method", "in an implementation method" and similar words may (but not necessarily) refer to the same implementation method.

[0034] In some embodiments, the present application provides a slicing method, which can be executed by a computer device configured with a slicing system. The slicing system is a software tool or software module that can process data, and it executes the slicing method with the help of an operating environment provided by the hardware device and / or operating system in the computer device.

[0035] In one embodiment, the computer device can be configured as an electronic device, that is, the slicing method is executed by the electronic device. For example, the electronic device includes desktop computers, laptops, tablet computers, smart TVs, smart phones, tablets, industrial computers and other devices. The electronic device can also be an electronic device composed of a host with multiple virtual machines and a human-computer interaction device corresponding to each virtual machine (such as a touch screen, keyboard and mouse).

[0036] In one embodiment, the computer device may be configured as a server, that is, the slicing method is executed by the server. The server may be arranged on one or more physical servers according to various factors such as function and load. In some examples, the server may be a server based on a cloud architecture, and the server refers to a cloud computing platform provided by a cloud computing provider, and the cloud computing platform can provide services such as IaaS (Infrastructure-as-a-Service), PaaS (Platform-as-a-Service), and SaaS (Software-as-a-Service). Among them, the cloud computing platform includes a public cloud, a private cloud, and a hybrid cloud. In some examples, the server may be composed of a distributed or centralized server cluster. For example, the server cluster is composed of at least one physical server. Multiple virtual servers are configured in each physical server, each virtual server runs at least one functional module in the system, and each virtual server communicates through a network.

[0037] See also Figure 1 , which is a flow chart of a slicing method in an embodiment of the present application, as shown in the figure, the slicing method includes step S110, step S120, and step S130. The following takes the slicing method executed by a computer device as an example to illustrate each embodiment.

[0038] In step S110, the computer device creates a plurality of continuous layers that can completely wrap the implicit expression model; wherein the plurality of layers are respectively configured with layer resolutions. It should be noted that the plurality of layers are respectively configured with layer resolutions, which can be understood as each layer having layer resolution, and the subsequent division operation of the subspace formed by any number of continuous layers cannot be performed without restriction on the plane where the layer is located (for example, the layer is located in the XY plane, that is, the division of the subspace on the XY plane cannot be performed without restriction), and does not indicate whether the plurality of layers in step S110 have been divided according to the layer resolution. In addition, the plurality of continuous layers created in the relevant embodiments of this step can be understood as pre-defined plurality of continuous layers, and it is not necessarily necessary to present them in a visual manner in the display interface of the computer device.

[0039] The continuous multiple layers that can completely enclose the implicit expression model refer to the overall space of the continuous multiple layers that can completely enclose the implicit expression model. The dimensions of the overall space of the continuous multiple layers in the length direction, width direction, and height direction are not less than the dimensions of the bounding box of the implicit expression model in the length direction, width direction, and height direction. The bounding box will be described in detail later.

[0040] Among them, the layer resolution is used to indicate the granularity at which the layer can be gridded, which can be predefined or pre-stored, or determined based on user input. In one embodiment, the layer resolution is configured as the size of the smallest unit into which the layer can be divided (or can be understood as the unit size). Taking the layer alignment of the XY plane in the three-dimensional space of the computer as an example, the layer resolution is the size of the smallest unit into which the layer is divided in the X-axis and Y-axis directions. In the example of the layer alignment of the XY plane, the height direction of the layer corresponds to the Z-axis direction. In some subsequent embodiments, the grid division will be explained by taking the layer alignment of the XY plane and the height direction corresponding to the Z-axis direction as an example, which should not be understood as a limitation to the present application. Those skilled in the art may also align the layers in other ways under the inventive concept of the present application, and only need to make corresponding directional adjustments to the division method.

[0041] Furthermore, the layer resolution includes the resolution in the X-axis direction of the layer (which may also be referred to as the resolution in the length direction of the layer or the X-axis resolution of the layer), and the resolution in the Y-axis direction of the layer (which may also be referred to as the resolution in the width direction of the layer or the Y-axis resolution of the layer). Taking the layer resolution as the size of the minimum unit of the above-mentioned layer as an example, the resolution in the X-axis direction of the layer refers to the size of the minimum unit of the layer in the X-axis direction, which can be understood as the length of the minimum unit of the layer, and the resolution in the Y-axis direction of the layer refers to the size of the minimum unit of the layer in the Y-axis direction, which can be understood as the width of the minimum unit of the layer. Among them, the layer resolutions of different layers may be the same or different, and the resolutions in the X-axis and Y-axis directions on the same layer may be the same or different. For the sake of convenience of explanation, in the following embodiments, the layer resolutions of different layers are the same and the resolutions in the X-axis and Y-axis directions on the same layer are also the same.

[0042] In one embodiment, the step of creating multiple continuous layers that can completely wrap the implicit expression model includes creating the multiple layers based on the length, width and height information of the bounding box of the implicit expression model, the grid parameters of the layer plane, and the layer spacing of the multiple layers.

[0043] The bounding box of the implicit expression model can be defined as the minimum space that encloses the implicit expression model, which can be, for example, a bounding box in the form of AABB (Axis Aligned Bounding Box) or a bounding box in the form of OBB (Oriented Bounding Box). The length, width, and height information of the bounding box include the length information of the bounding box, the width information of the bounding box, and the height information of the bounding box, wherein the length information of the bounding box is the size occupied by the bounding box on the X-axis (i.e., the length of the bounding box), and correspondingly, the width information of the bounding box is the size occupied by the bounding box on the Y-axis (i.e., the width of the bounding box), and the height information of the bounding box includes the Z-axis coordinates of the lowest and highest points of the bounding box, and the height information of the bounding box can also include the size occupied by the bounding box on the Z-axis (i.e., the height of the bounding box).

[0044] Among them, the grid parameters of the layer plane (also referred to as the grid parameters of the layer) may be, for example, predefined or pre-stored, or may also be determined based on user input. In some examples, the grid parameters of the layer plane include the minimum unit size of the grid of each layer, and the minimum unit size may further include the size (length) occupied by the minimum unit on the X-axis and the size (width) occupied on the Y-axis. In another example, the grid parameters of the layer plane (also referred to as the grid parameters of the layer) include the minimum number of units in the length and width directions of each layer. It should be noted that the grid parameters of the layer planes of different layers may be the same or different. For ease of explanation, in the following embodiments, the grid parameters of the layer planes of different layers are the same as an example for explanation.

[0045] The interlayer spacing is the size of the layer in the height direction (ie, the Z-axis direction). The interlayer spacings of different layers may be the same or different.

[0046] In one embodiment, creating a plurality of continuous layers that can completely wrap the implicit expression model further includes the step of providing a parameter configuration window for the user to input the grid parameters of the layer spacing and / or the layer plane. The parameter configuration window can only allow the user to input the grid parameters of the layer spacing or the layer plane, or can also allow the user to input the grid parameters of the layer spacing and the layer plane at the same time. For example, a parameter configuration window allows the user to input the grid parameters of the layer spacing and the layer plane at the same time. Figure 2, which is a schematic diagram of the parameter configuration window in one embodiment of the present application, is shown by taking the grid parameters of the layer plane including the minimum unit size of the grid of each layer, and the minimum unit size of the grid of each layer is the same, and the interlayer spacing of each layer is the same as an example. The parameter configuration window provides input boxes for interlayer spacing, the size of the minimum unit of the grid in the X-axis direction, and the size of the minimum unit of the grid in the Y-axis direction. The user can enter data in the corresponding input boxes to complete the input of interlayer spacing and the grid parameters of the layer plane. It should be understood that Figure 2 This is just an example. For example, in an example where the interlayer spacing of each layer is different or the minimum unit size of the grid of each layer is different, the parameter configuration window may provide an input window for configuring different interlayer spacing or the minimum unit size of the grid of each layer. In addition, in an example where the grid parameter configuration of the layer plane is other parameters, those skilled in the art may also make adaptive adjustments to the content and interface layout that can be displayed in the parameter configuration window under the guidance of this application, and this application does not limit this.

[0047] In one embodiment, the step of creating the multiple layers based on the length, width and height information of the bounding box of the implicit expression model, the grid parameters of the layer plane, and the layer spacing of the multiple layers includes: determining the layer positions of the multiple layers based on the height information of the bounding box of the implicit expression model and the layer spacing of the multiple layers, and determining the length and width dimensions of the multiple layers based on the length and width information of the bounding box and the grid parameters of the layer plane, so as to create the continuous multiple layers.

[0048] The layer positions of the multiple layers are used to indicate the height positions of the multiple layers. For example, the layer positions of the multiple layers can be represented by the Z-axis coordinates of the upper surfaces of the multiple layers and / or the Z-axis coordinates of the lower surfaces of the multiple layers.

[0049] In one embodiment, the computer device determines the layer positions of the multiple layers based on the height information and layer spacing of the bounding box of the implicit expression model. In this embodiment, the height information of the bounding box includes the Z-axis coordinates of the lowest point and the highest point of the bounding box. Specifically, the layer spacing of the corresponding layers is superimposed layer by layer based on the Z-axis coordinate of the lowest point of the bounding box, and the superposition is stopped after the superimposed layer spacing is greater than the Z-axis coordinate of the highest point of the bounding box, so as to obtain the layer positions of the multiple layers. For example, refer to Figure 3, which is a schematic diagram showing the layer positions of multiple layers in one embodiment of the present application. As shown in the figure, the Z-axis coordinate of the lowest point and the Z-axis coordinate of the highest point of the bounding box B are Min_z and Max_z respectively. The Z-axis coordinate Min_z of the lowest point of the bounding box B is used as the Z-axis coordinate of the lower surface of the first layer, and the layer spacing d1 of the first layer c1 is added as the upper surface coordinate Min_z+d1 of the first layer c1, that is, the lower surface coordinate of the second layer c2. After increasing the layer position Min_z+d1 of the first layer c1 by the layer spacing d2 of the second layer c2, the upper surface coordinate Min_z+d1+ d2 of the second layer c2 can be determined, that is, the lower surface coordinate of the third layer c3. This continues for subsequent layers until the following step is completed. Figure 3 As shown in FIG. 1 , the upper surface coordinates Min_z+d1+ d2+…+dn-1 of the determined n-1th layer cn-1 are less than or equal to the highest point Max_z of the bounding box, while the upper surface coordinates Min_z+d1+d2+…+dn-1+dn of the nth layer cn are greater than the highest point of the bounding box, then the calculation of determining the layer positions of multiple layers is stopped, as shown in FIG. Figure 3 As shown, the layer positions of n layers are finally determined, and these n layers can completely wrap the implicit expression model in the height direction. It should be understood that Figure 3 Only the determination of the layer position of each layer is illustrated, and the plane size of the layer is not included (it can also be understood that the format size or length and width of the layer are not illustrated). In addition, the calculation method for determining the layer positions of the multiple layers in the above embodiment is limited to examples. Those skilled in the art can adaptively change the determination method under the guidance of this application to obtain the layer positions of multiple layers. This application does not impose any restrictions on this, as long as the total height of the multiple layers is not less than the height of the bounding box of the implicit expression model.

[0050] In one embodiment, for example, the grid parameters of the layer plane include the minimum unit size of the grid of each layer, and the computer device further determines the length and width of the multiple layers based on the length and width information of the bounding box and the grid parameters of the layer plane. Specifically, the computer device can determine the size of each layer in the length direction according to the length of the minimum unit of the grid of each layer and the length of the bounding box, and can determine the size of each layer in the width direction according to the width of the minimum unit of the grid of each layer and the width of the bounding box. It should be understood that in the embodiment where the grid parameters of the layer plane of each layer are the same, the length and width of the multiple layers are the same, and the overall space of the multiple layers is a regular three-dimensional space (such as a cube space or a rectangular space). In other embodiments where the grid parameters of the layer plane of each layer are different, the length and width of the multiple layers are also different, and the overall space of the multiple layers can be an irregular three-dimensional space.

[0051] Taking the example that the grid parameters of the layer plane of each layer are the same, how the computer device determines the length and width of multiple layers is explained. Specifically, the computer device can round up the value of the bounding box length divided by the minimum unit length as the number of minimum units in the length direction, and multiply this number by the minimum unit length as the length of multiple layers. The width of multiple layers can be determined in the same way. Of course, other methods can also be used to determine it. For example, the value of the bounding box length divided by the minimum unit length is rounded up and then added to the value after a preset number is used as the number of minimum units in the length direction. The number is multiplied by the minimum unit length as the length of multiple layers. The preset number is, for example, any integer from 1 to 10, and the corresponding width of multiple layers can be determined in the same way. The present application does not limit the method of determining the length and width of multiple layers. It is only necessary to ensure that the length and width of multiple layers are not less than the length and width of the bounding box. This ensures that the created multiple continuous layers can completely surround the implicit expression model in the length and width directions.

[0052] It should be noted that in embodiments where the grid parameters of each layer plane are different, a calculation to determine the length and width can be performed once for each different layer plane grid parameter according to the description of the above embodiments to determine the length and width dimensions of multiple layers.

[0053] In another embodiment, for example, the grid parameters of the layer plane include the minimum number of units of each layer in the length and width directions, and the computer device can directly determine the length and width of multiple layers according to the length and width of the bounding box of the implicit expression model, wherein the method of determining the length and width of multiple layers can be, for example, to increase a certain size on the basis of the length and width of the bounding box to determine the length and width of multiple layers, or directly determine the length and width of the bounding box as the length and width of multiple layers.

[0054] According to the description of any of the above embodiments, the computer device may determine the layer positions of the multiple layers and the length and width of the multiple layers, and then the computer device may create the multiple continuous layers according to the determined layer positions of the multiple layers and the length and width of each layer. Figure 4 , which is a schematic diagram of multiple continuous layers created in one embodiment of the present application. As shown in the figure, the number of the multiple continuous layers is 7, that is, the multiple continuous layers include a first layer c1, a second layer c2, a third layer c3, a fourth layer c4, a fifth layer c5, a sixth layer c6, and a seventh layer c7, and the length and width of each layer are the same.

[0055] In one embodiment, the slicing method further includes a step of determining the layer resolution based on the grid parameters of the layer plane. In one example, the grid parameters of the layer plane include the minimum unit size of the grid of each layer, and the minimum unit size of the grid of each layer can be directly used as the layer resolution of each layer. In another example, the grid parameters of the layer plane include the minimum number of units of each layer in the length and width directions, and the computer device determines the layer resolution of each layer based on the minimum number of units of each layer in the length direction and the width direction and the length and width of each layer. Specifically, the X-axis resolution of each layer is configured as the ratio of the length of each layer to the minimum number of units of each layer in the length direction, and the Y-axis resolution of each layer is configured as the ratio of the width of each layer to the minimum number of units of each layer in the width direction.

[0056] In step S120, the computer device selects any number of continuous layers from the multiple layers to form a subspace to grid the subspace step by step, including: recursively determining the value interval of the implicit expression of each sub-grid of the current level to grid the sub-grids whose value interval contains a threshold interval to the next level, until each sub-grid of the current level is a single-layer grid that meets the corresponding layer resolution; wherein, the any number of continuous layers includes a single layer or multiple layers (for example, two or more continuous layers), and the implicit expression is the implicit expression of the implicit expression model, which will not be repeated in subsequent embodiments.

[0057] In one embodiment, the computer device selects any number of continuous layers from the multiple layers to form a subspace. In an embodiment where the any number of continuous layers is multiple layers, the computer device may select multiple continuous layers from the multiple layers to form the subspace. Specifically, the entire space corresponding to the selected multiple continuous layers is used as the subspace. For example, see Figure 5 , which is a schematic diagram of a subspace selected in an embodiment of the present application. As shown in the figure, the computer device selects the continuous first layer c1, second layer c2, third layer c3, fourth layer c4, fifth layer c5, sixth layer c6, and seventh layer c7 from the multiple layers (first layer c1, second layer c2, third layer c3, fourth layer c4, fifth layer c5, sixth layer c6, and seventh layer c7) to form a subspace V1. In the embodiment where any of the continuous layers is a single layer, the computer device can select one layer from the multiple layers to form a subspace, for example, see Figure 6 , which is a schematic diagram of a subspace selected in another embodiment of the present application. As shown in the figure, the computer device selects the first layer c1 from the multiple layers (the first layer c1, the second layer c2, the third layer c3, the fourth layer c4, the fifth layer c5, the sixth layer c6, and the seventh layer c7) to form a subspace V2.

[0058] In one embodiment, when selecting multiple layers to constitute the subspace layer, in order to enable the subspace to be divided in the length and width directions when performing step-by-step gridding, continuous layers with the same layer resolution need to be divided into one subspace, that is, the layer resolution of each layer in the subspace is the same.

[0059] In one embodiment, the computer device also provides a layer number configuration window for the user to configure the number of layers constituting the subspace. Specifically, the user can enter the number of layers constituting the subspace in the configuration window, and then the computer device can select a number of continuous layers corresponding to the number of layers input from the multiple layers based on the number of layers input by the user to constitute a subspace. For example, if the number of layers constituting the subspace input by the user is 1, the computer device selects a layer from the multiple layers to constitute a subspace. It should be noted that when the number of layers constituting the subspace input by the user is more than 2, the computer device can constitute a subspace with continuous layers not exceeding the number of layers input. In this way, the user can enter different numbers of layers according to the memory of the computer device. For example, when the computer memory is low, 1 layer or a smaller number of layers can be entered to avoid the problem of slicing failure due to memory limitations.

[0060] In one embodiment, the step of meshing the subspaces step by step by the computer device further includes meshing the subspaces for the first time to obtain a plurality of initially meshed subgrids.

[0061] In the embodiment where the subspace includes multiple layers, the computer device evenly divides the subspace in the length direction, width direction, and height direction to obtain multiple subgrids after the first gridding. Figure 7 , showing that this application is Figure 5 The schematic diagram of the subspace after the first meshing in the embodiment shown in the figure is as shown in the figure. Figure 5 The length, width, and height directions of the subspace V1 are divided into two equal parts to obtain eight subgrids (subgrid v11, subgrid v12, subgrid v13, subgrid v14, subgrid v15, subgrid v16, subgrid v17, and subgrid v18). In the embodiment where the subspace includes a single layer, the computer device divides the subspace equally in the length and width directions to obtain multiple subgrids after the first gridding. In this embodiment, the subspace can be regarded as a two-dimensional plane in the length and width directions for two-dimensional division. Please refer to Figure 8 , showing that this application is Figure 6 The schematic diagram of the subspace after the first meshing in the embodiment shown in the figure is as shown in the figure. Figure 6 The subspace V2 is divided into two equal parts in the length and width directions to obtain four subgrids (subgrid v21, subgrid v22, subgrid v23, and subgrid v24).

[0062] For convenience, Figure 7 and Figure 8 The divided subgrids are illustrated in a separate listing manner, which does not mean that the subgrids will be separated or arranged in the manner shown in the figure.

[0063] It should be noted that although Figure 7 and 8 In the embodiment shown, the way of equal division in the length direction, width direction, and height direction is bisection, but in other embodiments, it can also be divided into three equal parts, four equal parts, or other equal parts in different numbers in different directions, or it can be approximate equal division, and the approximate equal division means that the difference of the subgrids in the corresponding directions after the approximate equal division is not large (for example, the difference of the number of minimum units contained in the subgrids in the corresponding directions after the approximate equal division is within 50%). For example, when the number of minimum units contained in the subspace in the length, width, and / or height direction is odd, the corresponding direction can be approximately equal divided. For example, when the subspace is composed of an odd number of layers, the computer device can perform an approximate equal division in the height direction of the subspace V1. Taking the subspace composed of 7 layers and approximately divided into approximately two equal parts as an example, after the approximate bisection, the size of the 8 subgrids in the height direction can include the height corresponding to 3 layers and the height corresponding to 4 layers. In the following embodiments, for the convenience of explanation, the way of equal division in different directions is to divide into two equal parts as an example.

[0064] The computer device may use the first gridding as the first level gridding, and recursively execute the multiple subgrids after the first level gridding as the multiple subgrids of the first level to respectively determine the value interval of the implicit expression of each subgrid of the current level to perform the next level gridding on the subgrids whose value interval contains a threshold interval, until each subgrid of the current level is a single-layer grid that meets the layer resolution of the corresponding layer. Recursive execution is to select subgrids with the same selection conditions to continue the next level of subdivision until the termination condition is reached. In this embodiment, the selection condition of each level is that the value interval of the implicit expression of the subgrid of the level contains the threshold interval, and the termination condition is that each subgrid of the level is a single-layer grid that meets the corresponding layer resolution, that is, the termination condition is that each subgrid of the level is a single-layer grid and meets the corresponding layer resolution. Among them, the single-layer grid means that the subgrid contains only one layer in the height direction, and the subgrid meets the corresponding layer resolution means that the subgrid meets the resolution of the layer constituting the subspace. Specifically, the subgrid meets the corresponding layer resolution and needs to reach the corresponding resolution in both the length and width directions.

[0065] Specifically, the recursive execution process described in this embodiment can be expanded as follows: when each sub-grid of the first level does not reach the corresponding layer resolution and is not a single-layer grid, the computer device will respectively determine the value interval of the implicit expression of each sub-grid of the first level, and perform second-level gridding on the sub-grids whose value interval includes the threshold interval, and obtain each sub-grid of the second level. Then, when each sub-grid of the second level does not reach the corresponding layer resolution and is not a single-layer grid, the computer device will continue to determine the value interval of the implicit expression of each sub-grid of the second level, and continue to perform third-level gridding on the sub-grids whose value interval includes the threshold interval, and obtain each sub-grid of the third level. In this way, the next level of gridding is continuously performed until each sub-grid of the current level is a single-layer grid that meets the corresponding layer resolution, and then gridding is no longer continued.

[0066] In one embodiment, the step of respectively determining the value interval of the implicit expression of each sub-grid of the current level to perform next-level gridding on the sub-grids whose value intervals include a threshold value interval includes respectively determining the value interval of the implicit expression of each sub-grid of the current level, comparing the threshold value interval with the value interval of each sub-grid, and gridding the corresponding sub-grid to the next level under the condition that the value interval is judged to include the threshold value interval.

[0067] The value interval of the implicit expression of the sub-grid represents the estimated range of the numerical interval of all output values ​​obtained by inputting the implicit expression of the implicit expression model into all points in the sub-grid. The estimated range is wider than (or greater than) the numerical interval formed by the minimum and maximum of all output values. For example, after all points in a sub-grid input the implicit expression, the numerical interval formed by the minimum and maximum of the output values ​​is [i, j]. Then, the lower limit i1 in the value interval [i1, j1] of the implicit expression of the sub-grid is less than or equal to the lower limit i of the numerical interval, and the upper limit j1 is greater than or equal to the upper limit j of the numerical interval.

[0068] In one embodiment, a computer device determines a value interval of a sub-mesh based on the diagonal vertices of the sub-mesh. The diagonal vertices of the sub-mesh are the two endpoints of the body diagonal of the sub-mesh. For example, the diagonal vertices of the sub-mesh are configured to correspond to the point closest to the origin of the coordinate system (the minimum position point) and the point farthest from the origin of the coordinate system (the maximum position point). In one example, for example, the implicit expression is configured as an equation, a function, a combination of functions, or a combination of function equations. The computer device may pre-store a corresponding interval range obtaining algorithm, and the computer device may call the interval range obtaining algorithm based on the determined diagonal vertices of the sub-mesh to output the value interval. In another example, the computer device determines the body diagonal length of the sub-mesh based on the diagonal vertices of the sub-mesh to determine the value interval of the sub-mesh based on the output value of the implicit expression of the body diagonal length and the center point of the sub-mesh. Specifically, the computer device determines the body diagonal length r of the sub-mesh based on the coordinates of any pair of diagonal vertices of the sub-mesh, and the output value p obtained by inputting the coordinates of the center point of the sub-mesh into the implicit expression, and uses the difference between the output value p and half of the body diagonal length r as the lower limit of the value range, and uses the sum of the output value p and half of the body diagonal length r as the upper limit of the value range, thereby obtaining the value range of the sub-mesh as [p-0.5r, p+0.5r]. In this embodiment, the value range of the sub-mesh can be quickly obtained while ensuring that the value range must contain the actual output value range, thereby improving the gridding calculation speed of the implicit expression model.

[0069] In another embodiment, the computer device determines the value interval of the sub-mesh based on the key points of the sub-mesh. Specifically, the key points of the sub-mesh are respectively substituted into the implicit expression to obtain multiple output values, and the interval consisting of the minimum and maximum values ​​of the multiple output values ​​obtained is determined as the value interval of the sub-mesh. In one example, the key points include the vertices of the sub-mesh, the center point of the sub-mesh, the midpoint of the edge of the sub-mesh, the center point of the face of the sub-mesh, or the corner vertex of the sub-mesh, but it is not limited to this. In other examples, those skilled in the art can add other points in the sub-mesh (such as points on the body diagonal) as key points according to the accuracy requirements under the enlightenment of this application.

[0070] It should be noted that the present application does not limit the method for determining the value range of the implicit expression of the sub-grid, as long as the estimated value of the output value range can be quickly obtained.

[0071] According to the method of determining the value interval of the sub-grid described in any of the above embodiments, the value interval of the implicit expression of each sub-grid of the current level can be determined, so as to compare the threshold interval with the value interval of each sub-grid respectively, and then determine whether the value interval of each sub-grid includes the threshold interval. In the following embodiments, the implicit configuration is that the implicit output value corresponding to the point is less than 0, indicating that the point is inside the 3D model, and the implicit output value corresponding to the point is greater than 0, indicating that the point is outside the 3D model.

[0072] In one embodiment, the threshold interval is configured as a boundary value of the implicit expression. The boundary value of the implicit expression represents the output value of the implicit expression of the point on the outer contour of the implicit expression model. Taking the output value of 0 to represent the point on the outer contour as an example, the boundary value is 0, that is, in this embodiment, the threshold interval is configured as a single point interval [0, 0]. In this embodiment, comparing the threshold interval with the value interval of each sub-grid can be, for example, comparing the lower limit value and / or upper limit value of the value interval of the sub-grid with the boundary value. Further, in one example, when the lower limit value of the value interval of the sub-grid is greater than the boundary value, it is determined that the value interval is greater than the threshold interval. At this time, the sub-grid is completely outside the implicit expression model. For example, the value interval of a sub-grid is [1, 2], and the boundary value is 0, then it is determined that the value interval of the sub-grid is greater than the threshold interval. In another example, when the upper limit value of the value interval of a sub-grid is less than the boundary value, it is determined that the value interval is less than the threshold interval. At this time, the sub-grid is completely located inside the implicit expression model. For example, the value interval of a sub-grid is [-2, -1], and the boundary value is 0, then the value interval of the sub-grid is determined to be less than the threshold interval. In yet another example, when the lower limit value of the value interval of a sub-grid is less than or equal to the boundary value and the upper limit value of the value interval is greater than or equal to the boundary value, it is determined that the value interval of the corresponding sub-grid includes the threshold interval. At this time, the sub-grid may be completely located inside the implicit expression model, may be completely located outside the implicit expression model, or may be partially located inside the implicit expression model and partially located outside the implicit expression model. For example, the value interval of a sub-grid is [-1, 1], and the boundary value is 0, then the value interval of the sub-grid is determined to include the threshold interval.

[0073] In another embodiment, the threshold interval is configured as an interval with a first threshold as an upper limit and a second threshold as a lower limit, which includes the boundary value of the implicit expression. In other words, the boundary value of the implicit expression is included in the threshold interval with the first threshold as an upper limit and the second threshold as a lower limit. In one example, the first threshold is a positive number close to 0, and the second threshold is a negative number close to 0. For example, the first threshold can be any positive number between [0-0.5], and the second threshold can be any negative number between [-0.5-0]. In this embodiment, comparing the threshold interval with the value interval of each sub-grid can be, for example, comparing the lower limit value of the value interval of the sub-grid with the upper limit value of the threshold interval and / or comparing the upper limit value of the value interval of the sub-grid with the lower limit value of the threshold interval. Furthermore, in one example, when the lower limit value of the value interval of a sub-grid is greater than the first threshold value, it is determined that the value interval is greater than the threshold interval. At this time, the sub-grid is completely outside the implicit expression model. For example, the threshold interval is configured as [-0.1, 0.1], and the value interval of a sub-grid is [0.2, 0.4], then it is determined that the value interval is greater than the threshold interval. In another example, when the upper limit value of the value interval of a sub-grid is less than the second threshold value, it is determined that the value interval is less than the threshold interval. At this time, the sub-grid is completely inside the implicit expression model. For example, the threshold interval is configured as [-0.1, 0.1], and the value interval of a sub-grid is [-1, -0.3], then it is determined that the value interval is less than the threshold interval. In another example, when the lower limit of the value interval of the sub-grid is less than or equal to the first threshold value and the upper limit of the value interval is greater than or equal to the second threshold value, it is determined that the value interval of the corresponding sub-grid includes the threshold interval. At this time, the sub-grid may be completely inside the implicit expression model, or completely outside the model, or partly inside the model and partly outside the model. For example, if the value interval of a sub-grid is [-1, 0.05] and the threshold interval is [-0.1, 0.1], it is determined that the value interval of the sub-grid includes the threshold interval.

[0074] In other embodiments, when the implicit is configured so that the implicit output value corresponding to the point is less than 0, indicating that the point is outside the 3D model, and the implicit output value corresponding to the point is greater than 0, indicating that the point is inside the 3D model, then under the condition that the value interval is greater than the threshold interval, it is determined that the sub-grid is completely located inside the implicit expression model; under the condition that the value interval is less than the threshold interval, it is determined that the sub-grid is completely located outside the implicit expression model.

[0075] The computer device performs next-level gridding on the corresponding sub-grid under the condition that the value interval contains the threshold interval. In one embodiment, the next-level gridding is configured to traverse the length, width, and height directions of the current-level sub-grid to perform gridding in a manner of averaging the directions in which averaging can be performed. Specifically, when the current-level sub-grid is gridded to the next level, the length, width, and height directions of the current-level sub-grid are traversed, and the directions in the length and width directions that do not reach the layer resolution are regarded as directions in which averaging can be performed, and when the height direction is not a single-layer grid, the height direction is regarded as a direction in which averaging can be performed, and the directions in which averaging can be performed on the sub-grid of the current level are averaged to achieve the next-level gridding of the sub-grid. Among them, the method of averaging the directions in which averaging can be performed on the sub-grid of the current level is the same or similar to the method of averaging the length direction, width direction, and height direction in the first gridding mentioned above, and will not be repeated here.

[0076] Taking the method of performing equal division in the direction where equal division can be performed as bisection as an example for detailed description, if the length, width and height directions are all directions where equal division can be performed, then after performing the next level of gridding on a sub-grid, the sub-grid can be divided into 8 sub-grids. In this embodiment, the method of dividing the sub-grids is the same as Figure 7 The division method of the first gridding is the same as shown in FIG. 1 ; if only two of the length, width and height directions are directions in which equal division can be performed, then after performing the next level of gridding on a subgrid, the subgrid can be divided into four subgrids. In this embodiment, the subgrid division method is the same as Figure 8 The division method of the first meshing is the same as shown; if only one of the length, width and height directions is a direction in which equal division can be performed, then a sub-grid can be divided into two sub-grids after the next level of meshing is performed on the sub-grid.

[0077] In one specific embodiment, see Fig. 9 Combined with Figure 7 , Fig. 9 Displayed for this application Figure 7 The schematic diagram of the next level of gridding of the subgrids whose value interval of the implicit expression in the embodiment shown includes the threshold interval, for example, according to any of the above-mentioned embodiments, Figure 7In the multiple subgrids (subgrid v11, subgrid v12, subgrid v13, subgrid v14, subgrid v15, subgrid v16, subgrid v17, subgrid v18) after the first level of gridding, the subgrids whose implicitly expressed value intervals include the threshold interval include subgrid v11, subgrid v12, subgrid v15, and subgrid v16. Then, only subgrid v11, subgrid v12, subgrid v15, and subgrid v16 need to be subdivided at the next level, while the remaining subgrids (i.e., subgrid v13, subgrid v14, subgrid v15, subgrid v16, subgrid v17, and subgrid v18) need to be subdivided at the next level. 4. Subgrid v17 and subgrid v18 do not need to be further subdivided. Taking the next level of meshing of subgrid v16 as an example, the length, width and height directions of subgrid v16 will be traversed respectively. For example, if the length and width directions of subgrid v16 do not reach the corresponding resolution, the length and width directions of subgrid v16 will be used as the directions for performing average division. For example, if the height direction of subgrid v16 is not a single-layer grid, the height direction of subgrid v16 will also be used as the direction for performing average division. After averaging the three directions, the second level of meshing of subgrid v16 is realized, that is, Fig. 9 The subgrid v16 is divided into 8 subgrids. The next level of meshing for subgrid v11, subgrid v12, and subgrid v15 is similar to that for subgrid v16. The length, width, and height directions of subgrid v11, subgrid v12, and subgrid v15 are traversed respectively. For example, the length, width, and height directions of subgrid v11, subgrid v12, and subgrid v15 are all directions that can be averaged. After the three directions are averaged, the second level of meshing for subgrid v11, subgrid v12, and subgrid v15 is realized. Fig. 9 The sub-grid v11, sub-grid v12, and sub-grid v15 can also be divided into 8 sub-grids. Due to the viewing angle, not all the divided sub-grids are displayed.

[0078] In one embodiment, the step of respectively determining the value range of the implicit expression of each sub-grid of the current level to perform next-level gridding on the sub-grids whose value range includes a threshold range also includes step S1200.

[0079] In step S1200, the computer device fills the corresponding subgrid with a value representing a value outside the implicit expression model when the value interval is greater than the threshold interval, and fills the corresponding subgrid with a value representing a value within the implicit expression model when the value interval is less than the threshold interval. In this embodiment, the implicit configuration is that the implicit output value corresponding to the point is less than 0, indicating that the point is inside the 3D model, and the implicit output value corresponding to the point is greater than 0, indicating that the point is outside the 3D model.

[0080] In one embodiment, according to the comparison description of the value interval and the threshold interval in the aforementioned embodiment, when the value interval of a sub-grid is greater than the threshold interval, it means that the sub-grid is completely outside the implicit expression model, and the sub-grid can be filled with a numerical value represented outside the implicit expression model. When the value interval of a sub-grid is less than the threshold interval, it means that the sub-grid is completely within the implicit expression model, and the sub-grid can be filled with a numerical value represented within the implicit expression model. Among them, the numerical value represented outside the implicit expression model and the numerical value represented within the implicit expression model can be configured as any different numerical values. For example, the numerical value represented outside the implicit expression model is configured as 0, and the numerical value represented within the implicit expression model is configured as 2.

[0081] Please continue reading Fig. 9 Combined with Figure 7 , after comparing subgrid v13, subgrid v14, subgrid v17, and subgrid v18, the comparison results are all that the value interval is greater than the threshold interval, then subgrid v13, subgrid v14, subgrid v17, and subgrid v18 are all filled with values ​​outside the implicit expression model, for example, they are all filled with 0. It should be noted that, when the threshold interval is configured as the boundary value of the implicit expression, or the threshold interval is configured as an interval containing the boundary value of the implicit expression with the first threshold as the upper limit and the second threshold as the lower limit, the method of judging whether the value interval is greater than the threshold interval and the method of judging whether the value interval is less than the threshold interval are the same or similar to those described in the aforementioned embodiments, and are not repeated here.

[0082] In other embodiments, when the implicit is configured so that the implicit output value corresponding to the point is less than 0, indicating that the point is outside the 3D model, and the implicit output value corresponding to the point is greater than 0, indicating that the point is inside the 3D model, the corresponding sub-grid can be filled with a value representing a value within the implicit expression model under the condition that the value interval is greater than the threshold interval, and the corresponding sub-grid can be filled with a value representing a value outside the implicit expression model under the condition that the value interval is less than the threshold interval.

[0083] In one embodiment, when filling a subgrid with a numerical value outside the implicit expression model or a numerical value within the implicit expression model, the numerical value outside the implicit expression model or the numerical value within the implicit expression model can be filled in the position of the center point in the subgrid.

[0084] In one embodiment, in order to reduce the amount of data for subsequent calculations, subgrids whose value intervals are larger than the threshold interval and subgrids whose value intervals are smaller than the threshold interval may not be filled with values.

[0085] It should be noted that when comparing the threshold interval with the value interval of each sub-grid, the value interval of each sub-grid can be compared with the threshold interval respectively after the calculation is completed, or the value interval of each sub-grid can be compared with the threshold interval after the calculation of the value interval of each sub-grid is completed. A similar situation also includes the step of gridding the corresponding sub-grids to the next level. When executing this step, all sub-grids that meet the condition that the value interval includes the threshold interval can be gridded to the next level together, or each sub-grid can be gridded to the next level under the condition that the value interval of each sub-grid is determined to include the threshold interval. A similar situation also includes step S1200.

[0086] Further, according to step S120, when each sub-grid of the current level is a single-layer grid that satisfies the corresponding layer resolution, the next level of gridding will be stopped, otherwise the next level of gridding will be continued for the selected sub-grid according to the various embodiments of step S120 provided above. Fig. 9 If all sub-grids (i.e., 32 sub-grids) after sub-grid v11, sub-grid v12, sub-grid v15, and sub-grid v16 are divided, the length direction reaches the resolution in the length direction, the width direction reaches the resolution in the width direction, and the height direction is also a single-layer grid, then it means that the 32 sub-grids after the second-level gridding are all single-layer grids that meet the corresponding layer resolution, then the next-level gridding of sub-grid v11, sub-grid v12, sub-grid v15, and sub-grid v16 is stopped, otherwise the value intervals will continue to be determined for the 32 sub-grids respectively, and the next-level gridding will continue for the sub-grids that meet the value interval containing a threshold interval.

[0087] After the termination condition is reached in step S120, that is, until the divided sub-grid is a single-layer grid that meets the layer resolution of the corresponding layer, the meshing will be stopped and step S130 will be executed. In step S130, the computer device selects a sub-grid in which the value interval of the implicit expression includes the threshold interval in the single-layer grid that meets the corresponding layer resolution as a key grid and fills in the output value of the implicit expression of at least one representative point thereof to determine the slice contour of each selected layer. It should be understood that in step S130, the value interval of the implicit expression of the single-layer grid that meets the corresponding layer resolution will be determined according to the embodiment provided by step S120, so as to make a judgment to select the key grid. Of course, the process of determining the value interval of the implicit expression of the single-layer grid that meets the corresponding layer resolution can also be performed in step S120, that is, when the sub-grid meets the corresponding layer resolution and is a single-layer grid, step S120 will further determine the value interval of the implicit expression of these sub-grids respectively for use by step S130.

[0088] Since the value interval is the estimated range of the output value of the implicit expression of the sub-grid, it includes the threshold interval and can accurately determine that the sub-grid must be on the model (for example, very close to the outer contour of the model), or even if it is on the model, it will cross the outer contour of the model. Therefore, in step S130, the computer device selects a sub-grid in which the value interval of the implicit expression includes the threshold interval in the single-layer grid that meets the corresponding layer resolution as the key grid and fills in the output value of the implicit expression of at least one representative point, which is then used to determine the slice contours of the selected layers, that is, the slice contours of the layers of the subspace. Please continue to refer to Fig. 9 ,like Fig. 9 The 32 sub-grids after the second level gridding are all single-layer grids that meet the corresponding layer resolution (i.e., the resolution of the layer constituting the subspace V1) and among the 32 sub-grids, only the value range of sub-grid v111, sub-grid v112, sub-grid v115, sub-grid v116, sub-grid v121, sub-grid v125, sub-grid v151, sub-grid v152, sub-grid v161, and sub-grid v166 contains the threshold range, then the computer device will use sub-grid v111, sub-grid v112, sub-grid v115, sub-grid v116, sub-grid v121, sub-grid v125, sub-grid v151, sub-grid v152, sub-grid v161, and sub-grid v166 as key grids.

[0089] In one embodiment, the step of filling the output value of the implicit expression of at least one representative point in the key grid includes selecting at least one representative point in the key grid to obtain the output value of the implicit expression of the at least one representative point, and filling the output value into the corresponding position in the key grid. The representative point can be configured as the center point of the key grid and can also be configured as other position points in the key grid such as the corner points of the key grid. In one example, the step of filling the output value of the implicit expression of at least one representative point in the key grid includes selecting a representative point in the key grid to obtain the output value of the implicit expression of the representative point, and filling the output value into the position of the representative point in the key grid. Taking the representative point as the center point of the key grid as an example, the coordinates of the center point of the key grid are input into the implicit expression to obtain the output value of the implicit expression of the center point, and the output value is filled into the corresponding key grid. Please continue to refer to Fig. 9, after inputting the coordinates of the center points of sub-grid v111, sub-grid v112, sub-grid v115, sub-grid v116, sub-grid v121, sub-grid v125, sub-grid v151, sub-grid v152, sub-grid v161, and sub-grid v166 into the implicit expression respectively, the output values ​​of the implicit expression of the center points of sub-grid v111, sub-grid v112, sub-grid v115, sub-grid v116, sub-grid v121, sub-grid v125, sub-grid v151, sub-grid v152, sub-grid v161, and sub-grid v166 can be obtained and the output values ​​are filled into sub-grid v111, sub-grid v112, sub-grid v115, sub-grid v116, sub-grid v121, sub-grid v125, sub-grid v151, sub-grid v152, sub-grid v161, and sub-grid v166 respectively. In this example, the computer device can fill the output value of the implicit expression of the center point of the key grid into the position of the center point in the key grid. Although the above example is explained in detail by taking the example of selecting a representative point in the key grid to obtain the output value of the implicit expression of the representative point, and filling the output value into the key grid, it is not limited to this. In other examples, multiple representative points (two or more) can also be selected in the key grid to obtain the output values ​​of the implicit expression of the multiple representative points, and then fill the output values ​​of the implicit expression of the multiple representative points into the positions of the multiple representative points of the key grid. For example, the four corner points on the upper surface of the key grid are used as representative points, and the output values ​​of the implicit expression of the four corner points are filled into the positions of the four corner points of the key grid respectively.

[0090] It should be noted that the value filled in the key grid can also be any value with the same positive and negative sign as the output value of the implicit expression. For example, if the output value of the implicit expression of the center point of the key grid is -8, then any negative number can be directly filled in the key grid. For example, if the output value of the implicit expression of the center point of the key grid is 8, then any positive number can be directly filled in the key grid.

[0091] In one embodiment, the computer device may further use a preset algorithm to perform contour calculation on the key grid after each layer is filled to generate the slice contour of each layer. The preset algorithm may be a Marching Squares algorithm, a two-dimensional Dual Contouring algorithm, etc. It should be noted that the present application does not limit the preset algorithm, and those skilled in the art may select other linear interpolation algorithms that can realize the conversion of gridded data into slice contours based on the above examples of preset algorithms.

[0092] Since the present application only calculates the output value of the implicit expression for the key grid, the amount of calculation is reduced. Furthermore, the present application can realize the parallel execution described later under the condition of limited configuration of the computer equipment.

[0093] Steps S120 and S130 can be used to grid a subspace step by step and determine the slice contours of each layer in the subspace. In other words, steps S120 and S130 can be used to obtain the slice contours of multiple layers contained in a subspace. When the continuous multiple layers can constitute multiple subspaces, steps S120 and S130 need to be performed for the multiple subspaces to calculate the slice contours of the continuous multiple layers. Fig.10 Combined with Figure 5 , Fig.10 It is a schematic diagram showing that a plurality of continuous layers constitute two subspaces in one embodiment of the present application. As shown in the figure, the plurality of continuous layers is 7 layers, subspace V1 is composed of 4 continuous layers, and subspace V3 is composed of 3 continuous layers.

[0094] In one embodiment, when performing the step of gridding step by step and determining the slice contour of each layer in the subspace for multiple subspaces, the computer device allocates threads to the multiple subspaces respectively to perform the step-by-step gridding and determining the slice contour of each layer in the subspace in parallel. Each thread can perform the step-by-step gridding and determine the slice contour of each layer in the subspace for a subspace, thereby realizing the calculation of multiple subspaces at the same time, and the slice contour of each layer in multiple subspaces can be obtained at one time, which speeds up the calculation. For example, please continue to refer to Fig.10 , the computer device allocates a thread to each of the subspaces V1 and V3 to realize the calculation of the slice contours of each layer in the subspaces and the gridding of the subspaces V1 and V3 at the same time. In one implementation, the parallel calculation is performed by a CUDA (Compute Unified Device Architecture) software package configured on the computer device. The CUDA is a programming model of a GPU (Graphic Processing Unit). Its programming mode is single program multiple data, that is, multiple concurrent threads execute a single program to process multiple data, which greatly improves the data processing speed.

[0095] In another embodiment, the computer device may also serially perform the steps of gridding in stages and determining the slice contours of each layer in the subspace on multiple subspaces.

[0096] In some embodiments, the present application also proposes a slicing system, which can be deployed in a computer device, for example, as a software tool or software module that can process data, and it performs data processing with the help of the operating environment provided by the hardware device and / or operating system in the computer device.

[0097] See also Fig.11 , which is a module block diagram of a slicing system in an embodiment of the present application. As shown in the figure, the slicing system 1 includes a layer creation module 10, a subspace determination module 11, and a subspace slicing module 12. The layer creation module 10 is used to create a plurality of continuous layers that can completely wrap the implicit expression model, wherein the plurality of layers are respectively configured with layer resolutions, and the layer creation module 10 is also used to determine the layer resolutions of the plurality of layers based on the grid parameters of the layer plane; the subspace determination module 11 selects any number of continuous layers from the plurality of layers to form a subspace; the subspace slicing module 12 includes: a gridding and filling unit , used to perform step-by-step gridding on the subspace, including: recursively determining the value interval of the implicit expression of each subgrid of the current level to perform next-level gridding on the subgrids whose value interval contains a threshold interval, until each subgrid of the current level is a single-layer grid that meets the corresponding layer resolution; and selecting a subgrid whose implicit expression value interval contains the threshold interval as a key grid in the single-layer grid that meets the layer resolution of the corresponding layer and filling it with the output value of the implicit expression of at least one representative point; a slice contour determination unit, used to determine the slice contour of each layer based on the key grid after each layer in the subspace is filled. The subspace slicing module 12 is also used to allocate threads to multiple subspaces to perform the step-by-step gridding in parallel and determine the slice contour of each layer in the subspace.

[0098] In one embodiment, the slicing system 1 includes a layer creation module 10, a subspace determination module 11, and a subspace slicing module 12, which respectively coordinate and execute the slicing method disclosed in any of the aforementioned embodiments of the present application according to the functions described above. Figures 1 to 10 Any embodiments described in related manner will not be described in detail here.

[0099] The layer creation module 10, the subspace determination module 11, and the subspace slicing module 12 may also be implemented in software run by different types of processors. For example, a module of executable code may include one or more physical or logical blocks of computer instructions organized as objects, procedures, or functions. However, the executable files of the modules do not have to be physically located together, but may include different commands stored in different locations, which, when logically connected together, comprise the module and achieve the specified goals of the module.

[0100] Of course, a module of executable code can be one or many instructions, and can even be distributed in several different code segments, distributed in different programs, and distributed in multiple storage devices. Similarly, operational data can be identified and shown in the module, and the operational data can be embodied in any suitable form and organized in any suitable type of data structure. The operational data can be collected as a single data set, or can be distributed in different locations (including different storage devices), and can exist at least partially only as electrical signals in a system or network. When a module or a portion of a module is implemented in software, the software portion is stored on one or more computer-readable media.

[0101] The present application also provides a computer device, including a bus, a processor, a memory, and a communication interface. The processor, the memory, and the communication interface communicate with each other via the bus. The computing device may be a server, a laptop, a desktop computer, an edge device, etc., and the embodiments of the present application do not specifically limit the number of processors and memories in the computing device.

[0102] The bus can be a Peripheral Component interconnect (PCI) bus or an Extended industry Standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one line is used in the figure, but it does not mean that there is only one bus or one type of bus. The bus may include a path for transmitting information between various components of a computing device (for example, memory, processor, communication interface).

[0103] In one embodiment, the computer device is used to implement the slicing method described in any of the above embodiments. In one embodiment, the computer device is a device capable of performing digital calculations, logical processing, and information processing on data, including but not limited to: personal computers, industrial computers, tablets, smart phones, servers, server clusters, smart terminals, cloud-based server systems, etc.

[0104] See also Fig.12 , which is a schematic diagram of the structure of a computer device in an embodiment of the present application, wherein the computer device 2 includes a storage device 20 and a processing device 21 connected to the storage device 20. Furthermore, the computer device also includes a communication interface 22.

[0105] In some embodiments, the storage device 20 is used to store at least one program, and the at least one program can be executed by the processing device 21 to coordinate the storage device 20 to implement the slicing method described in any of the above embodiments. Here, the storage device 20 includes but is not limited to: Read-Only Memory (ROM), Random Access Memory (RAM), Nonvolatile RAM (NVRAM). For example, the storage device 20 includes a flash memory device or other non-volatile solid-state storage device. In some embodiments, the storage device 20 may also include a memory away from one or more processing devices 21, such as a network attached memory accessed via an RF circuit or an external port and a communication network, wherein the communication network may be the Internet, one or more intranets, local area networks, wide area networks, storage area networks, etc., or a suitable combination thereof. The memory controller may control access to the memory by other components of the device such as the CPU and peripheral interfaces.

[0106] In some embodiments, the processing device 21 includes one or more processors. The processing device 21 can be operable to perform data read and write operations with the storage device 20. The processing device 21 includes one or more general-purpose microprocessors, one or more application-specific processors (ASICs), one or more digital signal processors (Digital Signal Processors, referred to as DSPs), one or more field programmable gate arrays (Field Programmable Gate Arrays, referred to as FPGAs), or any combination thereof.

[0107] In some embodiments, the communication interface 22 includes at least one interface unit, each of which is used to output a visual interface, receive a human-computer interaction event generated according to the operation of a technician, etc. For example, the communication interface 22 includes but is not limited to: a serial interface such as an HDMI interface or a USB interface, or a parallel interface, etc. In one embodiment, the communication interface 22 also includes a network communication unit, which is a device for data transmission using a wired or wireless network, examples of which include but are not limited to: an integrated circuit including a network card, a local area network module such as a WiFi module or a Bluetooth module, a wide area network module such as a mobile network, etc.

[0108] The present application also provides a computer-readable storage medium storing at least one program, which implements the slicing method in any of the above embodiments when called and executed by a processor of a computer.

[0109] The present application also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement the slicing method in any of the above-mentioned embodiments.

[0110] If the method is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions to enable a computer device equipped with the storage medium to execute all or part of the steps of the method described in each embodiment of the present application.

[0111] In the embodiments provided in the present application, the computer storage medium provided may include a read-only memory, a random access memory, an EEPROM, a CD-ROM or other optical disk storage device, a disk storage device or other magnetic storage device, a flash memory, a USB flash drive, a mobile hard disk, or any other medium that can be used to store a desired program code in the form of an instruction or data structure and can be accessed by a computer. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if the instruction is sent from a website, a server or other remote source using a coaxial cable, an optical fiber cable, a twisted pair, a digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, optical fiber cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. However, it should be understood that computer storage media and data storage media do not include connections, carriers, signals, or other temporary media, but are intended to be non-temporary, tangible storage media. Disk and disc, as used in this application, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

[0112] In summary, the present application discloses a slicing method and system, a computer device, a computer-readable storage medium, and a computer program product. The present application selects any number of continuous layers from a plurality of continuous layers that can completely enclose the implicit expression model to form a subspace for step-by-step gridding until each subgrid of the current level is a single-layer grid that meets the corresponding layer resolution, and selects a subgrid in which the value range of the implicit expression includes the threshold range from the single-layer grid that meets the corresponding layer resolution as a key grid and fills in the output value of the implicit expression of at least one representative point therein to determine the slicing contour of each selected layer, so that In the present application, there is no need to convert the implicit expression model into a triangular mesh model for slicing first, and in the slicing process, only the output value of the implicit expression is filled in the key mesh to determine the slice contour, which reduces the amount of calculation in the slicing process and realizes efficient slicing of the implicit expression model; further, the present application can adapt to the memory configuration of different computer devices by switching between single layers or multiple layers to avoid the problem of slicing failure due to memory limitations; further, through parallel calculation of multiple subspaces, it is possible to calculate multiple subspaces simultaneously, and obtain the slice contours of each layer in multiple subspaces at one time, thereby improving the calculation speed.

[0113] The above embodiments are merely illustrative of the inventive essence of the present application and the beneficial effects obtained, and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the principles and scope of the present application. Therefore, all equivalent modifications or changes achieved by a person with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A slicing method, characterized in that: The slicing method comprises the following steps: Creating a plurality of continuous layers that can completely wrap the implicit expression model; wherein the plurality of layers are respectively configured with layer resolutions; Selecting any number of continuous layers from the multiple layers to form a subspace to grid the subspace step by step, including: recursively determining the value intervals of the implicit expression of each subgrid of the current level to grid the subgrids whose value intervals contain a threshold interval to the next level, until each subgrid of the current level is a single-layer grid that meets the corresponding layer resolution; In a single-layer grid that meets the corresponding layer resolution, a sub-grid whose implicit expression value range includes the threshold range is selected as a key grid and the output value of the implicit expression of at least one representative point is filled in it to determine the slice contours of the selected layers.

2. The slicing method according to claim 1, characterized in that: The step of creating multiple continuous layers that can completely wrap the implicit expression model includes: creating the multiple layers based on the length, width and height information of the bounding box of the implicit expression model, the grid parameters of the layer plane, and the layer spacing of the multiple layers.

3. The slicing method according to claim 2, characterized in that: Also included is the step of determining a layer resolution of the plurality of layers based on the grid parameters of the layer plane.

4. The slicing method according to claim 2, characterized in that: Creating a plurality of continuous layers that can completely wrap the implicit expression model also includes: providing a parameter configuration window for a user to input the grid parameters of the layer spacing and / or the layer plane.

5. The slicing method according to claim 4, characterized in that: The grid parameters of the layer plane include the minimum unit size of the grid of each layer or the minimum number of units of each layer in the length and width directions.

6. The slicing method according to claim 1, characterized in that: The next level of gridding is configured to traverse the length, width, and height directions of the current level of sub-grids to perform gridding in a manner of averaging the directions in which averaging can be performed.

7. The slicing method according to claim 1, characterized in that: Respectively determining the value interval of the implicit expression of each sub-grid of the current level so as to grid the sub-grids whose value interval contains a threshold value interval at the next level includes the following steps: Respectively determining the value interval of the implicit expression of each sub-grid of the current level so as to compare the threshold value interval with the value interval of each sub-grid, and gridding the corresponding sub-grid at the next level under the condition that the value interval contains the threshold value interval.

8. The slicing method according to claim 7, characterized in that: The step of respectively determining the value range of the implicit expression of each sub-grid of the current level includes: determining the value range of the sub-grid based on the diagonal vertices of the sub-grid.

9. The slicing method according to claim 8, characterized in that: The step of determining the value range of the sub-grid based on the diagonal points of the sub-grid includes: determining the body diagonal length of the sub-grid based on the diagonal vertices of the sub-grid, and determining the value range of the sub-grid based on the output value of the implicit expression of the body diagonal length and the center point of the sub-grid.

10. The slicing method according to claim 7, characterized in that: The step of respectively determining the value range of the implicit expression of each sub-grid of the current level to grid the sub-grids whose value range contains a threshold range to the next level also includes: filling the corresponding sub-grid with a numerical value outside the implicit expression model under the condition that the value range is greater than the threshold range, and filling the corresponding sub-grid with a numerical value within the implicit expression model under the condition that the value range is less than the threshold range.

11. The slicing method according to claim 10, characterized in that: The threshold interval is configured as an interval containing implicitly expressed boundary values ​​with a first threshold as an upper limit and a second threshold as a lower limit. When the lower limit value of the value interval is greater than the first threshold, it is determined that the value interval is greater than the threshold interval; when the upper limit value of the value interval is less than the second threshold, it is determined that the value interval is less than the threshold interval.

12. The slicing method according to claim 1, characterized in that: The step of gridding the subspace step by step also includes gridding the subspace for the first time to obtain a plurality of subgrids of the first gridding.

13. The slicing method according to claim 1, characterized in that: The representative point is configured as a center point of the key grid.

14. The slicing method according to claim 1, characterized in that: The step of determining the slice contours of each layer includes using a preset algorithm to perform contour calculation on the key grid after each layer is filled to generate the slice contours of each layer.

15. The slicing method according to claim 1, characterized in that: The method also includes assigning threads to the plurality of subspaces respectively to perform the step-by-step gridding in parallel and determining the slice contours of each layer in the subspace.

16. The slicing method according to claim 1, characterized in that: The arbitrary number of continuous layers includes a single layer or multiple layers.

17. A slicing system, characterized in that: The slicing system comprises: A layer creation module, used to create a plurality of continuous layers that can completely wrap the implicit expression model; wherein the plurality of layers are respectively configured with layer resolutions; A subspace determination module, used for selecting any number of continuous layers from the multiple layers to form a subspace; Subspace slicing module, including: A gridding and filling unit, for gridding the subspace step by step, comprising: recursively determining the value interval of the implicit expression of each subgrid of the current level to grid the subgrids whose value interval includes a threshold value interval until each subgrid of the current level is a single-layer grid that meets the corresponding layer resolution; and selecting a subgrid whose value interval of the implicit expression includes the threshold value interval from the single-layer grid that meets the layer resolution of the corresponding layer as a key grid and filling the subgrid with the output value of the implicit expression of at least one representative point thereof; The slice contour determining unit is used to determine the slice contour of each layer based on the key grids after each layer is filled in the subspace.

18. A computer device, characterized in that: include: A storage device for storing at least one program; A processing device, connected to the storage device, is used to call the at least one program from the storage device and implement the slicing method as described in any one of claims 1 to 16 when executing it.

19. A computer-readable storage medium, characterized in that: At least one program is stored, and when the at least one program is called and executed by a processor of a computer, the slicing method as described in any one of claims 1 to 16 is implemented.

20. A computer program product, characterized in that When the computer program product is run on a computer, the computer is enabled to execute the slicing method according to any one of claims 1 to 16.

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