Method and system for switching indication surface

Abstract

The invention relates to the technical field of computer aided design (CAD), in particular to an indicating surface switching method and system, and the method comprises the steps: displaying a three-dimensional model in a three-dimensional scene, and displaying an indicator used for indicating the three-dimensional model, the indicator comprises a plurality of indicating surfaces, and one indicating surface corresponds to one observation visual angle of the three-dimensional model; identifying a projection area of an orthogonal surface, facing the user, of the indicator in the current observation direction; the projection area refers to an image area formed when the orthogonal surface is projected on the projection plane along the projection direction; when the projection area is greater than or equal to a set area threshold value, newly adding an expansion surface at a position adjacent to the orthogonal surface; and when the projection area is smaller than a set area threshold value, hiding the expansion surface. Therefore, under the condition that the options are relatively limited, the number of the options can be expanded to a certain degree, and meanwhile the situation that the space is disordered due to the fact that the expansion surface is increased can be avoided.

Description

[0001] Priority application This application claims priority to Chinese application 2026100555900, filed on January 15, 2026, which is incorporated herein by reference in its entirety. Technical Field

[0002] This invention relates to the field of computer-aided design (CAD), and specifically to a method and system for switching indicator surfaces. Background Technology

[0003] Many computer systems process graphical data to display models of objects on a screen. For example, a computer-aided design (“CAD”) system can display a graphical model of a physical object to be designed. Typically, users need to change the view of the model displayed on the screen. For instance, in a CAD environment, users may want to be able to view the model from different angles or directions to better understand its shape, size, and construction.

[0004] Therefore, existing CAD systems may be configured with navigation tools.

[0005] I. By clicking on various faces, corners, or edges of the navigation tool, users can switch to the corresponding standard view (such as the front view, top view, etc.) with a single click. For example, US Patent Application No. 13 / 910,808 discloses a configurable viewcube controller, which uses a cube to view the camera angle of the existing scene or model in the viewport, such as viewing the scene / model from the front, back, left, right, upper left, and upper right perspectives. Another example is US Patent Application No. 11 / 729,211, which discloses a three-dimensional orientation indicator and controller, allowing users to select the corresponding view orientation by clicking on different areas of the cube. However, as 3D models become more complex, this switching method increasingly demands higher levels of abstract imagination from the user.

[0006] II. 3D Navigation via Auxiliary Markers: For example, see US Patent Application US10 / 627,974, which discloses a 3D scene orientation indicator system with scene orientation change capability. This system allows users to change the scene orientation by selecting a conical handle as an auxiliary marker. However, the visual correlation between this auxiliary marker (such as the conical handle) and the 3D model in 3D space is relatively weak. Therefore, when faced with an auxiliary 3D model, users face greater difficulty in selecting a direction (due to the increased difficulty in spatial visualization).

[0007] Third, spatial guidance can be achieved by using a scaled-down 3D model, or by placing navigation tools around the 3D model. For example, Chinese patent application CN103124986A discloses a 3D model view navigation device, which uses a cube enclosing the 3D model as the view navigation device and uses the cube's faces, edges, and vertices as the manipulated objects. See also US patent application US16 / 014,922, which discloses a graphical user interface tool for orienting a computer-aided design model. This graphical user interface tool has two operating modes: one allows users to switch views by manipulating the coordinate system (e.g., displaying X, Y, and Z axes); the other provides a transparent container to enclose the scaled-down 3D model, thereby assisting users in selecting the view direction.

[0008] Similarly, the applicant believes that if the above-mentioned guidance method is used, users will face great difficulty in spatial perception or view orientation selection when dealing with complex and unconventional 3D models (such as large building models). Therefore, there is an urgent need for a view navigation method that is easy to operate and can adapt to complex 3D scenes. Summary of the Invention

[0009] The purpose of this invention is to provide a method for switching indicator surfaces, which partially solves or alleviates the above-mentioned deficiencies in the prior art and can optimize the user experience. To solve the aforementioned technical problems, this invention specifically adopts the following technical solution: A first aspect of this invention provides a method for switching indicator surfaces, comprising the steps of: S301, displaying a three-dimensional model in a three-dimensional scene, and displaying an indicator for indicating the three-dimensional model, the indicator including multiple indicator surfaces, the multiple indicator surfaces including orthogonal surfaces, or the multiple indicator surfaces including orthogonal surfaces, edge surfaces, and vertex surfaces; and one indicator surface corresponding to an observation view of the three-dimensional model; S302, identifying the projected area of ​​the orthogonal surface of the indicator facing the user under the current observation orientation; the projected area refers to the image area formed when the orthogonal surface is projected onto the projection plane along the projection direction; S303, when the projected area is greater than or equal to a set area threshold, adding an extended surface at a position adjacent to the orthogonal surface; S304, when the projected area is less than the set area threshold, hiding the extended surface.

[0010] In some embodiments, the orthogonal surface is provided with text or graphic identifiers for indicating orientation. In some embodiments, when the indicator is a cube, the extended surface is a geometric shape constructed outward from the side of the orthogonal surface. In some embodiments, the extended surface is a geometric shape constructed outward from the side of the orthogonal surface; and / or, the extended surface is a geometric shape constructed outward from the side of the edge face. In some embodiments, the extended surface includes: a first boundary and a second boundary, the first boundary and the second boundary being connected to form the geometric shape; wherein the first boundary and the corresponding side of the orthogonal surface or the side of the edge face are adjacent or collinear, and the second boundary has at least one arc segment. In some embodiments, the visual display intensity of the extended surface is less than the visual display intensity of the orthogonal surface or the edge face. In some embodiments, the visual display intensity is defined by color depth, brightness, or opacity. In some embodiments, the geometric shape is a triangle-like or semi-circular shape.

[0011] In some embodiments, the method further includes: when a user selects the extended surface and / or the orthogonal surface, the display attributes of the extended surface and / or the orthogonal surface will change. In some embodiments, the method includes: updating the visual enhancement elements of the extended surface and / or the orthogonal surface according to the display background of the 3D scene. In some embodiments, the indicator is used to represent user spatial coordinates, and correspondingly, the method further includes: providing a plurality of azimuth planes for representing world spatial coordinates, wherein the plurality of azimuth planes are arranged around the indicator, and one azimuth plane corresponds to an observation view of the 3D model. In some embodiments, the method further includes: hiding the azimuth plane when the projected area is greater than or equal to a set area threshold.

[0012] The present invention also provides a system for switching indicator surfaces, comprising: a display module for displaying a three-dimensional model in a three-dimensional scene, and displaying an indicator for indicating the three-dimensional model, the indicator comprising multiple indicator surfaces, the multiple indicator surfaces comprising orthogonal surfaces, or the multiple indicator surfaces comprising orthogonal surfaces, edge surfaces, and vertex surfaces; and one indicator surface corresponding to an observation view of the three-dimensional model; an identification module for identifying the projected area of ​​the orthogonal surface of the indicator facing the user at the current observation position; the projected area refers to the image area formed when the orthogonal surface is projected onto the projection plane along the projection direction; an expansion module for adding an expansion surface at a position adjacent to the orthogonal surface when the projected area is greater than or equal to a set area threshold; and a hiding module for hiding the expansion surface when the projected area is less than the set area threshold.

[0013] Beneficial technical effects: For scenarios with relatively limited selectable surfaces, this invention provides an indicator that displays different surfaces in a hierarchical manner. By enhancing the visual effect of the original surface (which refers to the surface that can be clearly seen by the user under conventional perspective rules), it provides extended surfaces with weaker visual effects. These extended surfaces have different visual effects from the original surfaces, so as to guide users to quickly understand the functions of different surfaces, while reducing the visual interference that the extended surfaces may cause. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0015] Figure 1This is a schematic diagram illustrating the effect of the indicator in a second perspective state in an exemplary embodiment of the present invention; Figure 2 This is a schematic diagram showing the effect of the indicator in a first perspective state in another exemplary embodiment of the present invention; Figure 3 This is a view of an exemplary 3D model in the southwest direction; Figure 4 for Figure 3 An internal view of the 3D model shown; Figure 5 for Figure 3 The three-dimensional model shown is viewed under different field-of-view angles. Figure 6 This is a schematic diagram illustrating the interaction between the indicator surface and the azimuth surface in an exemplary embodiment. Figure 7 This is a visual comparison diagram of the indicator in the first perspective state and the normal display state; Figure 8 This is a schematic diagram showing the effect of the indicator in a first perspective state in yet another exemplary embodiment of the present invention; Figure 9a This is a schematic diagram showing the 3D model from a set of different perspectives. Figure 9b This is a schematic diagram showing the 3D model from another set of different perspectives. Figure 10 This is a schematic diagram showing the 3D model from another set of different perspectives; Figure 11 A schematic diagram showing the interior of a room under a set of different field-of-view angles; Figure 12 This is a schematic diagram showing the interior of the room under another set of different field-of-view angles; Figure 13 This is a schematic diagram showing the display of a 3D model under different field-of-view angles. Figure 14 This is a schematic diagram illustrating the combined display effect of an indicator and a 3D model in an exemplary embodiment. Figure 15 This is a schematic diagram illustrating the combined display effect of the indicator and the orientation plane in an exemplary embodiment of the present invention; Figure 16 This is a schematic diagram of the rotation axis of an exemplary indicator of the present invention; Figure 17 This is a schematic diagram of the rotation axis of another exemplary indicator of the present invention; Figure 18 This is a schematic diagram of the operating state of the indicator in another exemplary embodiment of the present invention; Figure 19 This is a schematic diagram of a method flow of an exemplary embodiment of the present invention; Figure 20 To and Figure 19 The corresponding system module diagram; Figure 21 This is a schematic diagram of a method flow according to another exemplary embodiment of the present invention; Figure 22 To and Figure 21 The corresponding system module diagram; Figure 23 This is a schematic diagram of a method flow for yet another exemplary embodiment of the present invention; Figure 24 To and Figure 23 A schematic diagram of the corresponding system modules. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] In this document, suffixes such as "module," "component," or "unit" used to denote elements are used solely for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "component," or "unit" can be used interchangeably. In this document, terms such as "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In this document, unless otherwise expressly specified and limited, terms such as "installed," "equipped with," and "connected" should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0018] In this document, "and / or" includes any and all combinations of one or more of the listed related items. "A plurality of" means two or more, i.e., it includes two, three, four, five, etc. As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4%, more typically + / -3%, more typically + / -2%, even more typically + / -1%, even more typically + / -0.5%. In this specification, certain embodiments may be disclosed in a range format. It should be understood that this "range" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of the range should be considered as having specifically disclosed all possible subranges and independent numerical values ​​within those ranges. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. The above rules apply regardless of the breadth of the range.

[0019] In this article, "standard view plane" or "standard view" refers to the various standard drawing planes (including: floor plan, side elevation, front elevation, rear elevation, southwest isometric plane, etc.) used in the industry when drawing with 3D drawing tools, such as CAD drawing tools. When a standard view plane is selected and displayed, its normal vector can be used as the screen's visual orientation, that is, the current view direction or viewing angle. The screen's visual orientation can refer to the direction the user is looking into the depth of the screen, or the orientation of the virtual camera lens. For example, the normal vector corresponding to the front elevation is called the frontal view direction (or forward viewing angle), the normal vector corresponding to the right elevation is called the right viewing direction (or right viewing angle), the normal vector corresponding to the left elevation is called the left viewing direction (left viewing angle), the normal vector corresponding to the rear elevation is called the rear viewing direction (or rear viewing angle), the normal vector corresponding to the right rear side elevation is called the right rear side direction (or right rear side viewing angle), and the normal vector corresponding to the southwest isometric plane is called the southwest isometric direction (or southwest isometric angle), etc.

[0020] For example, in CAD, a standard view refers to a view orientation preset according to engineering drawing specifications. These view orientations can be the six basic orthogonal directions of the 3D model: front, back, left, right, top, and bottom, as well as multiple isometric directions such as southwest, southeast, northeast, and northwest.

[0021] In this article, "viewpoint orientation" can be used to define the user's viewpoint direction and observation position when observing a 3D model. In other words, viewpoint orientation includes: spatial information quantified about the orientation of the user's (i.e., the observer's) "line of sight" or "virtual camera" in 3D space. For example, the viewpoint direction can refer to the angle of the user's observation viewpoint (or line of sight) in at least one planar or axial direction. For example, when the viewpoint direction is a frontal viewpoint, the view information observed by the user when facing the 3D model will be simulated on the display screen. As another example, when the viewpoint direction is a right-facing viewpoint, the view information observed by the user when standing on the right side of the 3D model and facing the 3D model will be simulated on the display screen.

[0022] In computer-aided design of 3D observation scenarios, a virtual camera is an abstract mathematical model used to define and control the view information displayed on the screen. It simulates the core parameters of a real-world camera, defining the direction of the observer's line of sight and the composition of the screen content by determining three basic elements: the observation target (i.e., the 3D model), the observation angle, and the observation position. This allows the 3D model space to be projected onto a 2D display plane, i.e., onto the display screen.

[0023] In this article, "operation plane," also referred to as "operation surface" or "indicator surface," refers to the intuitive and user-friendly planes corresponding to various standard view directions presented by the view navigation device (or indicator) when it is represented in three dimensions. For example, the six faces of a cube are called indicator surfaces. For example, each plane of a 26-sided cube (also called the first operation plane), and the eight planes of the octagonal design surrounding the 26-sided cube (also called the second operation planes). The second operation planes have two states: a working state, where each second operation plane corresponds to a standard view surface of the 3D scene or 3D model, such as a southwest isometric view; and an auxiliary state, where each second operation plane is used to assist in locating the eight hidden first operation planes (i.e., the second type of operation planes; of course, the hidden first operation planes differ depending on the viewpoint).

[0024] like Figure 6 As shown, when the first operation surface marked "front" is displayed on the display screen, the other multiple first operation surfaces are hidden. At this time, the second operation surface can be changed to an auxiliary state, such as changing to a triangle icon, to spatially indicate the hidden first operation surface.

[0025] For example, when the current viewpoint is a forward-looking view (or a frontal view) (the corresponding plane is referred to as the first type of first operating plane), the first operating planes corresponding to the left-looking view, right-looking view, upward-looking view (i.e., top-down view), and downward-looking view (i.e., bottom-up view) are hidden (the hidden planes are also referred to as the second type of first operating plane). At this time, the second operating plane is in an auxiliary state, which is used to locate the hidden first operating plane. Only when the first type of first operating plane is selected will the state of the second operating plane switch to the auxiliary state, and correspondingly, the second type of first operating plane will be hidden.

[0026] In this document, different terms such as style, display attribute, visual display intensity, or visual parameter are used to define the visual attributes of a face or edge in different embodiments. Visual attributes are essentially basic parameters used to describe the different visual effects that a face or edge presents during the display process, such as transparency or opacity, color type, color depth, or brightness, etc.

[0027] See Figures 1-24 As shown, the present invention provides a new indicator and its working method.

[0028] Example 1: It should be noted that in existing CAD products, to facilitate users' rapid observation of different faces of a 3D model, navigation tools are usually provided, such as using a hexahedron or 26-hedron as a navigation indicator. When the user clicks on one of the faces, the current 3D scene or 3D model will switch accordingly. Furthermore, to ensure that the indicator can quickly assist in positioning, the displayed face of the indicator should correspond one-to-one with the user's viewing angle, such as the viewing direction.

[0029] For example, when the user's viewing direction is straight ahead, the structural surface (or indicator surface) in the 3D model that is considered the front will face the user, and the front of the indicator (such as the indicator surface marked "front") will also face the user. Therefore, in the existing display logic, it can be noted that the display of the indicator surface and the viewing direction are highly corresponding. In other words, the relationship between the displayed indicator surface and the viewing direction is highly bound.

[0030] In stark contrast, this invention provides a technical solution to decouple the relationship between the indicator surface and the viewing direction. Specifically, this invention employs a display method where the display of the indicator surface and the display of the viewing direction are not completely synchronized. Furthermore, the applicant notes that this decoupled display solution can actually improve the spatial correlation of visual angles in complex 3D scene displays, especially when observing the interior of a model (observing the structural design of a room), thereby simplifying the user's abstract thinking.

[0031] See Figure 19As shown, the present invention provides a method for switching perspective relationships, including the following steps: S100, provides a three-dimensional model and an indicator for indicating the three-dimensional model, the indicator having multiple indicating faces, and at least one indicating face corresponding to a standard view face of the three-dimensional model; like Figure 1 As shown, the indicator can be a 26-sided cube, where all 26 faces can be used as indicator faces. Alternatively, the indicator can be a cube, where all six faces can be used as indicator faces. When the user clicks on an indicator face, the current 3D model will switch to the corresponding standard view face.

[0032] S101, when the indicator is in the first perspective state, the perspective effect of the indicator is switched according to the user's viewing angle; wherein, S101 includes: Step a) Obtain the user's viewing orientation, which includes: viewing direction, which is the angle of the user's observation viewpoint in at least one planar direction or axial direction; and observation position; Step b) Determine at least one display surface of the 3D model based on the user's viewing orientation, and designate at least one indicator surface opposite to the display surface as a primary indicator surface; Step c) Determine at least one hidden surface of the 3D model based on the user's viewing orientation, and designate at least one indicator surface opposite to the hidden surface as a secondary indicator surface; Step d) Set the display attributes of the primary indicator surface to a first style, and set the display attributes of the secondary indicator surface to a second style.

[0033] Here, the observation position refers to the current location of the user's observation point, which can be either outside or inside the 3D model. By differentiating between the first and second styles, the first-level indicator surface, which is obscured by the second-level indicator surface in the projection direction of the current viewpoint, can be made observable.

[0034] In this embodiment, a 3D model can be composed of multiple structural surfaces. Under different viewing angles, some of these structural surfaces will be displayed; therefore, these surfaces can also be called displayed surfaces. Other structural surfaces will be obscured by the displayed surfaces or located behind the observation point and thus invisible; therefore, these surfaces can also be called hidden surfaces or occluded surfaces. Specifically, the selection of displayed and hidden surfaces will be determined by the user's viewing angle, or in other words, the viewing angle of the virtual camera.

[0035] For example, with Figure 3Taking the 3D model of a house as an example, when the user's observation position (i.e., the location of the observation point) is located outside the house and the viewing direction is southwest, the external structure of the house in the southwest direction will be displayed on the screen. At this time, other external structures of the house (such as those in the northeast direction) are hidden because the view is obstructed; these are considered hidden surfaces. Specifically, a 3D model can be composed of multiple structural surfaces. For example... Figure 4 , Figure 5 Taking a room as an example, it consists of a roof, a floor, and four walls. Therefore, the roof, floor, and four walls can be considered as six structural surfaces. See also... Figure 4 When the user's viewing position is inside the house and the viewing direction is downward, the floor structure of the room will be displayed on the screen; that is, the structural surface of the floor will be displayed. The top of the room will be invisible, essentially hidden, thus concealing the structural surface of the house's top.

[0036] The first indicator 1 is now used to represent the indicator in this application, while the second indicator 2 is used to represent the indicator in the prior art. The differences and advantages of this invention will then be explained through the working modes of the first and second indicators: In the prior art, the second indicator 2 is displayed as follows: Since the user's viewing direction is from top to bottom, based on the principle that the display orientation of the second indicator and the three-dimensional model (i.e., the room) should correspond, the indicator surface marked "up" on the second indicator faces the screen. Simultaneously, the structural surface of the floor seen from top to bottom will also be displayed facing the screen.

[0037] The first indicator 1 in this application is displayed by showing the structural surface of the floor as the display surface, while the structural surface of the roof is hidden because it is obscured. At this time, the first indicator 1 hides the indicator surface marked "up" (equivalent to the secondary indicator surface), while the indicator surface marked "down" (equivalent to the primary indicator surface), which should be obscured, is displayed.

[0038] It is understandable that in some embodiments, the indicator surface marked "up" can be directly hidden, or the display attributes of the indicator surface marked "up", such as the transparency, can be increased (or the opacity can be decreased), as long as the indicator surface marked "down" can be displayed.

[0039] Therefore, this embodiment breaks the principle of consistency between the display of indicators and 3D models, instead flexibly combining the displayed structural and indicator surfaces according to the user's observation position and viewing direction. This decoupling of structural and indicator surfaces actually improves the spatial correspondence between them in complex 3D scenes. Thus, from the user's visual perspective, this indirect correspondence can actually reduce the difficulty of orientation.

[0040] For example, a typical complex 3D scene could be the interior of a house, where the user's spatial perception is relatively weak. It's worth noting that the applicant found that when a user is observing from outside the house, they can identify their location using salient features (such as adjacent buildings and the main entrance) because they are facing the overall structure of the house. However, when a user enters the house, the difficulty of identifying their location increases significantly due to the many variations in interior layout, especially when there are many rooms and the interior decoration or structure is complex.

[0041] like Figure 4 As shown, what you see inside the room is the floor, and what you see on the indicator is the side marked "down." From the user's perspective, this correspondence is highly spatially relevant. Therefore, the user can quickly recognize the spatial relationship between the current room and the indicator. Conversely, if the indicator were marked "up," although the orientation of the indicator and the room would be completely consistent, it would easily confuse the user about up and down directions, making it difficult to discern the internal orientation of the room.

[0042] For example, in some embodiments, the method includes: displaying a three-dimensional scene or three-dimensional model on a display screen; displaying a three-dimensional representation of an indicator, the three-dimensional representation including multiple indicator surfaces corresponding to different standard view surfaces of the three-dimensional scene or three-dimensional model, wherein the indicator surfaces can be used to reflect the user's coordinate space, and each indicator surface can correspond to the view direction of a standard view surface; in response to any indicator surface selected by the user, taking the view direction corresponding to the indicator surface selected by the user as the current view direction, and reorienting the three-dimensional scene or three-dimensional model to display the standard view surface of the three-dimensional scene or three-dimensional model under the current view direction.

[0043] In some embodiments, setting the display attributes of the primary indicator surface to a first style includes providing text or graphic symbols for indicating orientation on (at least one) of the primary indicator surfaces. Specifically, the text or graphic symbols are displayed on the viewing surface of the primary indicator surface. For example, in some embodiments, such as Figure 1As shown, the indicator is a 26-sided polyhedron, which includes 6 orthogonal faces, 12 edge faces, and 8 vertex faces, totaling 26 indicator faces. The text markings on the orthogonal faces can indicate directions such as up, down, front, back, left, and right.

[0044] In this invention, the indicator can have one or more perspective states. Furthermore, the indicator can switch between different perspective states. For example, when the indicator is in the first perspective state, different indicator surfaces can have different styles in at least two viewing angles. Specifically, the difference in style between the primary and secondary indicator surfaces is that the primary indicator surface, which is easily obscured, is visually highlighted to enhance the visual consistency between the indicator surface and the structural surface.

[0045] For example, in some embodiments, setting the display attributes of the secondary indicator surface to a second style includes: hiding the text or graphic identifiers used to indicate direction provided on the secondary indicator surface. For example, in some embodiments, setting the display attributes of the secondary indicator surface to a second style includes: hiding the secondary indicator surface.

[0046] Preferably, the present invention directly hides the secondary indicator surface, that is, only the primary indicator surface is retained both visually and functionally. Specifically, the primary indicator surface is in an observable and clickable state at this time. When the user clicks or drags the primary indicator surface, the 3D model will synchronously switch or rotate.

[0047] For example, in some embodiments, setting the display attributes of the primary indicator surface to a first style and setting the display attributes of the secondary indicator surface to a second style includes: setting the transparency of the primary indicator surface to a first transparency value and setting the transparency of the secondary indicator surface to a second transparency value, wherein the second transparency value is greater than the first transparency value. That is, the secondary indicator surface has greater transparency, thus reducing its occlusion effect on the primary indicator surface, allowing the user to clearly observe the occluded or hidden surface. Specifically, when the transparency of the secondary indicator surface reaches its maximum value, it is equivalent to hiding the secondary indicator surface.

[0048] Specifically, in some embodiments, the indicator is formed by a combination of multiple indicator surfaces, each indicator surface defining a normal direction, which is the direction from the culling surface (or the back surface) to the rendering surface (or the view surface). Here, the back surface refers to the surface facing away from the camera / observer's line of sight, and the view surface refers to the surface facing the camera / observer's line of sight. For example, in some embodiments, the rendering surface / view surface is a surface used to display text or graphic labels.

[0049] In some embodiments, the first style includes a normal direction. Correspondingly, setting the display attribute of the primary indicator surface to the first style includes: obtaining the user's first observation position relative to the indicator; when the first observation position is inside the indicator, setting the normal direction of the primary indicator surface to a first direction; when the first observation position is outside the indicator, setting the normal direction of the primary indicator surface to a second direction; wherein, the indicator surface includes a viewing surface and a reverse surface, and the normal direction refers to the direction from the reverse surface to the viewing surface; and for the same primary indicator surface, the first direction and the second direction are opposite.

[0050] Specifically, when the first observation position is inside the indicator, the normal direction of the primary indicator surface points inward to the inside of the indicator, while when the first observation position is outside the indicator, the normal direction of the primary indicator surface points outward to the outside of the indicator. In some embodiments, the observation position refers to the location of the virtual observation point of the virtual camera in the three-dimensional scene.

[0051] Understandably, when visually representing indicators and 3D models, the specific visual elements to be presented are determined by the user's observation position. Specifically, the observation position includes a first observation position relative to the indicator and a second observation position relative to the 3D model.

[0052] Correspondingly, the step of setting the display attributes of the primary indicator surface to a first style may include: obtaining the user's first observation position; the first observation position is the position of a first virtual observation point, which is used to simulate the relative position between the user and the indicator; when the first observation position moves from the outside of the indicator to the inside of the indicator, the normal direction of the corresponding primary indicator surface is flipped / reversed. This allows the display rules of the primary indicator surface to be consistent with visual rules.

[0053] In this embodiment, the display logic of the indicator in this invention involves a double reversal: 1) making the originally hidden first-level indicator surface visible, that is, reversing the visible and invisible surfaces; 2) for the invisible first-level indicator surface, in order to make the first-level indicator surface not only visible, but also to make the content display the same as the user's visual perception rules, the normal direction of the indicator surface is also reversed.

[0054] In other words, this embodiment not only makes the primary indicator visible by hiding the secondary indicator surface, but also flips the primary indicator surface so that the reading direction of the text labels (such as "FRONT", "BACK", "TOP") on the viewing surface of the primary indicator surface is always consistent with the user's spatial perception and reading habits in the three-dimensional scene.

[0055] For example, taking the XYZ three-axis coordinate system as an example, the reversal of the normal direction is explained as follows: When the user is outside the indicator, what is usually seen is a relatively complete indicator, i.e., a complete hexahedron. At this time, the normal direction of the indicator face, such as the one marked "back", is F(0, 0, -1). Subsequently, when the user moves from the outside of the indicator to the inside, the indicator faces marked "front", "right", and "up" are hidden, while the face marked "back" (referred to as "back") is visible. For a camera located inside the indicator, the front of the back is facing away from the camera. Therefore, from the camera's perspective, the front of the back is facing away from the camera. At this time, in order to make the text markings on the back visible and conform to conventional spatial perception, this embodiment modifies the normal direction of the back to (0, 0, 1). At this time, the reversal of the normal direction allows the viewing face of the back (i.e., the face marked with the text "back") to face the camera lens.

[0056] Understandably, in a CAD 3D navigation control system, the normal direction defines the correspondence between the indicator and the user's viewpoint: the surface pointed to by the normal direction is the viewpoint for the user, and the user / camera's line of sight always travels along the reverse projection of the normal direction. In other words, the normal direction determines the camera's placement.

[0057] Preferably, the 3D model and the indicator surface have the same perspective parameters. Perspective parameters include: field of view (FOV) and / or focal length. The FOV determines the extent of the virtual world that the observer / camera can capture at a time. In 3D software, it is typically represented by an angle (e.g., 60°). A larger angle results in a wider view of the scene, but objects at the edges will exhibit a fisheye-like distortion; a smaller angle makes the scene appear more focused, like being viewed through a telescope, with less perspective distortion. The focal length determines the camera lens's angle of view. Short focal lengths (such as wide-angle lenses) offer a wide field of view and strong perspective (more exaggerated perspective effects); long focal lengths (such as telephoto lenses) offer a narrow field of view and weak perspective (objects are compressed). In 3D software, adjusting the focal length essentially simulates which lens the observer is using, directly controlling the intensity of perspective.

[0058] In this embodiment, ensuring that the 3D model and the indicator surface have the same perspective parameters aims to improve the consistency of the spatial visual effect between the 3D model and the indicator surface, facilitating users to quickly select the indicator surface through simple abstract thinking. In some embodiments, users may be allowed to manually modify the perspective parameters. For example, the method includes: receiving a perspective parameter update signal from the user, and updating the perspective parameters of the indicator and / or the 3D model according to the perspective parameter update signal.

[0059] Understandably, the display of the 3D model is also determined based on the observation position. This observation position may also include a second observation position of the user relative to the 3D model, which defines the location of a second virtual observation point.

[0060] In some embodiments, the method further includes the steps of: acquiring a switching signal input by the user; and setting the perspective state of the indicator according to the switching signal. In this embodiment, the user can manually switch the perspective state of the indicator to a first perspective state or a second perspective state.

[0061] In some embodiments, the method further includes the steps of: acquiring the observation position of the user's observation point; determining whether the observation position is located inside the three-dimensional object; and if so, switching or maintaining the indicator in a first perspective state. It is understood that the first perspective state can refer to a display state simulating a user entering the interior of the indicator. Specifically, in some embodiments, the method includes the step of: acquiring a second observation position, and when the second observation position is located inside the three-dimensional object (e.g., inside a room), it is preferably recommended to switch the indicator to the first perspective state.

[0062] In some embodiments, a 3D object can refer to a 3D model. Alternatively, in some embodiments, a 3D object can also refer to a sub-model within a 3D model. In some embodiments, a 3D model can be obtained by combining multiple sub-models. For example, a tile can be considered a sub-model. For example, in some embodiments, taking an architectural model as an example, multiple floors (which can be considered multiple sub-models) are nested within the overall shell of the building. Furthermore, multiple rooms (which can also be considered a sub-model) can be nested within a single floor. Further still, one or more pieces of furniture, such as tables and chairs (which can also be considered a sub-model), can be placed within a room.

[0063] In other words, in some embodiments, when it is detected that the user's observation point has entered the interior of the three-dimensional model, it can preferably help the user set or switch the indicator to the first perspective state.

[0064] In some embodiments, the method includes: setting the indicator to a second perspective state; wherein, when the indicator is in the second perspective state, the image height of the indicator on a two-dimensional projection plane (such as a display screen) gradually decreases as the indicator moves away from the observation point. That is, the second perspective state refers to the indicator having a near-large and far-small display effect, see [link to previous section]. Figure 1 As shown. In some embodiments, when the indicator is in a second perspective state, the visual presentation of the indicator (such as the display of the indicator surface) follows the line-of-sight occlusion rules in geometric optics, such as... Figure 1As shown, when a user is viewing the front of the FORNT marker, the back is not visible according to the line-of-sight occlusion rules of geometric optics.

[0065] In some embodiments, the indicator surface includes: multiple orthogonal surfaces, multiple edge surfaces, and multiple vertex surfaces; and each of the orthogonal surfaces, edge surfaces, and vertex surfaces corresponds to a standard view surface; the orthogonal surfaces and / or the edge surfaces are set to a restricted rotation mode, and in the restricted rotation mode, the orthogonal surfaces and / or the edge surfaces are provided with a preset axis; correspondingly, the method further includes: when it is detected that the user keeps selecting the orthogonal surface and / or the edge surface and triggers a drag signal, selecting the corresponding preset axis as the rotation axis, and determining rotation parameters according to the drag signal, the rotation parameters including at least one of the following: rotation direction, rotation speed, and rotation angle; causing the user's observation orientation to rotate around the rotation axis according to the rotation parameters, and switching the display data of the three-dimensional model according to the change in the observation orientation.

[0066] Example 2: See Figure 20 As shown, the present invention also provides a perspective relationship switching system, comprising: a display module for providing a three-dimensional model and an indicator for indicating the three-dimensional model, the indicator having multiple indicator surfaces, and at least one indicator surface corresponding to a standard view surface of the three-dimensional model; a first perspective module for switching the perspective effect of the indicator according to the user's viewing angle when the indicator is in a first perspective state; wherein, the first perspective module is further configured to: obtain the user's viewing angle, the viewing angle including: the angle of the user's observation viewpoint in at least one planar direction or axial direction; determine at least one display surface of the three-dimensional model according to the user's viewing angle, and designate at least one indicator surface opposite to the display surface as a primary indicator surface; determine at least one hidden surface of the three-dimensional model according to the user's viewing angle, and designate at least one indicator surface opposite to the hidden surface as a secondary indicator surface; set the display attributes of the primary indicator surface to a first style, and set the display attributes of the secondary indicator surface to a second style, so that the primary indicator surface covered by the secondary indicator surface in the projection direction of the current viewing angle is observable.

[0067] Example 3: See Figure 21 As shown, the present invention also provides an interaction method, including: S201, Display a 3D model in a 3D scene, and display an indicator for indicating the 3D model. The indicator includes: multiple connected orthogonal faces, multiple edge faces, and multiple vertex faces; and each orthogonal face, edge face, and vertex face corresponds to a viewing angle (such as a standard view) of the 3D model; the orthogonal face and / or the edge face is set to a restricted rotation mode, and the orthogonal face and / or the edge face is provided with a preset axis in the restricted rotation mode; S202, When it is detected that the user keeps selecting the orthogonal face and / or the edge face and triggers a drag signal, select the corresponding preset axis as the rotation axis, and determine the rotation parameters according to the drag signal. The rotation parameters include at least one of the following: rotation direction, rotation speed, and rotation angle; S203, Make the user's viewing position rotate around the rotation axis according to the rotation parameters, and switch the display data (or view / view content) of the 3D model according to the change in the viewing position.

[0068] In this embodiment, the restricted rotation mode refers to the fact that when a user selects an orthogonal face or an edge face for rotation, its rotation axis is a fixed preset axis. In some embodiments, the preset axis of the orthogonal face is perpendicular to the orthogonal face and passes through the central region of the orthogonal face. For example, in some embodiments, the orthogonal face includes: front, back, left, right, top, and bottom. In this case, when the user selects the front and performs a drag operation, the indicator rotates around the preset axis on the front (see...). Figure 17 The indicator (as shown) rotates synchronously with the 3D model. Visually, the front of the 3D model remains visible, only shifting clockwise or counter-clockwise as the user drags it. In some embodiments, the preset axis of the edge face is parallel to the edge face; see [reference]. Figure 16 As described above. For example, in some embodiments, taking a house model as an example, when a user selects an edge face, it is equivalent to clicking on the side of the house (such as the intersection of two walls), so that the house can be dragged to rotate along the side.

[0069] In this embodiment, by restricting the switching of specific operating surfaces, the sense of spatial clutter can be reduced to some extent.

[0070] In some embodiments, the vertex face is set to a free rotation mode. Correspondingly, before S203, the method further includes: when it is detected that the user keeps selecting the vertex face and triggers a drag signal, determining a rotation path according to the drag signal and determining a rotation axis according to the rotation path; determining rotation parameters according to the drag signal, the rotation parameters including at least one of the following: rotation direction, rotation speed, and rotation angle.

[0071] For example, in some embodiments, a two-dimensional movement trajectory can be projected onto a trackball to form a three-dimensional movement trajectory, and the rotation axis and rotation parameters can be determined based on the three-dimensional movement trajectory. In some embodiments, the rotation parameters can be determined by the user's drag signal. For example, the coordinates of the user's operation point can be recorded based on the drag signal, and the rotation direction and rotation speed can be determined based on the coordinates.

[0072] In some embodiments, the method further includes: in response to a first switching signal input by a user, setting all faces of the indicator to a free rotation mode.

[0073] The free rotation mode can play an important role in the process of reviewing the spatial experience: For example, engineers, such as architects / interior designers, will focus on the human spatial experience during the review process. Specifically, they need to assess people's visual perception and movement experience within the space. In this case, engineers need to walk freely inside or around the building, simulating changes in perspective as they move through it, much like carrying a camera. For instance, they might check the visual permeability from the entrance to the lobby, or evaluate the spatial surprise created by a corner. Free movement provides a framework for handling these continuous, non-linear changes in perspective.

[0074] For example, an MEP / structural engineer might need to locate a complex piping conflict point in a densely packed equipment area (such as a basement machine room or within a suspended ceiling). The engineer first locates the general area using standard views, but to see exactly where the three pipes are and how they intersect, they must freely rotate their viewpoint to "drill" into the intersection and observe from the angle that best reveals the overlapping relationship. This optimal angle is usually arbitrary and non-standard.

[0075] Specifically, this invention selects the orthogonal faces and edge faces with the largest visual area and the highest observation probability as the restricted rotation mode, and the vertex faces with the smallest visual area as the free rotation mode. This rotation mode, which combines restricted and free rotation, can greatly improve the observation efficiency of users when observing large 3D models such as houses.

[0076] For example, during the 3D model drawing process, especially in the later stages or after completion, engineers will review and confirm the contents of the 3D model drawings. During this review, it is often necessary to quickly browse the view information from different perspectives of the 3D model. However, the applicant has noticed that, in order to achieve efficient review, engineers need to quickly locate the view they wish to observe.

[0077] The restricted and free rotation mode provided by this invention can effectively improve the observation efficiency of engineers. The reasons are as follows: 1) Orthogonal surfaces and edge surfaces with large visual area and high observation probability are set to have fixed preset axes. Orthogonal surfaces correspond to the standard six views of the 3D model, while edge surfaces correspond to the isometric views of the 3D model.

[0078] Therefore, the views corresponding to orthogonal planes and edge faces are usually the main views of the 3D model, that is, the views that engineers are likely to observe first or frequently switch during the review process. At the same time, these types of views often have the characteristics of easy orientation selection or spatial visualization. For example, engineers can quickly select the front or back of a building using the orientation indicators. Therefore, in this embodiment, orthogonal planes and edge faces are considered as planes with a high probability of observation.

[0079] Furthermore, the applicant noted that orthogonal planes and edge faces have a high probability of observation, meaning that engineers are more likely to have a specific observation target when selecting orthogonal planes or edge faces. Even with some restrictions on the engineer's rotation operations, it will not significantly limit the observation needs or impose an operational burden.

[0080] For example, taking the orthogonal plane-based limited rotation mode as an example, it allows the main view information in the rotating image (such as the view planes corresponding to the orthogonal planes in the model) to be preserved and continuously displayed on the screen during rotation. At the same time, the surrounding structure of the main view can be presented through rotation, so that users can observe it from all angles.

[0081] For example, consider the limited rotation mode of the edge face, which allows the indicator to rotate around a preset axis parallel to the edge face. The 3D model will then rotate synchronously with the indicator. From an engineer's perspective, the 3D model can rotate along its sides (e.g., along the sides of a house, such as the line formed by the intersection of two walls). Therefore, engineers can quickly and systematically browse the surrounding structure of the 3D model.

[0082] 2) Set the vertex face with the smallest visual area to free rotation mode, that is, it can have a rotation axis in any direction.

[0083] In this setting mode, engineers must intentionally and precisely click on the vertex face to trigger the free rotation mode. This integrates both free rotation and restricted rotation functions on a single indicator, while preventing accidental activation of free rotation mode during restricted rotation.

[0084] Furthermore, the vertex face, as the intersection of three edge faces and three orthogonal faces, is highly reasonable in spatial representation. That is, when engineers observe beyond the conventional standard view, they can freely explore through the unconstrained vertex face, deviating from the main orthogonal or axial directions (i.e., corresponding to orthogonal faces or edge faces).

[0085] From another perspective, this invention integrates a cooperative rotation mode that prioritizes fixed positioning while allowing for flexible rotation. This cooperative rotation mode, prioritizing fixed positioning while allowing for flexible rotation, can coordinate the needs for both precise and flexible positioning to a certain extent.

[0086] It should be noted that both precise positioning and unpredictable flexible positioning are crucial during the drawing review process. This invention uses a fixed rotation axis for orthogonal or edge faces with large visual areas and high observation probabilities, and an arbitrary rotation axis for vertex faces with small visual areas and random observation probabilities. This allows for the simultaneous fulfillment of both precise and flexible positioning needs. Furthermore, this precise and flexible positioning approach avoids potential conflicts in understanding or operation when spatially allocated.

[0087] On the one hand, from a visual perspective, orthogonal or edge faces, with their larger visual area, correspond to mainstream view planes in terms of functional positioning. This means they offer more universality and are easier for engineers to remember. Therefore, when engineers need to perform relatively regular and fixed view switching or rotation, they can quickly achieve this by dragging orthogonal or edge faces. Conversely, while vertex faces also correspond to preset view planes, these vertex faces often have lower switching requirements and are more difficult to remember (understandably, the difficulty for engineers to abstractly imagine or choose the front or back in space is far lower than the difficulty of imagining vertex faces).

[0088] On the other hand, from an operational perspective, users must make more precise selections to enter the free rotation mode, thereby reducing the interference caused by misoperation (especially incorrect switching to the free rotation mode).

[0089] For example, engineers often perform rapid and continuous operations with a mouse during the review of drawings. Incorrectly switching rotation modes can reduce the smoothness of their operation. However, when using the restricted and free cooperative rotation mode provided by this invention, the probability of misoperation can be reduced to some extent through visual and functional collaborative classification design. Furthermore, even if a switching error occurs, in this cooperative rotation mode, it is more likely that the automatic rotation mode should be selected, but the restricted rotation mode is accidentally activated. In this case, because the rotation amplitude (or screen rotation) in the restricted rotation mode is relatively small, it is less likely to create excessive spatial confusion, thus minimizing user interference.

[0090] It is understandable that even engineers with extensive software experience are prone to operational errors during rapid operations. To address this unavoidable human error, the restricted and free cooperative rotation mode provided by this invention minimizes the probability of accidentally switching to free rotation mode by limiting the difficulty of switching from automatic rotation mode. Therefore, even in the event of an accidental operation, its impact on the user is relatively small.

[0091] Therefore, this cooperative rotation mode, which prioritizes restriction and supplements freedom, is more conducive to helping engineers maintain a highly smooth operating state when conducting rapid review of 3D models.

[0092] As a preferred embodiment, the present invention provides an indicator that combines a first perspective state mode and a rotation mode. For example, in some embodiments, the indicator surface includes: a plurality of orthogonal surfaces, a plurality of edge surfaces, and a plurality of vertex surfaces; and each of the orthogonal surfaces, the edge surfaces, and the vertex surfaces corresponds to a standard view surface; the orthogonal surfaces and / or the edge surfaces are set to a restricted rotation mode, wherein the orthogonal surfaces and / or the edge surfaces are provided with a preset axis in the restricted rotation mode; correspondingly, the method includes: When it is detected that the user has kept the orthogonal surface and / or the edge surface selected and a drag signal is triggered, the corresponding preset axis is selected as the rotation axis, and the rotation parameters are determined according to the drag signal. The rotation parameters include at least one of the following: rotation direction, rotation speed, and rotation angle; so that the user's observation position rotates around the rotation axis according to the rotation parameters, and the display data of the three-dimensional model is switched according to the change of the observation position.

[0093] In some embodiments, the multiple faces of the indicator can be divided into three types: type I faces, type II faces, and type III faces. Type I and type II faces are configured with restricted rotation, while type III faces are configured with free rotation. In some embodiments, the indicator may include six faces, such as a cube. Specifically, the multiple faces of the cube can be divided into three types: type I faces, type II faces, and type III faces. Type I and type II faces are configured with restricted rotation, while type III faces are configured with free rotation. See also Figure 18 As shown, a face can be classified into three types: Type I, Type II, and Type III. Specifically, the central region 11 of the face is defined as a Type I face, the side region 12 of the face is defined as a Type II face, and the vertex region 13 of the face is defined as a Type III face.

[0094] For example, in some embodiments, a boundary line can be provided between any two types of faces to facilitate user differentiation of face categories. In other embodiments, adjacent types of faces can employ different display formats. For instance, the display format can be defined by color or brightness. Specifically, different types of faces have different colors. For example, in some embodiments, when a user selects a face, the selected face can be highlighted. Highlighting the display means adjusting the display format of the face, such as illuminating it, to facilitate accurate face selection by the user.

[0095] In some embodiments, the indicator includes at least 26 faces. In some embodiments, the indicator includes at least 6 orthogonal faces, 12 edge faces, and 8 vertex faces. It is understood that when the indicator is a 26-sided polyhedron, the orthogonal faces, edge faces, and vertex faces are considered as Class I faces, Class II faces, and Class III faces, respectively.

[0096] In some embodiments, the step of indicating a selected face includes: when the user's operation point is located in the area of ​​one of the faces, a trigger signal is emitted via a trigger, indicating that the user has selected the face. The trigger is a user input device used to receive the user's spatial displacement operation to generate a control signal for controlling changes in the view of the 3D model / indicator. For example, the trigger can be a mouse or a touchscreen (e.g., the user can operate the touchscreen with a finger or stylus), and clicking the trigger can be considered as emitting a trigger signal. See, for example, [link to previous document]. Figure 18 As shown, when the user's cursor falls on one of the indicator surfaces, the color of that surface can be changed to indicate the selected area to the user. In some embodiments, the method further includes the step of: when the trigger signal is stopped, it indicates that the user has stopped selecting the indicator surface.

[0097] In some embodiments, a fixed amplitude is used to determine the rotation parameter based on the drag signal, which includes the steps of: calculating the drag angle or drag distance of the user operation based on the drag signal; when the drag angle or drag distance belongs to a set drag angle range or drag distance range, at least one standard rotation angle is generated as a rotation parameter, wherein the standard rotation angle has a set rotation amplitude.

[0098] In other words, in this embodiment, when the user drags the indicator to switch between 3D models or 3D scenes, it has a relatively fixed rotation range, i.e., it has a certain regularity. This regular visual scene switching mode is also helpful in assisting users to perform regular and rhythmic image viewing operations.

[0099] For example, the process of generating rotation parameters can be as follows: Obtain the trajectory data of the user's operation point (e.g., trajectory data consists of continuous coordinates and timestamps), for example, the two-dimensional movement trajectory of the mouse. The computer assumes that the indicator or three-dimensional model is enclosed within a unit sphere (called a "track sphere"), and the trajectory data will also be projected onto the sphere. For example, the two-dimensional movement trajectory (x, y) of the mouse is transformed into a three-dimensional spatial curve on the sphere. Further, the rotation direction, such as clockwise or counterclockwise, can be determined based on the movement trajectory. For example, the rotation angle can be determined based on the distance of the three-dimensional spatial curve. It is understood that the specific rules for calculating the rotation parameters can be set by the user, and this invention does not impose any restrictions on this.

[0100] Correspondingly, this embodiment also provides an interactive system, such as... Figure 22 As shown, it includes: a display module for displaying a 3D model in a 3D scene, and displaying an indicator for indicating the 3D model, the indicator including: multiple orthogonal faces, multiple edge faces, and multiple vertex faces connected together; and each orthogonal face, edge face, and vertex face corresponds to a viewing angle of the 3D model; the orthogonal face and / or the edge face is set to a restricted rotation mode, and the orthogonal face and / or the edge face is provided with a preset axis in the restricted rotation mode; a recognition module for selecting the corresponding preset axis as the rotation axis when it is recognized that the user has kept the orthogonal face and / or the edge face selected and a drag signal is triggered, and determining the rotation parameters according to the drag signal, the rotation parameters including at least one of the following: rotation direction, rotation speed, and rotation angle; and a switching module for rotating the user's viewing position around the rotation axis according to the rotation parameters, and switching the display data of the 3D model according to the change in the viewing position.

[0101] Example 4: See Figure 23 As shown, the present invention also provides a method for switching indicator surfaces, including the following steps: S301, displaying a three-dimensional model in a three-dimensional scene, and displaying an indicator for indicating the three-dimensional model, the indicator including at least one orthogonal surface, and one orthogonal surface corresponding to an observation view of the three-dimensional model; for example, an observation view may correspond to a preset standard view surface; S302, identifying the projected area of ​​the orthogonal surface of the indicator facing the user under the current observation orientation; the projected area refers to the image area formed when the orthogonal surface is projected onto the projection plane along the projection direction; S303, when the projected area is greater than or equal to a set area threshold, adding an extended surface at a position adjacent to the orthogonal surface; S304, when the projected area is less than the set area threshold, hiding the extended surface.

[0102] In this embodiment, the size of the projected area is defined using 0-1. See also Figure 15 As shown, the indicator includes 26 faces, such as front, back, top, bottom, left, right, etc. When the user selects the front, the indicator rotates so that the front faces the display screen, and the projected area of ​​the front is 1. At the same time, the projected area of ​​the top is 0 (i.e., less than the set area threshold), and the top is invisible and unselectable. In order to increase the number of options from a single viewpoint, extended faces can be formed by extending outward from the edges of the four side faces.

[0103] Furthermore, in a preferred embodiment, the visual display intensity of the extended surface is lower than that of the edge surface or orthogonal surface. A higher visual display intensity indicates that the corresponding surface has a clearer or more prominent visual effect in the current display state. Specifically, the visual display intensity can be determined by data display parameters, such as brightness, color, or transparency. Generally, higher brightness results in higher visual display intensity. Alternatively, darker colors result in higher visual display intensity. Conversely, lower transparency results in higher visual display intensity. And also, higher opacity results in higher visual display intensity.

[0104] For example, in some embodiments, the visual intensity of the boundary lines of the extended surface is lower than that of the boundary lines of the edge surface or orthogonal surface. Specifically, in some embodiments, the extended surface does not have boundary lines, so that when a user observes the indicator on the display screen, it is easier to directly observe the selected surface, such as the front. This design of different visual intensity reduces the interference of the newly added extended surface on the user's line of sight.

[0105] In summary, for scenarios with relatively limited selectable surfaces, this invention provides an indicator that displays different surfaces in a hierarchical manner. By enhancing the visual effect of the original surface (which refers to the surface that can be clearly seen by the user under conventional perspective rules), it provides extended surfaces with a weaker visual effect. These extended surfaces have a different visual effect from the original surface, so as to guide the user to quickly understand the function of different surfaces, while reducing the visual interference that the extended surfaces may cause.

[0106] In some embodiments, the orthogonal surface is provided with markings for indicating orientation, such as text or graphic markings. In some embodiments, the extended surface does not have text or graphic markings indicating orientation. Alternatively, in some embodiments, the extended surface may have markings indicating orientation, but the visual intensity of the markings on the extended surface is less than the visual intensity of the markings on the original surface (such as the orthogonal surface). For example, the text color on the extended surface is lighter than the text color on the original surface.

[0107] In some embodiments, when the indicator is a cube, the extended face is a geometry constructed outward from the sides of the orthogonal face. In some embodiments, the indicator further includes: edge faces for connecting multiple orthogonal faces, correspondingly, the extended face is a geometry constructed outward from the sides of the edge faces. In some embodiments, the extended face and the orthogonal face have different display properties, including: color or transparency.

[0108] In some embodiments, the method further includes: when a user selects the extended surface and / or the orthogonal surface, the display attributes of the extended surface and / or the orthogonal surface will change. In some embodiments, the method further includes: switching the display attributes of the extended surface and / or the orthogonal surface according to the display background of the 3D scene.

[0109] In some embodiments, the indicator is used to represent user space coordinates. Correspondingly, the method further includes: providing a plurality of azimuth planes, wherein the plurality of azimuth planes are arranged around the indicator, and one azimuth plane corresponds to an observation view of the three-dimensional model. In some embodiments, the azimuth plane (or second operating plane) can be used to represent world space coordinates, in which case the indicator plane (or first operating plane) can be used to represent user space coordinates. In some embodiments, the method further includes: hiding the azimuth plane when the projected area of ​​one of the orthogonal planes is greater than or equal to a set area threshold. Figure 15 As shown, when the orthogonal plane, such as the projected area in front, is small, an azimuth plane can be provided to be displayed synchronously with the indicator. For example, eight azimuth planes can be set to surround the indicator. These eight azimuth planes can be used to represent the eight directions: east, southeast, south, southwest, west, northwest, north, and northeast. Furthermore, when the azimuth planes are hidden, extended planes can be displayed as a backup.

[0110] In some embodiments, the display attributes of the indicator surface can be arbitrarily set, such as color, brightness, or transparency. For example, the fill color of the indicator surface can be changed to improve display clarity against different backgrounds. An outline can be added to the indicator surface (i.e., darkening the edge line color or increasing brightness) to improve display clarity against backgrounds of varying shades. In some embodiments, when the 3D model undergoes significant transitions, a transition effect can be added to allow the user to better perceive spatial orientation through the transitional rotation of the 3D model. In some embodiments, the indicator can be used to represent user coordinates, and the eight second operation surfaces below the indicator can be used to represent world coordinates. In some embodiments, a menu bar is also displayed near the indicator, the menu bar having at least one function area, and each function area may include at least one extended function option.

[0111] In some embodiments, the extended surface includes: a first boundary and a second boundary, the first boundary and the second boundary being connected to form the geometry; wherein the first boundary and the side edge of the corresponding orthogonal surface or the side edge of the edge surface are arranged adjacently or collinearly, and at least one arc is provided on the second boundary.

[0112] In some embodiments, the visual display intensity is defined by color depth, brightness, or opacity. In some embodiments, the geometry is a triangular or semi-circular shape. A triangular shape refers to a geometry with three sides (or boundaries). Any two sides of this geometry are connected by a smoothly transitioning arc (or curve). That is, a triangular shape can have a shape similar to a triangle, but without sharp vertices. For example, see... Figure 15 As shown, the triangle-like structure includes: a first boundary (which is collinear with the side edges of the edge face), and a second boundary, which includes: two line segments, such as straight lines, connected to the first boundary, and the two straight lines are connected by an arc.

[0113] A semicircle-like shape is a geometric figure formed by connecting a continuous, smooth arc (equivalent to a second boundary) with a straight line (equivalent to a first boundary). For example, a semicircle-like shape can refer to a semicircle, or a geometric figure of a semicircle.

[0114] It is worth noting that this invention weakens the visual effect of the extended surface through a comprehensive setting of visual parameters and geometric shapes. Specifically, reducing the visual display intensity prevents the newly added extended surface from being too prominent, while the use of gentle curve settings further reduces the attention drawn to the extended surface in spatial display. Preferably, the extended surface is only enhanced when the user's operation point falls on it, to assist the user in accurate positioning.

[0115] Therefore, this two-dimensional hierarchical display scheme of the present invention can expand the number of options to a certain extent when the number of options is relatively limited, while avoiding spatial clutter caused by increasing the number of expanded surfaces. From another perspective, this hierarchical display scheme also lies in differentiating the priority of options for different types of surfaces.

[0116] For example, in the same way Figure 15 For example, when a user selects the foreground, the foreground will be highlighted in the subsequent process (e.g., the foreground will be pointed at the user), and the corresponding face of the 3D model will be displayed synchronously as the main view. At this stage, it is preferable to assume that the user pays more attention to the main view. Even if the user needs to switch to other views, the user will be guided to switch gradually, such as by selecting edge faces or vertex faces.

[0117] Furthermore, if a user believes that the surface displayed by the indicator cannot meet their switching needs, they may leave the operation point in the area surrounding the indicator. In this case, when the operation point is detected in the area of ​​one of the extended surfaces, it is assumed that the user has currently selected that extended surface. In some embodiments, the duration of the user's stay in the area of ​​the extended surface can be detected, and the extended surface will only be displayed if the stay time exceeds a preset time threshold.

[0118] See Figure 24 As shown, the present invention also provides a system for switching indicator surfaces, comprising: a display module for displaying a three-dimensional model in a three-dimensional scene, and displaying an indicator for indicating the three-dimensional model, the indicator comprising multiple indicator surfaces, the multiple indicator surfaces comprising orthogonal surfaces, or the multiple indicator surfaces comprising orthogonal surfaces, edge surfaces, and vertex surfaces; and one indicator surface corresponding to an observation view of the three-dimensional model; an identification module for identifying the projected area of ​​the orthogonal surface of the indicator facing the user under the current observation position; the projected area refers to the image area formed when the orthogonal surface is projected onto the projection plane along the projection direction; an expansion module for adding an expansion surface at a position adjacent to the orthogonal surface when the projected area is greater than or equal to a set area threshold; and a hiding module for hiding the expansion surface when the projected area is less than the set area threshold.

[0119] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the methods or steps of any of the above embodiments. The present invention also provides a computer program product comprising computer program instructions, wherein, when executed by a computer, the computer program instructions cause the computer to perform the methods or steps as described in any of the embodiments. It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware, but in many cases the former is a preferred implementation. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a computer terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention. The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for switching an indicator surface, characterized in that, Including the following steps: S301, Display a three-dimensional model in a three-dimensional scene, and display an indicator for indicating the three-dimensional model, the indicator including multiple indicator faces, the multiple indicator faces including orthogonal faces, or the multiple indicator faces including orthogonal faces, edge faces and vertex faces; and one indicator face corresponds to a viewing angle of the three-dimensional model; S302, Identify the projected area of ​​the orthogonal plane of the indicator facing the user under the current observation position; the projected area refers to the image area formed when the orthogonal plane is projected onto the projection plane along the projection direction; S303, when the projected area is greater than or equal to a set area threshold, an extended surface is added at a position adjacent to the orthogonal surface; S304, when the projected area is less than the set area threshold, the extended surface is hidden.

2. The switching method according to claim 1, characterized in that, The orthogonal surface is provided with textual or graphic markings for indicating orientation; and / or, when the indicator is a cube, the extended face is a geometric shape constructed outward from the side of the orthogonal surface.

3. The switching method according to claim 1, characterized in that, The extended surface is a geometric shape constructed outward from the side of the orthogonal surface; and / or, the extended surface is a geometric shape constructed outward from the side of the edge surface.

4. The switching method according to claim 2, characterized in that, The extended surface includes a first boundary and a second boundary, which are connected to form the geometry; wherein the first boundary and the side of the corresponding orthogonal surface or the side of the edge surface are arranged adjacently or collinearly, and at least one arc is provided on the second boundary.

5. The switching method according to claim 3, characterized in that, The visual display intensity of the extended surface is less than that of the orthogonal surface or the edge surface.

6. The switching method according to claim 5, characterized in that, The visual display intensity is defined by color depth, brightness, or opacity; And / or, the geometric shape is a triangle-like or semi-circular shape.

7. The switching method according to claim 1, characterized in that, Also includes: When the user selects the extended surface and / or the orthogonal surface, the display properties of the extended surface and / or the orthogonal surface will change; And / or, the method includes: updating the visual enhancement elements of the extended surface and / or the orthogonal surface according to the display background of the three-dimensional scene.

8. The switching method according to claim 1, characterized in that, The indicator is used to represent user space coordinates, and correspondingly, the method further includes: Multiple azimuth planes are provided to represent world space coordinates, and the multiple azimuth planes are arranged around the indicator, with one of the azimuth planes corresponding to an observation view of the three-dimensional model.

9. The switching method according to claim 8, characterized in that, Also includes: When the projected area is greater than or equal to a set area threshold, the azimuth plane is hidden.

10. A switching system for an indicator surface, characterized in that, include: A display module is used to display a 3D model in a 3D scene, and to display an indicator for indicating the 3D model. The indicator includes multiple indicator faces, which may include orthogonal faces, or multiple indicator faces may include orthogonal faces, edge faces, and vertex faces; and one indicator face corresponds to a viewing angle of the 3D model. The recognition module is used to recognize the projected area of ​​the orthogonal plane of the indicator facing the user at the current observation position; the projected area refers to the image area formed when the orthogonal plane is projected onto the projection plane along the projection direction; An extension module is used to add an extension surface at a position adjacent to the orthogonal surface when the projected area is greater than or equal to a set area threshold. A hiding module is used to hide the extended surface when the projected area is less than the set area threshold.

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