Method and system for generating virtual road map of predictive redirection controller

Abstract

The invention belongs to the technical field of virtual reality redirection, and provides a method and system for generating a virtual road map of a predictive redirection controller, and the method comprises the steps: carrying out the curve polygon subdivision of a given virtual scene, and calculating a shortest path tree of a current position of a user in the scene through a shortest path tree algorithm; performing skeleton processing on the given virtual scene to obtain a polygonal skeleton; calculating a visible polygonal area of the current position of the user based on the shortest path tree; extracting virtual road points according to the intersection points of the visible polygonal area and the polygonal skeleton; fitting a path between adjacent virtual road points by using a clothoid; and judging whether the current road point depth meets the given depth or not, and if not, repeatedly fitting the next virtual road point as the current position of the user until a virtual road map meeting the given depth is generated. According to the method, a prediction redirection controller virtual road map generation scheme of a curve boundary complex scene can be supported, and the problem that the application range of a prediction redirection controller in the prior art is small is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of virtual reality redirection, and relates to a method and system for generating a virtual road map of a predictive redirection controller. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Virtual reality (VR) applications based on head-mounted displays (HMDs) can provide users with a highly immersive interactive experience. In such systems, enabling users to move naturally within the virtual environment (locomotion), similar to walking in a physical environment, is crucial to enhancing immersion. Currently, the most straightforward approach is to create a 1:1 mapping between the virtual space and the physical space. However, this approach limits the user's mobility within the virtual environment to the dimensions of the physical environment.

[0004] To overcome this challenge, redirected walking (RDW) technology has emerged. This technology introduces deviations between virtual and physical walking trajectories, allowing users to explore a wider virtual world within a limited physical space. Redirection gain is the most fundamental and widely used RDW technique. This method modifies the user's walking trajectory by adding deviations in various dimensions, such as walking distance, rotation angle, and path curvature, while keeping these deviations imperceptible to the user.

[0005] In practical applications, to cope with more complex scenarios, a redirection controller is often used to combine different redirection gain strategies. Among these, the predicted redirection controller, one of the most effective controller methods, selects the most appropriate action from a predefined set of actions (i.e., redirection gain) and dynamically calculates the optimal position the user should be heading towards using a series of predefined virtual roadmaps. In this way, the controller can make appropriate adjustments based on complex environments, allowing users to immerse themselves in larger and more complex virtual scenes even within a limited physical space.

[0006] However, existing predictive redirection controllers suffer from two significant issues: First, they have poor scenario adaptability. Most are only suitable for simple corridor-like scenarios with straight boundaries and struggle to adapt to complex virtual environments with curved boundaries. Second, virtual road maps rely on manual annotation. Existing systems often require developers to manually design and annotate virtual road maps, resulting in low efficiency, lack of flexibility, and lack of automation capabilities. Summary of the Invention

[0007] In order to solve the above problems, the present invention proposes a method and system for generating a virtual road map of a predictive redirection controller. The present invention can support a virtual road map generation scheme of a predictive redirection controller for scenes with complex curved boundaries, thereby increasing the applicability of the predictive redirection controller and further enhancing the user immersion experience and system adaptability in the VR system.

[0008] According to some embodiments, the present invention adopts the following technical solutions: A method for generating a virtual road map of a predictive redirection controller comprises the following steps: Perform curve polygon subdivision on a given virtual scene and use the shortest path tree algorithm to calculate the shortest path tree of the user's current position in the scene; Perform skeleton processing on a given virtual scene to obtain a polygonal skeleton; Based on the shortest path tree, calculate the visible polygon area of the user's current location; Extract virtual waypoints based on the intersection of the visible polygon area and the polygon skeleton; Using clothoid curves to fit the paths between adjacent virtual waypoints; Determine whether the current waypoint depth meets the given depth. If not, repeat the steps of calculating the visible polygon area to fit the path with the next virtual waypoint as the user's current position until a virtual road map meeting the given depth is generated.

[0009] As an optional implementation, the process of performing curve polygonal subdivision on a given virtual scene includes: Calculate the Voronoi diagram of a given virtual scene; For each Voronoi vertex in the Voronoi diagram, obtain its vertical points on the three associated sites and connect them two by two to obtain a set of sub-polygons.

[0010] As an optional implementation, the process of calculating the shortest path tree of the user's current position in the scene using the shortest path tree algorithm includes: obtaining a sub-polygon containing the user's current position in the subdivided sub-polygon set; Add the sub-polygon to the queue, and if the queue is not empty, repeat the next step; Push the first sub-polygon out of the queue, calculate the shortest path tree from all vertices in the sub-polygon to the user's current location through the funnel data structure, and add the unprocessed neighbor sub-polygons of the sub-polygon to the queue; Get the shortest path tree with the user's current location as the root node.

[0011] As an optional implementation, the visible polygon area of the user's current location is calculated based on the shortest path tree, including: For each edge in the virtual scene, calculate the visible area of this edge for the user's current position; Connect the visible areas of each edge in sequence to obtain the visible polygon of the user's current location.

[0012] As a further limitation, for each edge in the virtual scene, calculating the visible area of the edge for the user's current position includes: Find the shortest paths from the user's current location to the two vertices of the edge from the shortest path tree; Starting from the user's current location, send out rays from the tangent direction of the starting position of the first segment of the two shortest paths to determine the intersection point with the edge; If there are two intersection points, the line segment connecting the two intersection points is the visible area of the edge; otherwise, the edge is invisible to the user's current location.

[0013] As an optional implementation, skeleton processing is performed on a given virtual scene to obtain a polygon skeleton, including the following steps: for an input curved polygon virtual scene, the Voronoi diagram of the curved polygon is calculated; based on the Voronoi diagram, for each Voronoi edge, if one of its endpoints is a vertex of the polygon, the Voronoi edge is deleted; otherwise, the Voronoi edge is retained to obtain a skeleton diagram of the curved polygon.

[0014] As an optional implementation, the specific process of using a clothoid curve to fit the path between adjacent virtual waypoints includes: Get the position of the first virtual waypoint as the starting position, and take the tangent direction of the virtual waypoint on the skeleton graph as the starting direction; Get the position of the second virtual waypoint as the end position, and the tangent direction of the waypoint on the skeleton graph as the end direction; A virtual path is fitted by a spiral curve fitting method using the starting position, starting direction, ending position and ending direction. The starting point and end point of the path are the starting position and the ending position respectively, and the tangent directions of the starting point and the end point of the path are the starting direction and the ending direction respectively.

[0015] A virtual road map generation system for a predictive redirection controller, comprising: A scene segmentation module is configured to perform curve polygon segmentation on a given virtual scene and calculate a shortest path tree of a user's current position in the scene using a shortest path tree algorithm; A scene skeleton processing module is configured to perform skeleton processing on a given virtual scene to obtain a polygonal skeleton; The visibility module is configured to calculate a visible polygon area of the user's current location based on a shortest path tree; a waypoint generation module configured to extract virtual waypoints based on intersections between visible polygonal areas and polygonal skeletons; a path fitting module configured to fit a path between adjacent virtual waypoints using a clothoid curve; The virtual road map generation module is configured to determine whether the current waypoint depth meets the given depth. If not, the visibility module, the waypoint generation module, and the path fitting module are repeatedly called with the next virtual waypoint as the user's current location until a virtual road map meeting the given depth is generated.

[0016] A computer-readable storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor of a terminal device and executing the steps in the method.

[0017] A terminal device includes a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the steps in the described method.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can process complex curve boundaries through a curve polygon decomposition algorithm based on the Voronoi diagram and a curve polygon skeleton extraction method, thereby improving the applicability of the predictive redirection controller to complex scenes containing curve boundaries.

[0019] 2. The solution described in the present invention automatically generates a virtual path that is more in line with human walking habits based on the virtual scene through a visible polygon-based waypoint generation mechanism and a circular curve-based path fitting, allowing developers to quickly develop a predictive redirection controller in any virtual scene.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 A schematic diagram of a virtual road map generation process in an embodiment; Figure 2 A schematic diagram of a virtual scene input in one embodiment; Figure 3 A schematic diagram of a Voronoi diagram of a virtual scene in an embodiment; Figure 4 A schematic diagram of a skeleton of a virtual scene based on a Voronoi diagram in an embodiment; Figure 5 A schematic diagram of a Voronoi diagram-based partitioning of a virtual scene in an embodiment; Figure 6 A schematic diagram of visible polygons in a virtual scene in one embodiment; Figure 7 A schematic diagram of virtual waypoints and virtual paths in a virtual scene in an embodiment. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0025] It should be noted that the terms used herein are for describing particular embodiments only and are not intended to limit the exemplary embodiments according to the present invention.

[0026] Example 1 A method for generating a virtual road map for a predictive redirection controller, such as Figure 1 As shown, the following steps are included: Step 1: Perform curve polygon division on the given virtual scene and use the shortest path tree algorithm to calculate the shortest path tree of the user's current position in the scene; Step 2: Perform skeleton processing on the given virtual scene to obtain a polygonal skeleton; Step 3: Based on the shortest path tree, calculate the visible polygon area of the user's current location; Step 4: Extract virtual waypoints based on the intersection of the visible polygon area and the polygon skeleton; Step 5: Use the clothoid curve to fit the path between adjacent virtual waypoints; Step 6: Determine whether the current waypoint depth meets the given depth. If not, take the next virtual waypoint as the user's current location and go to step 3. If yes, output the virtual road map, such as Figure 7 .

[0027] The process of performing curve polygonal subdivision on a given virtual scene includes: Step (1.1): For the input curve polygon virtual scene, go to step (1.2); Step (1.2): Calculate the Voronoi diagram of the curve polygon, such as Figure 2 As shown, go to step (1.3); Step (1.3): Calculate the sub-polygon set of the curve polygon based on the Voronoi diagram.

[0028] Among them, in the step (1.3), the specific steps include: Step (1.3.1): For each Voronoi vertex, execute step (1.3.2); after all are executed, go to step (1.3.4); Step (1.3.2): Calculate the vertical points on the three sites associated with the Voronoi vertex and go to step (1.3.3); Step (1.3.3): Connect the three vertical points in pairs to form a diagonal line, and go to step (1.3.1); Step (1.3.4): All diagonals divide the curve polygon into a set of sub-polygons.

[0029] In this embodiment, the steps of scene skeleton processing include: Step (2.1): For the input curve polygon virtual scene, calculate the Voronoi diagram of the curve polygon; Step (2.2): Calculate the skeleton diagram of the curve polygon based on the Voronoi diagram. Specifically, for each Voronoi edge, if there is an endpoint that is a vertex of the polygon, delete the Voronoi edge; otherwise, keep the Voronoi edge, such as Figure 4 shown.

[0030] In this embodiment, the process of calculating the visible polygon area of the user's current location based on the shortest path tree includes: Step (3.1): For the virtual scene represented by the input curve polygon, combine the segmentation results of the curve polygon, such as Figure 5 As shown, and the user's virtual position, go to step (3.2) to calculate; Step (3.2): Calculate the shortest path tree of the user's virtual position in the curve polygon, and go to step (3.3); Step (3.3): Based on the shortest path tree, calculate the visible polygon of the user's virtual position in the curve polygon, such as Figure 6 shown.

[0031] The step (3.2) specifically includes: Step (3.2.1): Get the sub-polygon containing the user's current position in the sub-polygon set, and go to step (3.2.2); Step (3.2.2): Add the sub-polygon to the queue. If the queue is not empty, repeat step (3.2.3). Otherwise, go to step (3.2.4). Step (3.2.3) pushes the first sub-polygon out of the queue, calculates the shortest path tree from all vertices in the sub-polygon to the user's current location using the funnel data structure, then adds the unprocessed neighbor sub-polygons of the sub-polygon to the queue and goes to step (3.2.2); Step (3.2.4): Get the shortest path tree with the user's current location as the root node.

[0032] Wherein, the step (3.3) specifically includes: Step (3.3.1): For each edge in the virtual scene, calculate the visible area of this edge for the user's current position, and go to step (3.3.2); Step (3.3.2): Connect the visible areas of each edge in sequence to obtain the visible polygon of the user's current position, such as Figure 6 shown.

[0033] The step (3.3.1) specifically includes: Step (3.3.1.1): Find the shortest paths from the user's current location to the two vertices of the edge in the shortest path tree, and go to step (3.3.1.2); Step (3.3.1.2): Starting from the user's current location, send a ray in the tangent direction of the starting position of the first segment of the two shortest paths and find the intersection point with the edge, then go to step (3.3.1.3); Step (3.3.1.3): If there are two intersection points, the line segment connecting the two intersection points is the visible area of the edge; otherwise, the edge is invisible to the user's current location.

[0034] The process of extracting virtual waypoints based on the intersection of the visible polygon area and the polygon skeleton includes: Step (4.1): For each edge e1 of the visible polygon and each edge e2 of the polygon skeleton, if e1 and e2 have an intersection, add them to the set R.

[0035] Step (4.2): Output R as a virtual waypoint.

[0036] The process of fitting the path between adjacent virtual waypoints using the clothoid curve includes: Step (5.1): Get the position of the first virtual waypoint as the starting position, and take the tangent direction of the virtual waypoint on the skeleton graph as the starting direction.

[0037] Step (5.2): Get the position of the second virtual waypoint as the end position, and the tangent direction of the waypoint on the skeleton graph is the end direction.

[0038] Step (5.3): A virtual path is fitted using a spiral curve fitting method using the starting position, starting direction, ending position, and ending direction. The starting point and ending point of the path are the starting position and ending position, respectively. The tangent directions of the starting point and ending point of the path are the starting direction and ending direction, respectively.

[0039] Example 2 A virtual road map generation system for a predictive redirection controller, comprising: A scene segmentation module is configured to perform curve polygon segmentation on a given virtual scene and calculate a shortest path tree of a user's current position in the scene using a shortest path tree algorithm; A scene skeleton processing module is configured to perform skeleton processing on a given virtual scene to obtain a polygonal skeleton; The visibility module is configured to calculate a visible polygon area of the user's current location based on a shortest path tree; a waypoint generation module configured to extract virtual waypoints based on intersections between visible polygonal areas and polygonal skeletons; a path fitting module configured to fit a path between adjacent virtual waypoints using a clothoid curve; The virtual road map generation module is configured to determine whether the current waypoint depth meets the given depth. If not, the visibility module, the waypoint generation module, and the path fitting module are repeatedly called with the next virtual waypoint as the user's current location until a virtual road map meeting the given depth is generated.

[0040] The execution steps of the specific modules have been described in detail in Example 1, so they will not be repeated here.

[0041] Example 3 This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of generating a virtual road map of a predictive redirection controller as described in the first embodiment are implemented.

[0042] Example 4 This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of generating a virtual road map of a predictive redirection controller as described in the first embodiment are implemented.

[0043] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0044] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0045] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0046] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0047] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0048] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A method for generating a virtual road map of a predictive redirection controller, characterized in that: The following steps are involved: Perform curve polygon subdivision on a given virtual scene and use the shortest path tree algorithm to calculate the shortest path tree of the user's current position in the scene; Perform skeleton processing on a given virtual scene to obtain a polygonal skeleton; Based on the shortest path tree, calculate the visible polygon area of the user's current location; Extract virtual waypoints based on the intersection of the visible polygon area and the polygon skeleton; Using clothoid curves to fit the paths between adjacent virtual waypoints; Determine whether the current waypoint depth meets the given depth. If not, repeat the steps of calculating the visible polygon area to fit the path with the next virtual waypoint as the user's current position until a virtual road map meeting the given depth is generated.

2. The method for generating a virtual road map of a predictive redirection controller according to claim 1, wherein: The process of curve polygonal meshing of a given virtual scene includes: Calculate the Voronoi diagram of a given virtual scene; For each Voronoi vertex in the Voronoi diagram, obtain its vertical points on the three associated sites and connect them two by two to obtain a set of sub-polygons.

3. The method for generating a virtual road map of a predictive redirection controller according to claim 1, wherein: The process of calculating the shortest path tree of the current position of the user in the scene using the shortest path tree algorithm includes: obtaining a sub-polygon containing the current position of the user in the subdivided sub-polygon set; Add the sub-polygon to the queue, and if the queue is not empty, repeat the next step; Push the first sub-polygon out of the queue, calculate the shortest path tree from all vertices in the sub-polygon to the user's current location through the funnel data structure, and add the unprocessed neighbor sub-polygons of the sub-polygon to the queue; Get the shortest path tree with the user's current location as the root node.

4. The method for generating a virtual road map of a predictive redirection controller according to claim 1, wherein: Based on the shortest path tree, calculate the visible polygon area of the user's current location, including: For each edge in the virtual scene, calculate the visible area of this edge for the user's current position; Connect the visible areas of each edge in sequence to obtain the visible polygon of the user's current location.

5. The method for generating a virtual road map of a predictive redirection controller according to claim 4, wherein: The step of calculating, for each edge in the virtual scene, the visible area of the edge relative to the user's current position includes: Find the shortest paths from the user's current location to the two vertices of the edge from the shortest path tree; Starting from the user's current location, send out rays from the tangent direction of the starting position of the first segment of the two shortest paths to determine the intersection point with the edge; If there are two intersection points, the line segment connecting the two intersection points is the visible area of the edge; otherwise, the edge is invisible to the user's current location.

6. The method for generating a virtual road map of a predictive redirection controller according to claim 1, wherein: The process of skeletonizing a given virtual scene to obtain a polygon skeleton includes: for the input curved polygon virtual scene, calculating the Voronoi diagram of the curved polygon; based on the Voronoi diagram, for each Voronoi edge, if one of its endpoints is a vertex of the polygon, then deleting the Voronoi edge; otherwise, retaining the Voronoi edge to obtain the skeleton diagram of the curved polygon.

7. The method for generating a virtual road map of a predictive redirection controller according to claim 1, wherein: The specific process of fitting the path between adjacent virtual waypoints using the clothoid curve includes: obtaining the position of the first virtual waypoint as the starting position, and taking the tangent direction of the virtual waypoint on the skeleton graph as the starting direction; Get the position of the second virtual waypoint as the end position, and the tangent direction of the waypoint on the skeleton graph as the end direction; A virtual path is fitted by a spiral curve fitting method using the starting position, starting direction, ending position and ending direction. The starting point and end point of the path are the starting position and the ending position respectively, and the tangent directions of the starting point and the end point of the path are the starting direction and the ending direction respectively.

8. A virtual road map generation system for a predictive redirection controller, characterized in that: include: A scene segmentation module is configured to perform curve polygon segmentation on a given virtual scene and calculate a shortest path tree of a user's current position in the scene using a shortest path tree algorithm; A scene skeleton processing module is configured to perform skeleton processing on a given virtual scene to obtain a polygonal skeleton; The visibility module is configured to calculate a visible polygon area of the user's current location based on a shortest path tree; a waypoint generation module configured to extract virtual waypoints based on intersections between visible polygonal areas and polygonal skeletons; a path fitting module configured to fit a path between adjacent virtual waypoints using a clothoid curve; The virtual road map generation module is configured to determine whether the current waypoint depth meets the given depth. If not, the visibility module, the waypoint generation module, and the path fitting module are repeatedly called with the next virtual waypoint as the user's current location until a virtual road map meeting the given depth is generated.

9. A computer-readable storage medium, characterized in that: A plurality of instructions are stored therein, and the instructions are suitable for being loaded by a processor of a terminal device and executing the steps of any one of the methods of claims 1-7.

10. A terminal device, characterized in that: The method comprises a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; and the computer-readable storage medium is used to store a plurality of instructions, wherein the instructions are suitable for being loaded by the processor and executing the steps in the method according to any one of claims 1 to 7.

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