Boundary layer grid push type generation method and system

Abstract

The embodiment of the invention provides a boundary layer grid push type generation method and system. The method comprises the following steps: segmenting a target axis alignment bounding box corresponding to a target model to generate a target sub-axis symmetric bounding box; updating the target sub-axisymmetric bounding box to generate a target cross judgment result; and executing a target boundary layer grid propulsion operation according to a target cross judgment result. In this way, the generation precision and the generation efficiency of the boundary layer grid can be improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of grid processing technology, and in particular to a boundary layer grid push-type generation method and system. Background Art

[0002] Boundary layer mesh generation is mainly used in industries such as aerospace, automotive, and energy to simulate turbulence and capture wall flow details, including flow separation and vortices.

[0003] In the related art, boundary layer grids have problems such as poor generation accuracy and low efficiency. Summary of the invention

[0004] According to an embodiment of the present application, a method and system for advancing generation of a boundary layer mesh are provided, which can improve the generation accuracy and generation efficiency of the boundary layer mesh.

[0005] In a first aspect of the present application, a boundary layer mesh advancing generation method is provided, comprising: Segment the target axis-aligned bounding box corresponding to the target model to generate a target sub-axis-symmetric bounding box; Update the target sub-axis symmetric bounding box to generate the target intersection judgment result; According to the target intersection judgment result, the target boundary layer grid advancement operation is performed; Updating the target sub-axis symmetric bounding box to generate the target intersection judgment result includes: Determine a target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle; According to the target axisymmetric bounding box, update the target sub-axisymmetric bounding box; Add the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box; Add the target attribute triangle to the target sub-axis symmetric bounding box; Generate target intersection judgment results based on the updated target sub-axis symmetric bounding box; The target mesh includes: a triangular prism mesh, a pyramid mesh, and / or a tetrahedron mesh.

[0006] In some feasible implementations, the target axis-aligned bounding box corresponding to the segmented target model is generated to generate a target sub-axisymmetric bounding box, including: performing a target segmentation operation on the target side of the target axis-aligned bounding box to generate a target sub-axis-symmetric bounding box; Among them, the length of the target edge is greater than the lengths of other edges; The number of target triangles in the target sub-axisymmetric bounding box is less than or equal to a preset number.

[0007] In some feasible implementations, the target attribute triangles include: non-propellable triangles, and / or non-wall triangles.

[0008] In some feasible implementations, generating the target intersection judgment result according to the updated target sub-axisymmetric bounding box includes: In the case where there is an intersection between target meshes, between target attribute triangles, and / or between a target mesh and a target attribute triangle, determining that a target intersection judgment result is that there is a target intersection; In the case where there is no intersection between target meshes, between target attribute triangles, and / or between a target mesh and a target attribute triangle, it is determined that the target intersection determination result is that there is no target intersection.

[0009] In some feasible implementations, the above-mentioned performing the target boundary layer grid advancement operation according to the target intersection judgment result includes: When it is determined that the target intersection judgment result is that there is no target intersection, a target mesh adding operation is performed according to the number of advanceable target points of the target triangle.

[0010] In some feasible implementations, the above method further includes: When it is determined that all neighboring target points of the propulsable target point can be propulsed, a target smoothing operation is performed on the propulsable target point, wherein the propulsable target point belongs to a target line segment and / or a target surface.

[0011] In a second aspect of the present application, a boundary layer grid push-type generation system is provided, comprising: A segmentation unit, used for segmenting a target axis-aligned bounding box corresponding to the target model to generate a target sub-axis-symmetric bounding box; An updating unit, used for updating the target sub-axis symmetric bounding box to generate a target intersection judgment result; An execution unit, used for executing a target boundary layer grid advancement operation according to a target intersection judgment result; Updating the target sub-axis symmetric bounding box to generate the target intersection judgment result includes: Determine a target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle; According to the target axisymmetric bounding box, update the target sub-axisymmetric bounding box; Add the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box; Add the target attribute triangle to the target sub-axis symmetric bounding box; Generate target intersection judgment results based on the updated target sub-axis symmetric bounding box; The target mesh includes: a triangular prism mesh, a pyramid mesh, and / or a tetrahedron mesh.

[0012] In a third aspect of the present application, an electronic device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the method described above when executing the computer program.

[0013] In a fourth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the method as described above is implemented.

[0014] The embodiment of the present application provides a boundary layer mesh push-up generation method and system, wherein the method includes: segmenting the target axis-aligned bounding box corresponding to the target model to generate a target sub-axisymmetric bounding box; updating the target sub-axisymmetric bounding box to generate a target intersection judgment result; and performing a target boundary layer mesh push-up operation according to the target intersection judgment result. The present application can improve the generation accuracy and generation efficiency of the boundary layer mesh.

[0015] It should be understood that the contents described in the Summary of the Invention are not intended to limit the key or important features of the embodiments of the present application, nor are they intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other features, advantages and aspects of the embodiments of the present application will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein: Figure 1 A schematic diagram of a process of a boundary layer mesh push-type generation method provided according to an embodiment of the present application; Figure 2 A schematic structural diagram of a boundary layer grid propulsion generation system provided according to an embodiment of the present application; Figure 3 It is a schematic diagram of the structure of an electronic device suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0018] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0019] In a first aspect of the present application, a boundary layer mesh advancing generation method is provided. Figure 1 A schematic diagram of a process of generating a boundary layer mesh by pushing forward method 100 provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the method 100 includes: In some feasible implementations, the following step S1 may be performed when the layer sequence number of the target boundary layer of the current target model meets the preset scenario. The preset scenario may be set according to actual needs.

[0020] Exemplarily, when the layer sequence number of the target boundary layer of the current target model is 1, the following step S1 may be performed.

[0021] Step S1: Segment the target axis-aligned bounding box corresponding to the target model to generate a target sub-axisymmetric bounding box.

[0022] For example, the target axis-aligned bounding box can be based on the vertices of all surface triangles of the target model. Axis coordinates, Axis coordinates and The maximum and minimum values ​​of the axis coordinates are determined. The target axis-aligned bounding box contains the The maximum and minimum values ​​of the axis coordinates, The maximum and minimum values ​​of the axis coordinates and The maximum and minimum values ​​of the axis coordinates.

[0023] In some feasible implementations, the above step S1: segmenting the target axis-aligned bounding box corresponding to the target model to generate a target sub-axisymmetric bounding box includes: Step S11: perform a target segmentation operation on the target edge of the target axis-aligned bounding box to generate a target sub-axisymmetric bounding box; wherein the length of the target edge is greater than the lengths of other edges; and the number of target triangles in the target sub-axisymmetric bounding box is less than or equal to a preset number.

[0024] For example, based on the bisection method, the target segmentation operation can be performed on the longest side of the target axis-aligned bounding box, so that the number of target triangles in the target sub-axisymmetric bounding box is less than or equal to a preset number. The target triangles can include: wall triangles in the target sub-axisymmetric bounding box.

[0025] Therefore, the above method can realize automatic and accurate target segmentation operation on the target axis-aligned bounding box corresponding to the target model, improve the generation accuracy and efficiency of the target axis-aligned bounding box and the target triangle, and thus improve the efficiency of intersection judgment.

[0026] Step S2: Update the target sub-axis symmetric bounding box to generate a target intersection judgment result.

[0027] In some feasible implementations, the above step S2: updating the target sub-axisymmetric bounding box to generate a target intersection judgment result includes: Step S21: Determine a target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle.

[0028] It should be noted that the target mesh axisymmetric bounding box corresponding to the target triangle may include: a triangular prism mesh axisymmetric bounding box, a pyramid mesh axisymmetric bounding box, and / or a tetrahedron mesh axisymmetric bounding box corresponding to the target triangle.

[0029] Exemplarily, the target axisymmetric bounding box can be calculated and determined based on the above-mentioned triangular prism grid axisymmetric bounding box, pyramid grid axisymmetric bounding box, and / or tetrahedron grid axisymmetric bounding box. Wherein, the above-mentioned target axisymmetric bounding box can correspond to the maximum axisymmetric bounding box corresponding to the above-mentioned triangular prism grid axisymmetric bounding box, pyramid grid axisymmetric bounding box, and / or tetrahedron grid axisymmetric bounding box.

[0030] For example: the maximum and minimum values ​​of the coordinates of the six vertices of the axisymmetric bounding box of the triangular prism grid, the maximum and minimum values ​​of the five vertices of the axisymmetric bounding box of the pyramid grid, and / or the maximum and minimum values ​​of the four vertices of the axisymmetric bounding box of the tetrahedron grid can be calculated, and the above-mentioned maximum axisymmetric bounding box can be determined based on the maximum and minimum values ​​of the coordinates of the six vertices of the axisymmetric bounding box of the triangular prism grid, the maximum and minimum values ​​of the five vertices of the axisymmetric bounding box of the pyramid grid, and / or the maximum and minimum values ​​of the four vertices of the axisymmetric bounding box of the tetrahedron grid.

[0031] Step S22: According to the target axisymmetric bounding box, update the target sub-axisymmetric bounding box.

[0032] Exemplarily, the size of the target sub-axisymmetric bounding box may be updated according to the size of the maximum axisymmetric bounding box.

[0033] Specifically, the coordinate values ​​corresponding to the axes of the target sub-axisymmetric bounding box can be updated based on the difference between the minimum value of the coordinates of the axes of the target sub-axisymmetric bounding box and the maximum value of the coordinates of the axes of the bounding box, and the sum of the maximum value of the coordinates of the axes of the bounding box and the maximum value of the coordinates of the axes of the bounding box.

[0034] Step S23: Add the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box.

[0035] In some feasible implementations, the target grid includes: a triangular prism grid, a pyramid grid, and / or a tetrahedron grid.

[0036] Exemplarily, the center coordinates of the triangular prism mesh, pyramid mesh, and / or tetrahedral mesh corresponding to all target triangles can be updated according to the size, i.e., coordinates, of the target sub-axisymmetric bounding box, and the triangular prism mesh, pyramid mesh, and / or tetrahedral mesh can be added to the target sub-axisymmetric bounding box according to the updated center coordinates of the triangular prism mesh, pyramid mesh, and / or tetrahedral mesh.

[0037] Alternatively, the target sub-axisymmetric bounding box may be updated based on the average value of the coordinates of six vertices of the triangular prism mesh, the average value of the coordinates of five vertices of the pyramid mesh, and / or the average value of the coordinates of four vertices of the tetrahedron mesh.

[0038] Therefore, the above method helps to further improve the generation accuracy and efficiency of the target sub-axisymmetric bounding box by adding triangular prism grids, pyramid grids, and / or tetrahedral grids to the target sub-axisymmetric bounding box, thereby improving the generation accuracy and efficiency of the target intersection judgment result, and further improving the generation accuracy and efficiency of the boundary layer grid.

[0039] Step S24: Add the target attribute triangle to the target sub-axisymmetric bounding box.

[0040] In some feasible implementations, the target attribute triangle includes: a non-propellable triangle, and / or a non-wall triangle.

[0041] Exemplarily, the non-propellable triangles and / or non-wall triangles mentioned above may be added to the target sub-axisymmetric bounding box.

[0042] Therefore, the above method further improves the generation accuracy and efficiency of the target sub-axisymmetric bounding box by adding non-propellable triangles and / or non-wall triangles to the target sub-axisymmetric bounding box, thereby further improving the generation accuracy and efficiency of the target intersection judgment result, and further improving the generation accuracy and efficiency of the boundary layer mesh.

[0043] Step S25: Generate a target intersection judgment result based on the updated target sub-axisymmetric bounding box.

[0044] Exemplarily, the target intersection judgment result may be generated based on the intersection of the triangular prism grid, pyramid grid, tetrahedron grid, the non-propellable triangle, and / or the non-wall triangle in each target sub-axisymmetric bounding box.

[0045] In some feasible implementations, the above step S25: generating a target intersection determination result according to the updated target sub-axisymmetric bounding box includes: Step S251: When there is an intersection between target meshes, between target attribute triangles, and / or between a target mesh and a target attribute triangle, determining that a target intersection judgment result is that there is a target intersection.

[0046] Exemplarily, when there is an intersection between the above-mentioned triangular prism grid, pyramid grid, tetrahedron grid, the above-mentioned unpropellable triangle, and / or the above-mentioned non-wall triangle, the target intersection judgment result is determined to be that there is a target intersection.

[0047] It should be noted that, when the target intersection judgment result is determined to be a target intersection, the target triangle corresponding to the pushable target point can be set to 0. The above-mentioned pushable target point corresponds to the pushable vertex of the above-mentioned target triangle. That is, when the target intersection judgment result is determined to be a target intersection, the three vertices corresponding to the target triangle can be set to non-pullable target points.

[0048] Step S252: When there is no intersection between target meshes, between target attribute triangles, and / or between a target mesh and a target attribute triangle, determine that the target intersection judgment result is that there is no target intersection.

[0049] Exemplarily, when there is no intersection between the above-mentioned triangular prism grid, pyramid grid, tetrahedron grid, the above-mentioned non-propellable triangle, and / or non-wall triangle, the target intersection judgment result is determined to be that there is no target intersection.

[0050] It should be noted that the above-mentioned intersection judgment between meshes and between meshes and faces can be transformed into intersection judgment between triangles and line segments, which can be specifically implemented based on a preset computer graphics algorithm.

[0051] For example, taking the determination of whether there is an intersection between a triangular prism mesh and a tetrahedral mesh as an example, considering the warping of the side quadrilaterals of the triangular prism mesh, the triangular prism mesh can be decomposed into 2 bottom triangles and 6 side triangles, where the tetrahedral mesh has 6 edges, and it can be determined in turn whether each edge of the tetrahedral mesh intersects with the 8 triangles of the triangular prism mesh. If there is an intersection, it is determined that there is an intersection between the triangular prism mesh and the tetrahedral mesh, and the target intersection determination result is that there is a target intersection; if all edges of the tetrahedral mesh and all faces of the triangular prism mesh do not intersect, it is determined that there is no intersection between the triangular prism mesh and the tetrahedral mesh, and the target intersection determination result is that there is no target intersection.

[0052] Therefore, the above method can realize multi-dimensional and all-round accurate generation of target intersection judgment results according to the intersection between target grids, between target attribute triangles, and / or between target grids and target attribute triangles, which is conducive to improving the generation accuracy and efficiency of target intersection judgment results, thereby improving the execution accuracy and efficiency of target boundary layer grid advancement operations.

[0053] Based on this, the above method can realize automatic and accurate determination of the target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle; accurate and automatic update of the target sub-axisymmetric bounding box according to the target axisymmetric bounding box; automatic and accurate addition of the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box; automatic and accurate addition of the target attribute triangle to the target sub-axisymmetric bounding box; automatic and accurate generation of the target intersection judgment result according to the updated target sub-axisymmetric bounding box, thereby improving the generation accuracy and generation efficiency of the target intersection judgment result, reducing the time consumption of intersection judgment in the process of boundary layer mesh advancement generation, and thus improving the execution accuracy and execution efficiency of the target boundary layer mesh advancement operation.

[0054] Step S3: Execute the target boundary layer grid advancement operation according to the target intersection judgment result.

[0055] Exemplarily, a target grid adding operation may be performed according to the target intersection determination result to complete the target boundary layer grid advancing operation.

[0056] In some feasible implementations, the above step S3: performing the target boundary layer grid advancement operation according to the target intersection judgment result includes: Step S31: When it is determined that the target intersection judgment result is that there is no target intersection, a target mesh adding operation is performed according to the number of target points that can be advanced in the target triangle.

[0057] Exemplarily, when there is no intersection between the above-mentioned triangular prism mesh, pyramid mesh, tetrahedron mesh, the above-mentioned non-propellable triangle, and / or non-wall triangle, the corresponding target mesh adding operation can be performed according to the number of propellable target points of the target triangle, wherein the above-mentioned propellable target points correspond to the propellable vertices of the above-mentioned target triangle.

[0058] Specifically, when the number of pushable vertices of the target triangle is 3, a triangular prism mesh addition operation may be performed. When the number of pushable vertices of the target triangle is 2, a pyramid mesh addition operation may be performed. When the number of pushable vertices of the target triangle is 1, a tetrahedron mesh addition operation may be performed.

[0059] Specifically, the corresponding data variables may be used to perform the corresponding target mesh adding operation, and the triangular prism mesh, the pyramid mesh, and / or the tetrahedron mesh may be added and stored in the data variables of the corresponding mesh type.

[0060] It should be noted that the three vertices corresponding to the target triangle of the added pyramid mesh and / or tetrahedral mesh may be set as non-propellable target points.

[0061] Therefore, the above method can achieve accurate execution of the target mesh adding operation according to the number of target points that can be advanced in the target triangle after completing the intersection judgment, so as to facilitate the tetrahedron segmentation in the process of boundary layer mesh advancement generation.

[0062] It should be noted that, when it is determined that the current number of boundary layers reaches the preset number of layers, that is, the current boundary layer number reaches the preset requirement, the above-mentioned target boundary layer grid advancement operation can be stopped; when it is determined that the current number of boundary layers does not reach the preset number of layers, that is, the current boundary layer number does not reach the preset requirement, the above-mentioned target boundary layer grid advancement operation can be continued.

[0063] In some feasible implementations, the above method further includes: before executing the above steps S1-S3, executing the following steps: Step Sa: Obtain target information, wherein the target information includes: triangle mesh information and target parameter information corresponding to the target model.

[0064] Exemplarily, the triangle mesh information corresponding to the target model may include: surface information, and / or type information, wherein the type information includes: wall triangles and non-wall triangles.

[0065] Exemplarily, the target parameter information may include: target boundary layer first layer thickness, target transition ratio and target number of layers.

[0066] It should be noted that the target boundary layer thickness can be determined based on the following formula according to the above target parameter information: (1)； in, For the Boundary layer thickness; is the first layer thickness of the target boundary layer; is the target transition ratio, is the target number of layers.

[0067] Step Sb: Determine the propulsability of the target point according to the target propulsion direction corresponding to the target point.

[0068] Exemplarily, the target propulsion direction corresponding to the target point may be determined according to the average value of the normal vectors of all adjacent triangles of the triangle target point.

[0069] It should be noted that, when the target point is a vertex or a point on an edge, the average advancement direction can be determined according to the normal vectors of any pair of adjacent triangles among all adjacent triangles corresponding to the target point.

[0070] Exemplarily, when the product of the above average advancing direction and the normal vectors of all adjacent triangles corresponding to the target point is greater than 0, the target point is determined to be a propellable point, and the angle corresponding to the average advancing direction is determined based on the following formula: (2)； in, is the angle corresponding to the average propulsion direction, is the vector corresponding to the average propulsion direction, The normal vector of the triangles adjacent to the target point.

[0071] It should be noted that, when traversing all adjacent triangle pairs and the minimum value of the angle corresponding to the above average propulsion direction is determined to be less than the current minimum value of the target angle, the above average propulsion direction is determined as the target propulsion direction, and the minimum value of the angle corresponding to the above average propulsion direction is determined as the target angle.

[0072] It should be noted that after completing the above operations, the target advancing direction and target angle can be determined again based on any three adjacent triangles among all adjacent triangles corresponding to the target point. The above determination process is similar to the above steps and will not be described in detail.

[0073] Exemplarily, if any dot product result of the above average advancing direction and the normal vectors of all adjacent triangles corresponding to the target point is less than or equal to 0, the target point is determined to be a non-advanced point.

[0074] Step Sc: When it is determined that all adjacent target points of the propulsable target point can be pushed, a target smoothing operation is performed on the propulsable target point, wherein the propulsable target point belongs to a target line segment and / or a target surface.

[0075] It should be noted that geometric data can be divided into geometric points, geometric lines and geometric surfaces. After performing the surface meshing operation, the geometric points are mesh points; the geometric lines are divided into polylines composed of several line segments; and the geometric surfaces are divided into discrete surfaces composed of triangles. Where the target point belongs to the target line segment, the target point may include: the internal points of the target line segment except the endpoints. Where the target point belongs to the target surface, the target point may include: the internal points of the target surface except the points on the boundary line.

[0076] It can be understood that the aforementioned adjacent target point may include: a point adjacent to the aforementioned propulsible target point.

[0077] Exemplarily, when it is determined that all adjacent target points corresponding to the target line segment and / or the target surface that can be pushed can be pushed, the target smoothing operation can be performed based on the following formula.

[0078] (3)； in, is the final target normal vector; is the target weight factor; is the initial target normal vector; is the number of adjacent target points; For the Normal vectors of adjacent target points.

[0079] It should be noted that the above final target normal vector Corresponding to the target point advancing direction. The above target weight factor For the initial target normal vector and the contribution between the average normal vector. Among them, the above target weight factor Greater than 0 and less than 1. Normal vectors of adjacent target points For the The advancing direction of adjacent target points.

[0080] Exemplarily, the target smoothing operation may be performed on the target points that can be propelled and belong to the target line segment first, and then the target smoothing operation may be performed on the target points that can be propelled and belong to the target surface.

[0081] Therefore, the above method can improve the determination accuracy and efficiency of the local point advancement direction through the smoothing strategy of local lines and surfaces, avoid the unreasonable advancement direction of local points, thereby improving the generation accuracy and efficiency of boundary layer meshes, and avoid the negative volume of boundary layer meshes, which leads to the failure of boundary layer mesh generation.

[0082] It should be noted that after the above step Sc, the current boundary layer thickness can be determined according to the layer sequence number of the current boundary layer based on the following formula, the coordinates of the propulsable target points can be determined according to the above current boundary layer thickness, and the propulsability of the above target triangle can be determined according to the number of propulsable target points.

[0083] (4)； in, The coordinates of the next layer corresponding to the current point; is the current point coordinate; is the current boundary layer thickness; A unit vector representing the direction in which the current point can be advanced.

[0084] Among them, the above distance Is a scalar that represents the distance from the reference point to the target point.

[0085] It should be noted that the current point can be determined as a propellable point or a non-propellable point based on the above coordinates. If the three vertices of the triangle are all non-propellable points, the triangle is determined to be a non-propellable triangle; if the three vertices of the triangle are all propellable points, the triangle is determined to be a propellable triangle.

[0086] Exemplarily, the quality of the triangular prism meshes corresponding to all the pushable triangles in the current layer may be determined based on the following formula. When it is determined that the quality of the triangular prism meshes corresponding to all the pushable triangles in the current layer is less than a preset threshold, the three vertices corresponding to the pushable triangles may be marked as non-pushing points: (5)； in, is the triangular prism mesh quality corresponding to all the pushable triangles in the current layer, For the triangular prism The local mesh quality corresponding to each vertex.

[0087] Among them, the triangular prism Local mesh quality corresponding to vertices Determined based on the following formula: (6)； in, is the target Jacobian matrix; is the target Jacobian matrix The corresponding first target column vector; is the target Jacobian matrix The corresponding second target column vector; is the target Jacobian matrix The corresponding third target column vector.

[0088] Among them, the target Jacobian matrix Determined based on the following formula: (7)； in, , , for Coordinates about , as well as Partial derivatives of coordinates, used to describe Coordinates follow , as well as The rate of change.

[0089] in, , , for Coordinates about , as well as Partial derivatives of coordinates, used to describe Coordinates follow , as well as The rate of change.

[0090] in, , , for Coordinates about , as well as Partial derivatives of coordinates, used to describe Coordinates follow , as well as The rate of change.

[0091] in, , and and , and The relationship is determined based on the following formula: (8)； (9)； (10)； Among them, , , is the coordinate of the target point in three-dimensional space, is the target standard function; The target prism vertex of Axis coordinates; The target prism vertex of Axis coordinates; The target prism vertex of Axis coordinates.

[0092] Among them, the target standard function , determined based on the following formula: (11)； (12)； (13)； (14)； (15)； (16)； in, is the target standard function corresponding to the vertex of the first target triangular prism; is the target standard function corresponding to the vertex of the second target triangular prism; is the target standard function corresponding to the vertex of the third target triangular prism; is the target standard function corresponding to the fourth target triangular prism vertex; is the target standard function corresponding to the fifth target triangular prism vertex; is the target standard function corresponding to the sixth target triangular prism vertex.

[0093] Based on this, the embodiments of the present application provide a boundary layer mesh pushing generation method and system, which can realize the automatic and precise segmentation of the target axis-aligned bounding box corresponding to the target model to accurately generate the target sub-axisymmetric bounding box; automatically update the target sub-axisymmetric bounding box to accurately generate the target intersection judgment result; according to the target intersection judgment result, automatically and accurately execute the target boundary layer mesh pushing operation to improve the generation accuracy and efficiency of the boundary layer mesh.

[0094] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0095] The above is an introduction to the method embodiment. The following is a further explanation of the solution described in this application through a system embodiment.

[0096] Figure 2 FIG. 2 shows a structural schematic diagram of a boundary layer grid push-type generation system 200 proposed in an embodiment of the present application, such as Figure 2 The system 200 shown includes a segmentation unit 210 , an update unit 220 , and an execution unit 230 .

[0097] A segmentation unit 210 is used to segment the target axis-aligned bounding box corresponding to the target model to generate a target sub-axisymmetric bounding box; An updating unit 220, used for updating the target sub-axis symmetric bounding box to generate a target intersection judgment result; An execution unit 230 is used to execute a target boundary layer grid advancement operation according to a target intersection judgment result; Updating the target sub-axis symmetric bounding box to generate the target intersection judgment result includes: Determine a target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle; According to the target axisymmetric bounding box, update the target sub-axisymmetric bounding box; Add the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box; Add the target attribute triangle to the target sub-axis symmetric bounding box; Generate target intersection judgment result according to the updated target sub-axis symmetric bounding box; The target mesh includes: a triangular prism mesh, a pyramid mesh, and / or a tetrahedron mesh.

[0098] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0099] In a third aspect of the present application, an electronic device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the method described above when executing the computer program.

[0100] Figure 3 A schematic diagram of the structure of an electronic device suitable for implementing the embodiments of the present application is shown.

[0101] like Figure 3 As shown, the electronic device includes a central processing unit (CPU) 301, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 302 or a program loaded from a storage part 308 into a random access memory (RAM) 303. In RAM 303, various programs and data required for the operation of the electronic device are also stored. CPU 301, ROM 302 and RAM 303 are connected to each other via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0102] The following components are connected to the I / O interface 305: an input section 306 including a keyboard, a mouse, etc.; an output section 307 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a LAN card, a modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 310 is also connected to the I / O interface 305 as needed. A removable medium 311, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 310 as needed, so that a computer program read therefrom is installed into the storage section 308 as needed.

[0103] In particular, according to an embodiment of the present application, the above method flow steps can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a machine-readable medium, and the computer program includes a program code for executing the method shown in the flow chart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 309, and / or installed from the removable medium 311. When the computer program is executed by the central processing unit (CPU) 301, the above-mentioned functions defined in the system of the present application are executed.

[0104] In a fourth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the method as described above is implemented.

[0105] It should be noted that the computer-readable medium shown in the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0106] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of the code, and the aforementioned module, program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0107] The units or modules involved in the embodiments described in the present application may be implemented by software or hardware. The units or modules described may also be arranged in a processor. The names of these units or modules do not, in some cases, constitute limitations on the units or modules themselves.

[0108] As another aspect, the present application further provides a computer-readable storage medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable storage medium stores one or more programs, and when the above programs are used by one or more processors to execute the method described in the present application.

[0109] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of application involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the aforementioned application concept. For example, the above features are replaced with (but not limited to) technical features with similar functions applied in the present application.

Claims

1. A boundary layer mesh advancing generation method, characterized in that: include: Segment the target axis-aligned bounding box corresponding to the target model to generate a target sub-axis-symmetric bounding box; Updating the target sub-axisymmetric bounding box to generate a target intersection judgment result; According to the target intersection judgment result, performing a target boundary layer grid advancement operation; The updating of the target sub-axisymmetric bounding box to generate a target intersection judgment result includes: Determine a target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle; According to the target axisymmetric bounding box, updating the target sub-axisymmetric bounding box; Add the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box; Adding a target attribute triangle to the target sub-axisymmetric bounding box; Generating the target intersection judgment result according to the updated target sub-axisymmetric bounding box; The target grid includes: a triangular prism grid, a pyramid grid, and / or a tetrahedron grid.

2. The boundary layer grid advancing generation method according to claim 1, characterized in that: The target axis-aligned bounding box corresponding to the segmented target model is generated to generate a target sub-axisymmetric bounding box, including: Performing a target segmentation operation on the target edge of the target axis-aligned bounding box to generate the target sub-axisymmetric bounding box; Wherein, the length of the target edge is greater than the lengths of other edges; The number of target triangles in the target sub-axisymmetric bounding box is less than or equal to a preset number.

3. The boundary layer grid advancing generation method according to claim 1, characterized in that: The target attribute triangles include: non-propellable triangles and / or non-wall triangles.

4. The boundary layer grid advancing generation method according to claim 3, characterized in that: Generating the target intersection judgment result according to the updated target sub-axisymmetric bounding box includes: In the case where there is an intersection between the target grids, between the target attribute triangles, and / or between the target grid and the target attribute triangles, determining that the target intersection judgment result is that there is a target intersection; In the case where there is no intersection between the target meshes, between the target attribute triangles, and / or between the target mesh and the target attribute triangles, it is determined that the target intersection judgment result is that there is no target intersection.

5. The boundary layer grid advancing generation method according to claim 4, characterized in that: The performing of the target boundary layer grid advancement operation according to the target intersection judgment result comprises: When it is determined that the target intersection judgment result is that there is no target intersection, the target mesh adding operation is performed according to the number of the target points that can be advanced of the target triangle.

6. The boundary layer grid pushing generation method according to any one of claims 1 to 5, characterized in that: Also includes: When it is determined that all adjacent target points of a propulsable target point can be propulsed, a target smoothing operation is performed on the propulsable target point, wherein the propulsable target point belongs to a target line segment and / or a target surface.

7. A boundary layer grid push generation system, characterized in that: include: A segmentation unit, used for segmenting a target axis-aligned bounding box corresponding to the target model to generate a target sub-axis-symmetric bounding box; An updating unit, used for updating the target sub-axisymmetric bounding box to generate a target intersection judgment result; An execution unit, configured to execute a target boundary layer grid advancement operation according to the target intersection judgment result; The updating of the target sub-axisymmetric bounding box to generate a target intersection judgment result includes: Determine a target axisymmetric bounding box according to the target mesh axisymmetric bounding box corresponding to the target triangle; According to the target axisymmetric bounding box, updating the target sub-axisymmetric bounding box; Add the target mesh corresponding to the target triangle to the target sub-axisymmetric bounding box; Adding a target attribute triangle to the target sub-axisymmetric bounding box; Generating the target intersection judgment result according to the updated target sub-axisymmetric bounding box; The target grid includes: a triangular prism grid, a pyramid grid, and / or a tetrahedron grid.

8. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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