Feature shell mesh fusion with backplane shell mesh, systems, devices, and media

Abstract

The application belongs to the technical field of automobile CAE simulation preprocessing. The application provides a feature shell mesh and back plate shell mesh fusion method, system, device and medium, comprising: dividing the back plate shell unit into multiple partitions, performing explicit penetration detection on the feature shell unit set and the back plate shell unit set, establishing intersection association, constructing a local plane of the feature shell unit and obtaining an effective back plate edge and an effective intersection point; identifying a cross-partition shared edge, adsorbing the end point node of the shared edge that is closer to the effective intersection point to the effective intersection point, and performing intersection connection according to the partition; deleting an error side and an approximately coincident residual shell unit based on a global reserved side and a local back plate reference plane, and re-identifying an implicit to-be-connected edge to implement compensation connection and re-cleaning, so as to obtain a fusion model with continuous topology. The application can improve the automatic connection success rate and stability of the complex back plate region, and reduce local mesh distortion and manual cleaning work.

Description

Technical Field

[0001] This application belongs to the field of automotive CAE simulation preprocessing technology, and particularly relates to a method, system, device and medium for fusing feature shell mesh and backplate shell mesh. Background Technology

[0002] In the automatic modeling process of computer-aided engineering (CAE) for automotive non-metallic parts, castings, and local structures, it is usually necessary to replace the pre-fabricated feature shell mesh onto the mid-surface mesh of the base backplate. After casting or region partitioning, the backplate is usually composed of multiple local mesh partitions, and different partitions may have different normals, curvatures, and bending directions.

[0003] When a feature shell element intersects with a backplate partition at its boundary, the intersection point may fall on a shared edge used by both backplate partitions. Directly performing a global intersection connection on the feature shell mesh and the entire backplate mesh can easily lead to the following problems: ① There are no real nodes corresponding to the geometric intersection points at the shared edges across partitions, resulting in intersection failure or no geometric change after intersection; ② A one-time overall intersection may affect unrelated backplate areas, causing local mesh distortion; ③ Explicit penetration detection is difficult to detect implicit unconnected edges such as boundary contact, small gaps, and unclosed local boundaries; ④ The newly generated shell elements after intersection may contain both effective connected elements and residual elements on the wrong side or elements that approximately coincide with the backplate; ⑤ Using fixed coordinate directions to delete residual elements is difficult to adapt to backplate models with arbitrary spatial orientation, different normals, and complex curved surfaces.

[0004] Existing processing methods typically rely on engineers to check each penetration location, move nodes, repeatedly perform intersections, and manually delete residual cells, resulting in long processing times and inconsistent results. Summary of the Invention

[0005] In view of this, this application aims to propose a method, system, device and medium for fusing feature shell meshes and back shell meshes, so as to solve the problems of low success rate of cross-partition connection, missed detection in explicit penetration detection and difficulty in automatically cleaning up intersecting residual cells in the existing connection process of feature shell meshes and back shell meshes.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: Firstly, this application provides a method for fusing feature shell meshes and backplate shell meshes, including: Obtain the set of feature shell units, the set of feature connecting edges, and the set of backplate shell units. Divide the set of backplate shell units into multiple non-overlapping backplate partitions and establish a mapping relationship between the backplate shell units and the partitions. By performing explicit penetration detection on the set of feature shell units and the set of backplate shell units and establishing intersection correlation, a set of intersecting feature shell units is obtained. A local plane is constructed for each feature shell unit in the set of intersecting feature shell units to determine the effective backplate edge and effective intersection point intersecting with the local plane. In response to the fact that the effective backplane edge is shared by two backplane shell units belonging to different backplane partitions, the effective backplane edge is determined as a cross-partition shared edge, and the endpoint of the two endpoints of the shared edge that is closest to the effective intersection point is attached to the effective intersection point; The pre-corrected feature shell elements are sequentially connected to each backplate partition for the first time, and the retained side and local backplate reference plane are determined based on the pre-marked backplate source shell element set. The feature source residual shell elements located on the deletion side or approximately overlapping with the backplate are deleted. Re-identify the feature connection edges that do not match the free boundary of the backplane, perform a second intersection connection on the feature shell units associated with the feature connection edges, and clean up the residual shell units generated by the connection again to obtain the fusion model of the continuous topology.

[0007] Secondly, based on the same inventive concept, this application also provides a system for fusing feature shell meshes and backplate shell meshes, including: The partitioning module is configured to acquire a set of feature shell units, a set of feature connecting edges, and a set of backplate shell units, divide the set of backplate shell units into multiple non-overlapping backplate partitions, and establish a mapping relationship between the backplate shell units and the partitions. The local plane construction module is configured to obtain a set of intersecting shell elements by performing explicit penetration detection on the set of feature shell elements and the set of backplate shell elements and establishing intersection associations, and to construct a local plane for each feature shell element in the set of intersecting shell elements to determine the effective backplate edges and effective intersection points that intersect with the local plane. An explicit connection module is configured to, in response to the effective backplane edge being shared by two backplane shell units belonging to different backplane partitions, identify the effective backplane edge as a cross-partition shared edge and snap the endpoint of the shared edge that is closest to the effective intersection point to the effective intersection point. The residual cleanup module is configured to sequentially perform the first intersection connection between the pre-corrected feature shell units and each backplane partition, and determine the retention side and local backplane reference plane based on the pre-marked backplane source shell unit set, and delete the feature source residual shell units located on the deletion side or approximately overlapping with the backplane. The compensation connection module is configured to re-identify feature connection edges that do not match the free boundary of the backplane, perform a second intersection connection on the feature shell units associated with the feature connection edges, and clean up the residual shell units generated by the connection again to obtain a fusion model of continuous topology.

[0008] Thirdly, based on the same inventive concept, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method described in the first aspect.

[0009] Fourthly, based on the same inventive concept, this application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions for causing the computer to perform the method as described in the first aspect.

[0010] Compared with the prior art, the method, system, device and medium for fusing feature shell mesh and backplate shell mesh described in this application have the following advantages: This application partitions the backplate shell mesh and identifies cross-partition shared edges during the intersection of the feature shell mesh and the backplate shell mesh. Real mesh nodes on the shared edges that are close to the effective intersection point are snapped to the intersection point, transforming the geometric intersection point into a real node that can directly participate in subsequent intersection connections. This improves the connection success rate at complex partition boundaries and reduces local mesh distortion caused by node adjustments. Furthermore, through partition intersection connections and the determination of residual shell elements based on the globally retained side and the local backplate reference plane, erroneous sides and approximately overlapping residual elements can be automatically removed. Compensation connections and secondary residual cleanup are then performed on implicit edges to be connected, forming a complete automatic processing closed loop. This improves the topological continuity, connection stability, and processing efficiency after the feature shell mesh and backplate shell mesh are merged, while reducing manual node movement, repeated connections, and manual cleanup work. Attached Figure Description

[0011] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart illustrating a method for fusing a feature shell mesh and a backplate shell mesh according to an embodiment of this application. Figure 2 This is a schematic diagram of the intersection of the feature shell unit set and the back plate edge as described in the embodiments of this application; Figure 3 This is a schematic diagram illustrating cross-partition shared edge identification as described in an embodiment of this application; Figure 4This is a schematic diagram of the nearest node of the cross-partition shared edge as described in the embodiments of this application; Figure 5 This is a schematic diagram of cross-partition shared edge node adsorption as described in an embodiment of this application; Figure 6 This is a schematic diagram illustrating the identification of invisible edges to be connected as described in an embodiment of this application; Figure 7 This is a schematic diagram of the invisible compensation connection described in an embodiment of this application; Figure 8 This is a schematic diagram illustrating the UP / DOWN classification of candidate residual shell units as described in an embodiment of this application; Figure 9 This is a schematic diagram of the ON classification of candidate residual shell units according to an embodiment of this application; Figure 10 This is a flowchart illustrating the explicit connection-first cleanup-implicit compensation-second cleanup closed-loop process described in the embodiments of this application. Figure 11 This is a schematic diagram of the final connection result described in the embodiments of this application; Figure 12 This is a schematic diagram of a feature shell mesh and backplate shell mesh fusion system according to an embodiment of this application; Figure 13 This is a schematic diagram of the hardware structure of the electronic device described in an embodiment of this application. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0013] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0014] The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0015] Please see Figure 1 As shown, this embodiment provides a method for fusing feature shell meshes and backplate shell meshes, specifically including the following steps: Step S10: Obtain the set of feature shell elements, the set of feature connecting edges, and the set of backplate shell elements. Divide the set of backplate shell elements into multiple non-overlapping backplate partitions and establish the mapping relationship between the backplate shell elements and the partitions.

[0016] Specifically, in this embodiment, the purpose of this step is to obtain the mesh entity and establish the backplane partition. Obtain the feature shell cell set. Featured Connecting Edge Set and backplate shell unit assembly , where the set It contains all the feature shell units to be fused, and the set It contains all the edges to be connected in the feature shell unit, set It contains all the backplate shell units to be connected.

[0017] This embodiment divides the backplate shell element set into groups based on the region affiliation and topological continuity of the backplate shell elements. A set of non-repeating backplate shell units: ; In the formula, Indicates the total number of backplane partitions; It is the partition number, and its value is... to ; Indicates the first The set of backplate shell elements within each partition. Union notation. This means that merging the partitions will exactly restore the complete set of backplane shell units. ; A mapping relationship is established between each backplane shell unit and a unique partition number, with no repetition between partitions, to avoid the same backplane shell unit being connected repeatedly.

[0018] Step S20: By performing explicit penetration detection on the feature shell unit set and the backplate shell unit set and establishing intersection correlation, a feature intersecting shell unit set is obtained. A local plane is constructed for each feature shell unit in the feature intersecting shell unit set to determine the effective backplate edge and effective intersection point intersecting with the local plane.

[0019] Specifically, in this embodiment, the purpose of this step is to obtain the intersection relationship between the feature shell unit and the backplate shell unit, and to construct a local plane and determine the effective backplate edges and effective intersection points intersecting with the local plane. The specific steps include: Step S201: Perform explicit penetration detection and establish intersection correlation.

[0020] Specifically, explicit penetration detection is performed on the set of feature shell elements and the set of backplate shell elements. Penetration detection is used to screen candidate feature shell elements and candidate backplate shell elements. Geometric intersection is used to determine the association pairs of candidate feature shell elements and candidate backplate shell elements that have common points. Based on the association pairs, a set of intersecting feature shell elements is formed. The intersection relationship can be expressed as: ; In the formula, This represents all candidate binary pairs consisting of any feature shell unit and any backplate shell unit; This represents one of the characteristic shell units. This represents one of the backplate shell units; Represents the internal region of a shell unit; This indicates a request for intersection; This indicates that there is at least one common point between the two. This represents the record of intersection relationships after geometric confirmation.

[0021] Depend on The set of characteristic intersecting shell elements is obtained: ; In the formula, there exists a quantifier. This means "at least one exists"; therefore, as long as some Composed of at least one backplate shell unit The related pairs in the middle, That is, to be added . It is a set, not a single shell unit; subsequent steps process its members one by one. If This indicates that no dominant intersecting shell elements to be connected were detected, thus ending the first dominant intersection phase.

[0022] Step S202: Construct the local plane of the feature shell unit to be processed.

[0023] Specifically, for Its vertex set is: ; In the formula, Characteristic shell unit The set of vertex coordinates; Indicates the first The three-dimensional coordinates of each vertex; The number of vertices is used to determine the triangular unit. Quadrilateral unit . This represents a set or sequence of vertices from which subsequent normals, center points, and local planes are calculated.

[0024] The unit normal vector of a triangular shell element is represented as: ; In this normal vector formula, and It is the edge vector pointing from the first vertex to the other two vertices; The cross product is represented by a vector perpendicular to the plane containing the triangle; the denominator is... It is the L2 norm of the cross product vector, used to normalize it to a length of 1. .

[0025] For quadrilateral shell elements or slightly non-coplanar shell elements, first calculate the vertex centers. It is the reference point of the local plane; then the covariance matrix is ​​constructed from the deviations of each vertex relative to this center. . The unit eigenvector corresponding to the smallest eigenvalue represents the direction with the smallest vertex dispersion, and therefore serves as the plane normal vector that best fits the shell element. Therefore, the local plane formula is constructed as follows: ; In plane equations middle, Represents the coordinates of any point on the plane. This represents the displacement of a point relative to a reference point; a dot product of zero indicates that the displacement is perpendicular to the normal vector; all points satisfying this equation... Together they form the local plane of the characteristic shell unit.

[0026] It should be noted that, regardless of whether it is a triangle or a quadrilateral, the local planar reference point is uniformly defined as the center of the vertex. .

[0027] Step S203: Locate the effective back panel edge and effective intersection point.

[0028] For characteristic intersecting shell units , from intersecting and related sets Directly obtain the corresponding candidate backplate shell element set: In the formula, It is a set of backplate shell elements that intersect with the current feature shell element; extracting only the edges in this set can narrow down the candidate range.

[0029] Extract candidate backplate edges from the candidate backplate shell element set. , and These are the two endpoints of the edge, and their parametric equations are: ; In the formula, the parameter Indicates the position on the line segment: Corresponding endpoints , Corresponding endpoints , The corresponding interior points between the two endpoints. Let the points of this line segment satisfy the plane equation from step three, and the intersection point parameters can be obtained: ; exist In the formula, the numerator measures the endpoints. The denominator measures the component of the backplate edge direction in the local normal direction relative to the local plane, representing the directional offset. When the absolute value of the denominator is not greater than this tolerance, the backplate edge is approximately parallel to the local plane, and unstable intersections are not calculated. , And the intersection point The distance from both endpoints is greater than the tolerance. Continue to judge Whether it is located within the finite polygon of the feature shell element. This indicates the tolerance for parallel decision-making.

[0030] Aggregate the valid intersection points according to the backplate edge endpoints to obtain: ; In the formula, the triplet To generate the backplate edge of the intersection point, The effective intersection point of the backplate edge and the local plane of the characteristic shell element. This represents the set of shell elements that contain the same backplate edge. The number of elements in this set reflects the edge sharing relationship: one element represents a boundary edge, and two elements usually represent an internal edge shared by two shell elements. A schematic diagram of the intersection point between the characteristic shell element set and the backplate edge segment is shown below. Figure 2 As shown.

[0031] Step S30: In response to the effective backplane edge being shared by two backplane shell units belonging to different backplane partitions, the effective backplane edge is determined as a cross-partition shared edge, and the endpoint of the shared edge that is closest to the effective intersection point is snapped to the effective intersection point.

[0032] Specifically, in this embodiment, the purpose of this step is to identify cross-partition shared edges and perform nearest node adsorption. This is achieved by recording each valid intersection point output from step S20. First, check the sharing relationships: ; In the formula, and Representing sets Shared back panel edge The first and second backplate shell units; superscript , It is only used to distinguish between two shell units and does not indicate the number of iterations, priority, or spatial direction. Represents a set The number of elements. Only when it is equal to 2, it means that the candidate edge is used by the two backplane shell elements mentioned above, and it may become a partition boundary edge that needs to be processed; if it is equal to 1, it means that the edge is a backplane boundary edge; if it is greater than 2 or the endpoint correspondence cannot be determined, the record is skipped to avoid moving nodes on non-manifolds or anomalous topologies.

[0033] For each of the two shared shell units, query its unique backplane partition number. Define the partition assignment function: ; In the formula, The input is a single backplate shell element, and the output is the partition number to which that shell element belongs. Since a unique partition mapping has been established in step S10, the same backplane shell unit corresponds to only one .

[0034] when When established, it indicates that the two sides of the shared edge belong to different backplane partitions. It was determined to be a cross-partition shared edge. A diagram illustrating the cross-partition shared edge identification is shown below. Figure 3 As shown; conversely, if both sides are in the same partition, node snapping is not performed, and the original node coordinates are directly retained.

[0035] For identified cross-partition shared edges, read their two actual grid endpoints. , and the intersection point obtained in step S203 ,calculate: ; In the formula, Represents three-dimensional Euclidean distance; Endpoints Distance to the intersection point Endpoints Distance to the intersection point. Select the node to be moved based on the distance comparison: ; Fixed endpoint selection during equidistant intervals This makes the algorithm deterministic. Then... The coordinates are updated to : ; In the formula, Represents the three-dimensional coordinates of the mesh node to be moved. This indicates a coordinate writing operation, not a numerical equality relationship. This operation only moves the endpoint of the shared edge that is closer to the intersection point; it does not add a new node, change the other endpoint, or process shared edges within the same partition. This solidifies the geometric intersection point, originally located inside the edge, into a real backplane mesh node that can be directly used in subsequent intersection and bonding operations, while minimizing local mesh distortion. A schematic diagram of the nearest node and node snapping on a cross-partition shared edge is shown below. Figure 4 and Figure 5 As shown.

[0036] Step S40: Perform the first intersection connection between the pre-corrected feature shell elements and each backplane partition in sequence, and determine the retained side and local backplane reference plane based on the pre-marked backplane source shell element set, and delete the feature source residual shell elements located on the deletion side or approximately overlapping with the backplane.

[0037] Specifically, in this embodiment, the purpose of this step is to achieve the first explicit intersection connection and the first residual shell element cleanup, cleaning up the intersection remnants based on the globally preserved side and the local backplate reference plane. This includes the following: After completing the intersection pre-correction, the current characteristic shell element is... Execute sequentially with each backplane partition: ; In the formula, Indicates the current feature shell unit and the first The returned entity set after performing an intersection operation on each backplane partition. This is achieved through comparison. Units before intersection It can distinguish between three states: "Connection not found," "Call did not change the topology," and "Connection result produced." Define the connection state: ; In this piecewise function, This indicates that an empty string was returned, meaning that no usable intersections were formed in the current partition. This indicates that the returned result is still only the original cell. This means that the intersecting calls did not cause any actual mesh changes; This indicates that a new, split, or replaced entity was found in the returned data, thus confirming that the current feature shell unit has successfully connected for the first time. Upon success, it stops attempting to connect to other backplane partitions and re-executes the penetration detection.

[0038] After the first explicit intersection phase, the failed shell elements from this phase are not directly used as the objects for the second connection. Instead, in the current model after the first residual cleanup, the implicit edges to be connected are re-identified based on the topological relationship between the feature connection edges and the backplate free boundary. A schematic diagram of the implicit edges to be connected is shown below. Figure 6 As shown. This represents the number of edges in the current feature connection set, used as the upper limit for the maximum number of processing rounds. If none of the candidate units produce a valid change in a single processing round, or if the number of processing rounds reaches this upper limit, the first explicit intersection phase ends. A diagram of the compensated connection is shown below. Figure 7 As shown.

[0039] The shell elements in the current model formed by retaining, splitting, or replacing the original backplate shell elements are marked as the backplate source shell element set. Step S30 has completed the intersection of node adsorption, and its corresponding real mesh node position is used as the local processing point. ; For each local processing point, extract the set of neighboring shell elements: ; In the formula, Indicated by intersection point The set of locally adjacent shell elements centered at the intersection; the condition after the vertical line indicates that only shell elements adjacent to this intersection point are retained. This neighborhood is divided according to shell element origin, with the backplate origin neighborhood set and the feature origin candidate residual set as follows: ; ; use Fit all vertices to the global backplane reference plane, and calibrate the global normal based on the side where the centroid of most feature shell elements is located. , so that it points to the side where the feature shell unit is retained; Reuse The vertex is fitted with the local backplane reference plane of the intersection neighborhood, and the local normal is adjusted to be consistent with the local backplane reference plane of the intersection neighborhood. In the same direction, we get Therefore, the sign of the subsequent distance has the same meaning at different intersection points: the positive side is the side to be retained, and the negative side is the side to be deleted.

[0040] For any candidate residual shell element Calculate its centroid Signed distance relative to the local reference plane: ; In the formula, It is the center point on the local backplate reference plane, dot product Give the zone-direction distance from the centroid of the candidate shell element to the plane; positive values ​​are on the reserved side, and negative values ​​are on the opposite side. According to the distance tolerance... Classification: ; In the formula, This indicates a cell located on the reserved side at a distance greater than the positive tolerance. This indicates a cell located on the error side with a distance less than the negative tolerance. Indicates an absolute distance not exceeding Units that approximately overlap with the back panel are therefore retained. Class unit, delete Class and Class unit. Candidate residual shell unit / Classification diagram as follows Figure 8 As shown, candidate residual shell elements Classification diagram as follows Figure 9 As shown.

[0041] Step S50: Re-identify the feature connection edges that do not match the free boundary of the backplane, perform a second intersection connection on the feature shell elements associated with the feature connection edges, and clean up the residual shell elements generated by the connection again to obtain the fusion model of the continuous topology.

[0042] Specifically, in this embodiment, such as Figure 10 As shown, the purpose of this step is to identify implicit edges to be connected, perform a second connection and a second residual cleanup, and output a fused model of the continuous topology. Specifically, it includes the following: After the first residual cleanup is completed, the current feature connection edge set is reread. Free boundary set Calculate the geometric centers of the feature connecting edges and the free boundary of the back plate, respectively: ; In the formula, This represents the set of current feature-connected edges after the first cleanup. This represents the set of free boundaries of the current backplate source shell element; and These represent one feature edge and one free boundary of the backplate, respectively. This represents the geometric center of the entity. Both equations map the edge or boundary to a three-dimensional center coordinate system for matching and determining the current topology.

[0043] make A tolerance is set for geometric center matching; if the distance between the geometric center of a feature connection edge and the geometric center of any backplate free boundary is greater than this tolerance, then the edge is identified as a hidden edge to be connected. ; in, Indicates "for any". Indicates the geometric center matching tolerance. This indicates that the feature connection edge does not match the free boundary of the backplate. Therefore... Collect feature edges that were not identified or completed in the first explicit intersection phase and do not yet correspond to the backplane boundary in the current topology. Use a set of processed edges to prevent the same edge from being repeatedly tried in multiple rounds of processing; the maximum number of processing rounds is preset to 6, and the second connection processing ends after the upper limit is reached.

[0044] For each unprocessed implicit edge to be connected Based on the assignment of its two endpoints in the feature shell mesh, the associated feature shell element is obtained: ; In the formula, Characteristic shell unit Boundary; containment relationship Representing an edge It is part of the boundary of the shell unit. Therefore, It is the set of feature shell elements containing the currently implicit edges to be connected. This set and each backplane partition... Perform the intersection joins sequentially; When the result involves addition, splitting, replacement, or other geometric or topological changes, the current implicit edge to be connected is determined to be successfully connected, and the traversal of other backplane partitions for that edge is stopped. In each round, the current feature connection edge and the backplane free boundary are reread until there are no unprocessed implicit edges to be connected or the preset maximum number of processing rounds is reached.

[0045] After the second connection is completed, the process of identifying the source shell unit of the backplate, calibrating the reserved side, and fitting the local plane is repeated. , , Classification rules are used to clean up erroneous sides and approximately overlapping residual shell elements generated by the second connection.

[0046] Output the final fusion model The model satisfies the following: ① Key intersections at cross-partition shared edges have been transformed into real mesh nodes; ② Feature shell elements and backplate shell elements have completed partitioned intersection connections; ③ Residual shell elements from erroneous sides and approximately overlapping feature sources have been deleted; ④ Feature connection edges and backplate boundaries form a continuous topological relationship. A schematic diagram of the final connection result is shown below. Figure 11 As shown.

[0047] The method described in this embodiment divides the back shell mesh into partitions and identifies cross-partition shared edges during the intersection of the feature shell mesh and the back shell mesh. It then snaps the real mesh nodes on the shared edges that are closer to the effective intersection point to the intersection point, transforming the geometric intersection point into a real node that can directly participate in subsequent intersection connections. This improves the connection success rate at the boundary of complex partitions and reduces local mesh distortion caused by node adjustments. Based on this, by dividing the intersection and connecting the residual shell elements and combining the global reserved side and the local backplate reference plane, the erroneous side and the approximately overlapping residual elements can be automatically removed. Furthermore, the implicit edges to be connected are compensated and secondary residual cleanup is performed, thus forming a complete automatic processing closed loop. This improves the topological continuity, connection stability and processing efficiency after the feature shell mesh and the backplate shell mesh are fused, and reduces the manual movement of nodes, repeated connections and manual cleanup work.

[0048] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0049] Based on the same inventive concept, corresponding to any of the above embodiments, the embodiments of this application also provide a feature shell mesh and backplate shell mesh fusion system.

[0050] like Figure 12 As shown, the feature shell mesh and backplate shell mesh fusion system includes: The partitioning module 11 is configured to obtain the feature shell unit set, the feature connection edge set, and the backplate shell unit set, divide the backplate shell unit set into multiple non-overlapping backplate partitions, and establish the mapping relationship between the backplate shell units and the partitions. The local plane construction module 12 is configured to obtain a set of intersecting shell elements by performing explicit penetration detection on the set of feature shell elements and the set of backplate shell elements and establishing intersection associations, and to construct a local plane for each feature shell element in the set of intersecting shell elements to determine the effective backplate edges and effective intersection points that intersect with the local plane. The explicit connection module 13 is configured to, in response to the effective backplane edge being shared by two backplane shell units belonging to different backplane partitions, identify the effective backplane edge as a cross-partition shared edge and snap the endpoint of the shared edge that is closest to the effective intersection point to the effective intersection point. The residual cleanup module 14 is configured to sequentially perform the first intersection connection between the pre-corrected feature shell units and each backplane partition, and determine the retention side and local backplane reference plane based on the pre-marked backplane source shell unit set, and delete the feature source residual shell units located on the deletion side or approximately overlapping with the backplane. The compensation connection module 15 is configured to re-identify the feature connection edges that do not match the free boundary of the backplane, perform a second intersection connection on the feature shell elements associated with the feature connection edges, and clean up the residual shell elements generated by the connection again to obtain a fusion model of continuous topology.

[0051] For ease of description, the above system is described by dividing it into various modules based on their functions. Of course, in implementing the embodiments of this application, the functions of each module can be implemented in one or more software and / or hardware.

[0052] The system described in the above embodiments is used to implement the corresponding method in any of the foregoing embodiments and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0053] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, embodiments of this application also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the methods described in any of the above embodiments.

[0054] Figure 13 This embodiment illustrates a more specific hardware structure of an electronic device, which may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0055] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0056] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0057] The input / output interface 1030 is used to connect input / output modules to realize information input and output. The input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touch screens, microphones, various sensors, etc., and output devices may include displays, speakers, vibrators, indicator lights, etc.

[0058] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0059] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0060] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0061] The electronic devices described above are used to implement the corresponding methods in any of the foregoing embodiments and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0062] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium that stores computer instructions for causing the computer to perform the methods described in any of the above embodiments.

[0063] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0064] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to perform the methods described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0065] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0066] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the claims of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A method for fusing feature shell meshes and backplate shell meshes, characterized in that, include: Obtain the set of feature shell units, the set of feature connecting edges, and the set of backplate shell units. Divide the set of backplate shell units into multiple non-overlapping backplate partitions and establish a mapping relationship between the backplate shell units and the partitions. By performing explicit penetration detection on the set of feature shell units and the set of backplate shell units and establishing intersection correlation, a set of intersecting feature shell units is obtained. A local plane is constructed for each feature shell unit in the set of intersecting feature shell units to determine the effective backplate edge and effective intersection point intersecting with the local plane. In response to the fact that the effective backplane edge is shared by two backplane shell units belonging to different backplane partitions, the effective backplane edge is determined as a cross-partition shared edge, and the endpoint of the two endpoints of the shared edge that is closest to the effective intersection point is attached to the effective intersection point; The pre-corrected feature shell elements are sequentially connected to each backplate partition for the first time, and the retained side and local backplate reference plane are determined based on the pre-marked backplate source shell element set. The feature source residual shell elements located on the deletion side or approximately overlapping with the backplate are deleted. Re-identify the feature connection edges that do not match the free boundary of the backplane, perform a second intersection connection on the feature shell units associated with the feature connection edges, and clean up the residual shell units generated by the connection again to obtain the fusion model of the continuous topology.

2. The method according to claim 1, characterized in that, The step of performing explicit penetration detection on the feature shell unit set and the backplate shell unit set and establishing intersection correlation to obtain the feature intersecting shell unit set includes: Candidate feature shell units and candidate backplate shell units are obtained by performing explicit penetration detection screening, and the association pairs with common points inside the candidate feature shell units and the candidate backplate shell units are determined by geometric intersection, and a set of feature intersecting shell units is formed based on the association pairs.

3. The method according to claim 1, characterized in that, The constructed local plane includes: For a triangular feature shell element, the unit normal vector is determined based on the cross product of the two edge vectors. For quadrilateral feature shell elements or non-coplanar feature shell elements, a covariance matrix is ​​constructed based on the deviation of each vertex from the vertex center. The unit eigenvector corresponding to the smallest eigenvalue of the covariance matrix is ​​determined as the plane normal vector, and the vertex center is used as the reference point of the local plane.

4. The method according to claim 1, characterized in that, The determination of the effective backplate edge and effective intersection point intersecting with the local plane includes: Candidate edges of backplate shell units that intersect with feature shell units are extracted, and the candidate edges are represented as line segment parameter equations between endpoints. The intersection parameters are obtained based on the line segment parameter equations and the local plane equations. When a candidate edge is not parallel to the local plane, and the intersection point is located inside the candidate edge and within the finite polygon of the feature shell element, the corresponding candidate edge and intersection point are determined as valid backplate edge and valid intersection point.

5. The method according to claim 1, characterized in that, The first intersecting connection includes: The feature shell units that have completed node movement will sequentially perform intersection operations with each backplane partition; In response to changes in the mesh topology caused by the addition, splitting, or replacement of entities in the intersection results, the current feature shell element is determined to be successfully connected and the traversal of the remaining backplane partitions is stopped. After each round of processing, explicit penetration detection is re-executed until no feature shell units exist, no effective topological change is generated in the current round, or the preset number of processing rounds is reached.

6. The method according to claim 1, characterized in that, The feature source residual shell unit that is deleted located on the deletion side or approximately coincides with the back plate includes: Shell units formed by retaining, splitting, or replacing backplate shell units are marked as backplate source shell units; The global backplate reference plane is fitted using the backplate source shell element, and the global normal is calibrated based on the side where the centroid of most feature shell elements is located to determine the reserved side; For local processing points formed by node adsorption, the local backplate reference plane is fitted using the backplate source shell elements in its neighborhood and the local normal direction is unified. Based on the signed distance from the centroid of the candidate residual shell unit to the local backplate reference plane, it is divided into retained side units, deleted side units, and approximately coincident units. The retained side units are retained, and the deleted side units and approximately coincident units are deleted.

7. The method according to claim 1, characterized in that, The re-identification of the set of feature connected edges that do not match the free boundary of the backplane includes: After the first residual cleanup, the set of feature connected edges and the set of backplate free boundaries of the backplate source shell elements are re-obtained, and the geometric centers of the feature connected edges and the backplate free boundaries are calculated respectively. In response to the fact that the distance between the geometric center of a feature connection edge and the geometric center of any backplate free boundary is greater than a preset matching tolerance, the feature connection edge is determined as a hidden edge to be connected. Obtain the feature shell unit containing the implicit edge to be connected, and sequentially perform a second intersection connection with each backplate partition until there are no unprocessed implicit edges to be connected or the preset maximum number of processing rounds is reached.

8. A system for fusing feature shell meshes and backplate shell meshes, characterized in that, include: The partitioning module is configured to acquire a set of feature shell units, a set of feature connecting edges, and a set of backplate shell units, divide the set of backplate shell units into multiple non-overlapping backplate partitions, and establish a mapping relationship between the backplate shell units and the partitions. The local plane construction module is configured to obtain a set of intersecting shell elements by performing explicit penetration detection on the set of feature shell elements and the set of backplate shell elements and establishing intersection associations, and to construct a local plane for each feature shell element in the set of intersecting shell elements to determine the effective backplate edges and effective intersection points that intersect with the local plane. An explicit connection module is configured to, in response to the effective backplane edge being shared by two backplane shell units belonging to different backplane partitions, identify the effective backplane edge as a cross-partition shared edge and snap the endpoint of the shared edge that is closest to the effective intersection point to the effective intersection point. The residual cleanup module is configured to sequentially perform the first intersection connection between the pre-corrected feature shell units and each backplane partition, and determine the retention side and local backplane reference plane based on the pre-marked backplane source shell unit set, and delete the feature source residual shell units located on the deletion side or approximately overlapping with the backplane. The compensation connection module is configured to re-identify feature connection edges that do not match the free boundary of the backplane, perform a second intersection connection on the feature shell units associated with the feature connection edges, and clean up the residual shell units generated by the connection again to obtain a fusion model of continuous topology.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium, characterized in that, in, The non-transitory computer-readable storage medium stores computer instructions for causing a computer to perform the method described in any one of claims 1-7.

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