A method and system for generating mesh in thin-walled parts

Abstract

The present invention belongs to the technical field of computer graphics, and specifically relates to a method and system for generating a mesh in a thin-walled part, including: based on a thin-walled part entity, a boundary representation structure is used to construct an attribute adjacency graph of the thin-walled part entity; based on the attribute adjacency graph of the thin-walled entity, a face detection algorithm is used to identify the area maximum value surface, and a valid face geometric face set is recursively obtained to construct a face group pair set; based on any face set in the face group pair set, virtual topology operations and mesh partitioning are performed to obtain a partitioned face set; based on all mesh nodes on the partitioned face set, a modified projection method is used to obtain projection nodes constructed with the corresponding face set, and the mesh node and mesh edge relationship is retained to generate a middle mesh. This method can generate a middle mesh with higher quality, efficiency, and robustness, and the mesh type and size are controllable, which improves the applicability and flexibility of the middle mesh.

Description

Technical Field

[0001] The invention belongs to the technical field of computer graphics, and in particular relates to a method and system for generating a grid in a thin-walled part. Background Art

[0002] In the field of surface generation of computer-aided engineering (CAE) models, for the mid-surface generation of thin-walled parts, current technology mainly focuses on two core directions. One is to first construct a continuous geometric mid-surface, and then perform meshing based on the geometric mid-surface to generate a mesh model of the thin-walled part; the other is to generate a single-layer solid tetrahedral mesh model of the thin-walled part through a specific algorithm, and then cut the tetrahedral mesh to obtain the initial model of the mid-surface mesh, and obtain the final mid-surface mesh through mesh optimization.

[0003] Regarding the second direction, there are certain limitations in the implementation process, which are specifically reflected in: generating a single-layer solid tetrahedral mesh model of thin-walled parts takes a long time and has certain requirements on computing resources; in the process of tetrahedral mesh cutting, different types of tetrahedral meshes need to match different cutting methods, and the mid-surface mesh obtained after cutting may have triangles and quadrilaterals coexisting, which not only affects the consistency of the mesh, but also generally leads to a decrease in mesh quality. Summary of the invention

[0004] The present invention provides a method and system for generating a mid-grid for a thin-walled part. The method constructs an attribute adjacency graph of a thin-walled part entity, obtains a valid face-to-face geometric face set to construct a face group pair set, performs virtual topology operations and mesh subdivision, and uses a modified projection method to obtain projection nodes corresponding to each mesh node. A mid-grid model is generated by combining the relationship between mesh nodes and mesh edges, so that the quality, efficiency and robustness of the generated mid-grid are higher, the mesh type and size are controllable, and the applicability of the mid-grid is improved.

[0005] A method for generating a mesh in a thin-walled part, comprising:

[0006] Based on the thin-walled part entity, the attribute adjacency graph of the thin-walled part entity is constructed by using the boundary representation structure;

[0007] Based on the attribute adjacency graph of thin-walled solids, a face detection algorithm is used to identify the maximum area face, and the valid face geometry face set is recursively obtained to construct the face pair set.

[0008] Based on the face group, perform virtual topology operation and mesh partitioning on any face set in the set to obtain a partitioned face set;

[0009] Based on all mesh nodes on the subdivided surface set, the modified projection method is used to obtain the projection nodes constructed with the corresponding surface set, and the relationship between mesh nodes and mesh edges is retained to generate the mid-mesh.

[0010] By constructing the attribute adjacency graph of the thin-walled part entity and obtaining the valid face-to-face geometric face set to construct the face group pair set, virtual topology operations and meshing are performed, and the projection nodes corresponding to each mesh node are obtained by the modified projection method. The mid-mesh model is generated by combining the relationship between the mesh nodes and the mesh edges. The generated mid-mesh has higher quality, efficiency and robustness, and the mesh type and size are controllable, which improves the applicability of the mid-mesh.

[0011] Furthermore, the attribute adjacency graph of the thin-walled part entity includes connection relationships and attribute information of each face, edge, and vertex of the thin-walled part.

[0012] Furthermore, the attribute adjacency graph based on the thin-walled entity adopts a face detection algorithm to identify the maximum area face, and recursively obtains a valid face geometric face set to construct a face pair set, including:

[0013] Based on the attribute adjacency graph of thin-walled solids, the maximum area value surface is identified;

[0014] Based on the adjacent faces of the identified maximum area face, recursively traverse each undetected adjacent face;

[0015] Combining the dihedral angles of the maximum area face and its adjacent faces, the adjacent faces whose dihedral angles are not within the preset angle range are defined as side faces and removed from the thin-walled solid model, while the adjacent faces within the preset angle range are retained and form a valid facing geometric face set with the maximum area face;

[0016] Based on all valid facing geometric face sets, the top face set and the bottom face set are obtained respectively, and a face pair set is constructed.

[0017] By using the attribute adjacency graph of thin-walled entities for fast detection and screening the adjacency graph defined as the side, the efficiency of face detection can be improved.

[0018] Furthermore, the preset angle range of the dihedral angle is [175°, 180°].

[0019] Furthermore, the virtual topology operation and meshing are performed on any face set in the face group set to obtain a meshed face set, including:

[0020] Select any face set in the face group pair set and use it as the source face set;

[0021] Based on the source face set, the virtual topology operation is used to suppress the geometric edges inside the source face set into virtual topology edges;

[0022] A meshing algorithm is used to mesh the surface set after the virtual topology operation to obtain a meshed surface set.

[0023] By using virtual topology operations to suppress the boundaries of geometric edges inside the source face set, the quality of face mesh generation can be significantly improved.

[0024] Furthermore, the mesh generation algorithm includes a triangle mesh generation algorithm, a quadrilateral mesh generation algorithm, and a triangle mesh and quadrilateral mesh mixed generation algorithm.

[0025] Different meshing algorithms can be selected for meshing according to specific practical needs, so as to improve the applicability and flexibility of the method.

[0026] Furthermore, based on all mesh nodes on the subdivided surface set, the modified projection method is used to obtain projection nodes constructed with the corresponding surface set, and the relationship between mesh nodes and mesh edges is retained to generate the intermediate mesh, including:

[0027] Based on any grid node on the subdivided surface set, a projection node constructed with a corresponding target surface set is obtained by using a modified projection method; the target surface set is another surface set corresponding to the source surface set;

[0028] Based on all the grid nodes on the section set, respectively obtain the projection nodes constructed by the corresponding target surface set;

[0029] Based on each grid node and its corresponding projection node, the relationship between grid nodes and grid edges is retained to generate a mid-grid.

[0030] By adopting the modified projection method to obtain the projection nodes corresponding to each grid node on the source surface set, and retaining the connection relationship between the grid nodes and the grid edges to generate the intermediate grid, it can retain the quality of the original grid without the need for complex grid operations, improve the stability and efficiency of the algorithm, and thus obtain a high-quality intermediate grid, and can reduce the subsequent grid optimization time.

[0031] Furthermore, the method of obtaining a projection node constructed with a corresponding target surface set by using a modified projection method based on any mesh node on the subdivided surface set includes:

[0032] Based on any mesh node on the set of meshing surfaces, define it as the first node;

[0033] Projecting the first node onto the corresponding target surface set to obtain a second node;

[0034] Based on the normal vector of the first node on the set of segmented surfaces, the intersection point between the first node and the set of target surfaces is defined as the third node;

[0035] Determine a projection plane by combining the first node, the second node, and the third node;

[0036] The intersection of the angle bisector formed by the third node, the first node, and the second node and the target surface set is defined as the fourth node;

[0037] The midpoint of the line connecting the first node and the fourth node is determined as the projection node.

[0038] A system for a method for generating a mesh in a thin-walled part, comprising:

[0039] An adjacency graph generation module is used to construct an attribute adjacency graph of a thin-walled part entity based on the thin-walled part entity and using a boundary representation structure;

[0040] A face pair building module is used to identify the maximum area face based on the attribute adjacency graph of the thin-walled solid, and recursively obtain the valid face-to-face geometric face set to build the face pair set;

[0041] A subdivision surface construction module, which is used to perform virtual topology operations and mesh subdivision on any face set in the set based on the face group, to obtain a subdivision surface set;

[0042] The middle grid generation module is used to obtain the projection nodes constructed with the corresponding face set based on all the grid nodes on the subdivided face set by using the modified projection method, and retain the relationship between the grid nodes and the grid edges to generate the middle grid.

[0043] The beneficial effects of the present invention are:

[0044] The present invention constructs an attribute adjacency graph of a thin-walled part entity, obtains a valid face-to-face geometric face set to construct a face group pair set, performs virtual topology operations and mesh subdivision, and adopts a modified projection method to obtain projection nodes corresponding to each mesh node. The intermediate mesh model is generated by combining the relationship between the mesh nodes and the mesh edges. The generated intermediate mesh has higher quality, efficiency, and robustness, and the mesh type and size are controllable, thereby improving the applicability of the intermediate mesh. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flow chart of the present invention;

[0046] Figure 2 A schematic diagram of the generation process of the attribute adjacency graph of the present invention;

[0047] Figure 3 is a flow chart of the face detection algorithm;

[0048] Figure 4 Schematic diagram of the initial model of the source surface set;

[0049] Figure 5 It is a model schematic diagram of the source surface set after the virtual topology operation;

[0050] Figure 6 It is a model schematic diagram of the set of subdivided surfaces;

[0051] Figure 7 Schematic diagram of the generation process of projection nodes;

[0052] Figure 8 Schematic diagram of the generation process of a single medium grid;

[0053] Fig. 9 Flowchart of the algorithm for generating the entire mesogrid;

[0054] Fig.10 A schematic diagram of the mid-grid generation for the first model;

[0055] Fig.11 Generate a schematic diagram for the mid-grid of the second model;

[0056] Fig.12 Schematic diagram for mid-grid generation of the third model;

[0057] Fig.13 It is a schematic diagram of the system structure in the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0060] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples, and a person of ordinary skill in the art can understand the specific meanings of the above terms in this application under specific circumstances.

[0061] Example 1

[0062] Figure 1The method is a method for generating a mid-mesh for a thin-walled part. The method constructs an attribute adjacency graph of the thin-walled part entity, obtains a valid face-to-face geometric face set to construct a face group pair set, performs virtual topology operations and meshing, and uses a modified projection method to obtain the projection nodes corresponding to each mesh node. The mid-mesh model is generated by combining the relationship between the mesh nodes and the mesh edges, so that the quality, efficiency, and robustness of the generated mid-mesh are higher, and the mesh type and size are controllable, thereby improving the applicability of the mid-mesh. The method includes the following steps:

[0063] S1: Based on the thin-walled part entity, the attribute adjacency graph of the thin-walled part entity is constructed using the boundary representation structure;

[0064] In this embodiment, the attribute adjacency graph of the thin-walled part entity includes the connection relationship and attribute information of each face, edge, and vertex of the thin-walled part. Figure 2 Shown is a schematic diagram of the generation process of the attribute adjacency graph of a thin-walled part entity.

[0065] S2: Based on the attribute adjacency graph of thin-walled entities, a face detection algorithm is used to identify the maximum area face, and a valid face geometry face set is recursively obtained to construct a face pair set;

[0066] In this embodiment, Figure 3 The flowchart shown is a process of obtaining a valid set of facing geometric faces using a facing detection algorithm, and the process specifically includes the following steps:

[0067] S21: Identify the maximum area surface based on the attribute adjacency graph of thin-walled entities;

[0068] S22: based on the adjacent faces of the identified maximum area face, recursively traverse each undetected adjacent face;

[0069] S23: combining the dihedral angles of the maximum area value surface and its adjacent surfaces, defining the adjacent surfaces whose dihedral angles are not within the preset angle range as side surfaces, and removing them from the thin-walled solid model, retaining the adjacent surfaces within the preset angle range, and forming a valid facing geometric surface set with the maximum area value surface;

[0070] In this embodiment, the preset angle range of the dihedral angle is [175°, 180°].

[0071] S24: Based on all valid facing geometric face sets, a top face set and a bottom face set are obtained respectively, and a face pair set is constructed.

[0072] S3: Based on the face group, perform virtual topology operation and mesh division on any face set in the set to obtain a meshed face set;

[0073] S31: Select any face set in the face group pair set and use it as a source face set;

[0074] In this embodiment, the top surface set is selected as the source surface set, and the bottom surface set is selected as the target surface set.

[0075] S32: Based on the source face set, a virtual topology operation is used to suppress the geometric edges inside the source face set as virtual topology edges to improve the generation quality of the face mesh.

[0076] S33: Using a meshing algorithm to mesh the face set after the virtual topology operation, to obtain a meshed face set.

[0077] It should be noted that the mesh generation algorithm includes a triangular mesh generation algorithm, a quadrilateral mesh generation algorithm, and a triangular mesh and quadrilateral mesh hybrid generation algorithm. In this embodiment, the triangular mesh generation algorithm is selected for mesh generation.

[0078] Figures 4 to 6 They are the initial model of the source surface set, the model of the source surface set after the virtual topology operation, and the schematic diagram of the subdivided surface set model. By using the virtual topology operation to suppress the boundaries of the geometric edges inside the source surface set, it is possible to significantly select different meshing algorithms for meshing according to specific actual needs, so as to improve the applicability and flexibility of the method.

[0079] S4: Based on all the mesh nodes on the subdivided surface set, the modified projection method is used to obtain the projection nodes constructed with the corresponding surface set, and the relationship between the mesh nodes and the mesh edges is retained to generate the middle mesh.

[0080] S41: Based on any mesh node on the subdivided surface set, a projection node constructed with a corresponding target surface set is obtained by using a modified projection method; the target surface set is another surface set corresponding to the source surface set;

[0081] S411: Based on source surface collection Any mesh node on the obtained set of mesh surfaces is defined as the first node ;

[0082] S412: The first node Project to the corresponding target surface set On, get the second node ;

[0083] S413: Based on the first node in the segmentation surface set The normal vector on , and its reverse extension line and target surface set The intersection point is defined as the third node ;

[0084] S414: Combine with the first node , second node and the third node , determine the projection plane;

[0085] S415: The third node , first node , second node The angle bisector formed With the target face set The intersection point is defined as the fourth node ;

[0086] S416: The first node With the fourth node The midpoint of the line connecting the selected grid nodes is determined as the projection node corresponding to the selected grid node. ;

[0087] Figure 7 The figure shows a schematic diagram of the projection node generation process.

[0088] S42: Based on all mesh nodes on the profile set, respectively obtain projection nodes constructed by the corresponding target surface set;

[0089] S43: Based on each mesh node and its corresponding projection node, the relationship between the mesh nodes and the mesh edges is retained to generate a middle mesh.

[0090] Figure 8 Shown is a schematic diagram of the single-mesh grid generation process.

[0091] By adopting the modified projection method to obtain the projection nodes corresponding to each grid node on the source surface set, and retaining the connection relationship between the grid nodes and the grid edges to generate the intermediate grid, it can retain the quality of the original grid without the need for complex grid operations, improve the stability and efficiency of the algorithm, and thus obtain a high-quality intermediate grid, and can reduce the subsequent grid optimization time.

[0092] Example 2

[0093] In this embodiment, if Fig. 9 As shown, a method for generating a mesh in a thin-walled part is provided, which comprises:

[0094] T1: Based on the thin-walled part entity, the attribute adjacency graph of the thin-walled part entity is constructed using the boundary representation structure;

[0095] T2: Based on the attribute adjacency graph of thin-walled entities, a face detection algorithm is used to identify the maximum area face, and a valid face geometry face set is recursively obtained to construct a face pair set;

[0096] T21: Detect and identify the maximum area surface based on the attribute adjacency graph of thin-walled entities;

[0097] T22: Based on the adjacent faces of the identified maximum area face, recursively traverse each adjacent face to be detected;

[0098] T221: When the detection identifies that the adjacent surface of the surface to be detected has been detected, the detection identifies the next adjacent surface;

[0099] T222: When the detection identifies that the adjacent surface of the surface to be detected has not been detected, execute T23;

[0100] T23: Detect and identify the dihedral angles of the maximum area face and its adjacent faces, and determine whether the dihedral angles are within a preset angle range;

[0101] T231: When the dihedral angle is not within the preset angle range, the adjacent face to be detected is defined as a side face and deleted from the thin-walled solid model;

[0102] T232: When the dihedral angle is within the preset angle range, the adjacent face of the face to be detected is retained as the adjacent face, and it is combined with the maximum area face to form a valid facing geometric face set, and T24 is executed;

[0103] T24: Repeat T22 to T23 until all adjacent surfaces to be detected are detected;

[0104] T25: Based on all valid facing geometric face sets, get the top face sets respectively and the bottom set , and construct a face group pair set;

[0105] T3: Based on the face group, perform virtual topology operation and mesh division on any face set in the set to obtain a meshed face set;

[0106] T31: Select any face set in the face group pair set and use it as the source face set;

[0107] T32: Based on the source face set, the virtual topology operation is used to suppress the geometric edges inside the source face set as virtual topology edges to improve the quality of the generated face mesh;

[0108] T33: Use a meshing algorithm to mesh the surface set after the virtual topology operation to obtain a meshed surface set;

[0109] T4: Based on all the mesh nodes on the subdivided surface set, the modified projection method is used to obtain the projection nodes constructed with the corresponding surface set, and the relationship between the mesh nodes and mesh edges is retained to generate the middle mesh.

[0110] T41: Based on any mesh node on the subdivided surface set, the modified projection method is used to obtain the projection node constructed with the corresponding target surface set; the target surface set is another surface set corresponding to the source surface set;

[0111] T411: Define any mesh node on the set of meshed surfaces as the first node;

[0112] T412: Project the first node onto the corresponding target surface set to obtain the second node;

[0113] T41:3: Based on the normal vector of the first node on the subdivided surface set, the intersection point between the first node and the target surface set is defined as the third node;

[0114] T414: Determine the projection plane by combining the first node, the second node and the third node;

[0115] T415: The intersection of the angle bisector formed by the third node, the first node, and the second node and the target surface set is defined as the fourth node;

[0116] T416: Determine the midpoint of the line connecting the first node and the fourth node as the projection node corresponding to the selected grid node;

[0117] T42: Based on all the grid nodes on the section set, T41 is repeatedly executed until the projection nodes corresponding to all the grid nodes are obtained;

[0118] T43: Based on each grid node and its corresponding projection node, the relationship between grid nodes and grid edges is retained to generate a mid-grid.

[0119] Example 3

[0120] In this embodiment, the middle mesh generation method of thin-walled parts is used to generate the middle meshes of different thin-walled parts models.

[0121] Specifically, Figures 10-12 Shown are schematic diagrams of mid-grid generation based on the first model, the second model, and the third model, respectively.

[0122] Example 4

[0123] Based on the same design concept, Fig.13 As shown, this embodiment provides a system for generating a mid-mesh for a thin-walled part, including an adjacency graph generation module, a face group pair construction module, a split face construction module and a mid-mesh generation module.

[0124] Specifically, an adjacency graph generation module is used to construct an attribute adjacency graph of a thin-walled part entity based on the thin-walled part entity and using a boundary representation structure;

[0125] Specifically, a face pair building module is used to identify the maximum area face based on the attribute adjacency graph of the thin-walled solid, and recursively obtain the valid face-to-face geometric face set to build the face pair set;

[0126] Specifically, a subdivision surface construction module is used to perform virtual topology operations and mesh subdivision on any face set in the set based on the face group to obtain a subdivision surface set;

[0127] Specifically, the middle grid generation module is used to obtain the projection nodes constructed with the corresponding face set based on all the grid nodes on the subdivided face set by using the modified projection method, and retain the relationship between the grid nodes and the grid edges to generate the middle grid.

[0128] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0129] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for generating a mesh in a thin-walled part, characterized in that: include: Based on the thin-walled part entity, the attribute adjacency graph of the thin-walled part entity is constructed by using the boundary representation structure; Based on the attribute adjacency graph of thin-walled solids, a face detection algorithm is used to identify the maximum area face, and the valid face geometry face set is recursively obtained to construct the face pair set. Based on the face group, perform virtual topology operation and mesh partitioning on any face set in the set to obtain a partitioned face set; Based on all mesh nodes on the subdivided surface set, the modified projection method is used to obtain the projection nodes constructed with the corresponding surface set, and the relationship between mesh nodes and mesh edges is retained to generate the middle mesh; The thin-walled entity-based attribute adjacency graph adopts a face detection algorithm to identify the maximum area face, recursively obtains a valid face geometric face set, and constructs a face pair set, including: Based on the attribute adjacency graph of thin-walled solids, the maximum area value surface is identified; Based on the adjacent faces of the identified maximum area face, recursively traverse each undetected adjacent face; Combining the dihedral angles of the maximum area face and its adjacent faces, the adjacent faces whose dihedral angles are not within the preset angle range are defined as side faces and removed from the thin-walled solid model, while the adjacent faces within the preset angle range are retained and form a valid facing geometric face set with the maximum area face; Based on all valid facing geometric face sets, the top face set and the bottom face set are obtained respectively, and the face group pair set is constructed; The method of performing virtual topology operation and meshing on any face set in the face group pair set to obtain a meshed face set includes: Select any face set in the face group pair set and use it as the source face set; Based on the source face set, the virtual topology operation is used to suppress the geometric edges inside the source face set into virtual topology edges; A meshing algorithm is used to mesh the surface set after the virtual topology operation to obtain a meshed surface set.

2. A method for generating a mesh in a thin-walled part according to claim 1, characterized in that: The attribute adjacency graph of the thin-walled part entity includes connection relationships and attribute information of each face, edge, and vertex of the thin-walled part.

3. A method for generating a mesh in a thin-walled part according to claim 1, characterized in that: The preset angle range of the dihedral angle is [175°, 180°].

4. A method for generating a mesh in a thin-walled part according to claim 1, characterized in that: The mesh generation algorithm includes a triangle mesh generation algorithm, a quadrilateral mesh generation algorithm, and a triangle mesh and quadrilateral mesh mixed generation algorithm.

5. The method for generating a mesh in a thin-walled part according to claim 1, characterized in that: The method of using a modified projection method to obtain projection nodes constructed with corresponding face sets based on all mesh nodes on the face set, retaining the relationship between mesh nodes and mesh edges, and generating a mid-mesh includes: Based on any grid node on the subdivided surface set, a projection node constructed with a corresponding target surface set is obtained by using a modified projection method; the target surface set is another surface set corresponding to the source surface set; Based on all the grid nodes on the section set, respectively obtain the projection nodes constructed by the corresponding target surface set; Based on each grid node and its corresponding projection node, the relationship between grid nodes and grid edges is retained to generate a mid-grid.

6. A method for generating a mesh in a thin-walled part according to claim 5, characterized in that: The method of obtaining a projection node constructed with a corresponding target surface set by using a modified projection method based on any grid node on the subdivided surface set includes: Based on any mesh node on the set of meshing surfaces, define it as the first node; Projecting the first node onto the corresponding target surface set to obtain a second node; Based on the normal vector of the first node on the set of segmented surfaces, the intersection point between the first node and the set of target surfaces is defined as the third node; Determine a projection plane by combining the first node, the second node, and the third node; The intersection of the angle bisector formed by the third node, the first node, and the second node and the target surface set is defined as the fourth node; The midpoint of the line connecting the first node and the fourth node is determined as the projection node.

7. A system for the method for generating a mesh in a thin-walled part according to claim 1, characterized in that: include: An adjacency graph generation module is used to construct an attribute adjacency graph of a thin-walled part entity based on the thin-walled part entity and using a boundary representation structure; A face pair building module is used to identify the maximum area face based on the attribute adjacency graph of the thin-walled solid, and recursively obtain the valid face-to-face geometric face set to build the face pair set; A subdivision surface construction module, which is used to perform virtual topology operations and mesh subdivision on any face set in the set based on the face group, to obtain a subdivision surface set; The middle grid generation module is used to obtain the projection nodes constructed with the corresponding face set based on all the grid nodes on the subdivided face set by using the modified projection method, and retain the relationship between the grid nodes and the grid edges to generate the middle grid.

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