CAD / CAE-oriented multi-model file format browser construction system

Abstract

The invention relates to a CAD / CAE (computer-aided design / computer-aided engineering)-oriented multi-model file format browser construction system, which comprises a multi-format model file analysis module, a general data structure conversion module, a multi-view model rendering module, a model control and interaction module and a model management and comparison module. Uniform reading, accurate analysis, efficient conversion and multi-dimensional interactive visualization of various mainstream and specific field engineering model formats such as STL, OBJ, STEP / STP, IGES / IGS, RTH and INP can be realized, and a model display function under various view angles such as entities, grids, point clouds and wireframes is provided, so that the problem of multi-format model data processing is effectively solved, and the engineering collaboration efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of computer-aided design and computer-aided engineering, and particularly relates to a CAD / CAE-oriented multi-model file format browser construction system. BACKGROUND

[0002] With the wide application of computer-aided design (CAD) and computer-aided engineering (CAE) technologies, various formats of three-dimensional model files are generated in the engineering design and analysis process. These different formats of files have different characteristics and application scenarios. However, the following problems may be encountered in visualization: ① The model file formats generated by different software systems are various, and it is difficult to convert them and there is a risk of data loss. ② The existing browser tools mostly only support a single or a few file formats, and cannot meet the needs of multiple formats coexisting in complex engineering environments. SUMMARY

[0003] In view of the above problems in the prior art, the present application provides a CAD / CAE-oriented multi-model file format browser construction system. By constructing a unified and efficient visualization platform, the unified reading, accurate analysis, efficient conversion and multi-dimensional interactive visualization of various mainstream and specific field engineering model formats such as STL, OBJ, STEP / STP, IGES / IGS, RTH and INP can be realized, and model display functions in various perspectives such as entity, mesh, point cloud and wireframe are provided, thereby effectively solving the problem of multi-format model data processing and improving engineering collaboration efficiency.

[0004] The present application is implemented by the following technical solutions:

[0005] The application relates to a CAD / CAE-oriented multi-model file format browser construction system, which comprises a multi-format model file analysis module, a general data structure conversion module, a multi-view model rendering module, a model control and interaction module and a model management and comparison module, wherein: the multi-format model file analysis module reads and analyzes different format model files and metadata according to inputted unified interfaces to obtain normalized geometric and topological information; the general data structure conversion module converts different format model files into a unified internal data structure and realizes diversified visual presentation of three-dimensional models by using a graphics rendering library (VTK); the multi-view model rendering module performs coloring and drawing of point cloud, mesh, entity and line frame (framework) modes according to display requirements and scene states of users to obtain multi-dimensional and switchable model visualization results; the model control and interaction module updates the interaction logic of the model according to user interaction events (rotation, translation, scaling, selection and the like) and the current view context to obtain stable and smooth model operation feedback; and the model management and comparison module supports opening of multiple models, so that reading, conversion and interactive visualization of multi-format data can be completed on a unified and efficient platform, and multi-view display of entities, meshes, point clouds and line frames and the like is provided to improve engineering collaboration efficiency.

[0006] The general model data structure refers to a Vector3 class representing a three-dimensional point and attributes thereof, a facet class representing a facet and associated information thereof and a Model class uniformly managing model data converted from different formats.

[0007] The model rendering and interaction refer to four display effects of point cloud, mesh, entity and framework realized by using VTK based on the saved model data structure, and the interface supports interaction by using a mouse, including basic operations such as zooming in and out, moving and rotating. Technical effects

[0008] The application successfully realizes integrated reading, conversion and display of various engineering file formats such as STL, OBJ, STEP, IGES, RTH and INP, effectively solves the problem of interactive processing of multi-format model files in the engineering design and analysis process, supports four different model display modes of point cloud, mesh, entity and framework, meets the visualization requirements of users in different engineering scenes, realizes interactive operations of model rotation, scaling, translation and accurate point selection and the like, and improves user experience. The application provides an all-in-one multi-format model browsing solution for engineering technical personnel, reduces format conversion cost and data loss risk, and significantly improves the work efficiency of cross-disciplinary collaborative design and analysis. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The application relates to a CAD / CAE-oriented multi-model file format browser construction system, which comprises a multi-format model file analysis module, a general data structure conversion module, a multi-view model rendering module, a model control and interaction module and a model management and comparison module, wherein: the multi-format model file analysis module reads and analyzes different format model files and metadata according to inputted unified interfaces to obtain normalized geometric and topological information; the general data structure conversion module converts different format model files into a unified internal data structure and realizes diversified visual presentation of three-dimensional models by using a graphics rendering library (VTK); the multi-view model rendering module performs coloring and drawing of point cloud, mesh, entity and line frame (framework) modes according to display requirements and scene states of users to obtain multi-dimensional and switchable model visualization results; the model control and interaction module updates the interaction logic of the model according to user interaction events (rotation, translation, scaling, selection and the like) and the current view context to obtain stable and smooth model operation feedback; and the model management and comparison module supports opening of multiple models, so that reading, conversion and interactive visualization of multi-format data can be completed on a unified and efficient platform, and multi-view display of entities, meshes, point clouds and line frames and the like is provided to improve engineering collaboration efficiency.

[0010] Figure 2 A schematic diagram of the model import function interface;

[0011] Figure 3 A schematic diagram of the STL file model is shown.

[0012] In the figure: taking STL files as an example, (a) shows the solid model, (b) shows the point cloud model, (c) shows the mesh model, and (d) shows the frame model;

[0013] Figure 4 A schematic diagram of the OBJ file model is displayed;

[0014] Figure 5 A schematic diagram of the STEP file model is displayed;

[0015] Figure 6 A schematic diagram of the IGES file model is shown;

[0016] Figure 7 A schematic diagram showing the RTH file model;

[0017] Figure 8 This is a schematic diagram of an INP file model. Detailed Implementation

[0018] like Figure 1 As shown, this embodiment illustrates the model browsing and construction method based on the aforementioned system. It is implemented using C++ language combined with Qt (a cross-platform graphical user interface application development framework) and the open-source 3D visualization toolkit VTK (Visualization Toolkit), specifically including:

[0019] Step 1: Design and Implementation of a General Data Structure

[0020] Design a unified internal data representation for storing and processing model data in different formats: Define a Vector3 structure to represent a point in 3D space, containing point coordinates, normal vectors, and associated information; define a facet structure to represent a triangular facet, containing information such as face normals, vertices, and area; implement a Model class as a model container to manage vertex and facet sets; and design a data conversion interface to enable the conversion between VTK polygon data and the internal data structure.

[0021] Based on the different imported file formats, corresponding file model parsing and processing are performed. The processing modules for different files are implemented as follows:

[0022] Step 2: Implementation of the STL format processing module:

[0023] 2.1 STL format processing adopts the native support scheme of VTK, and uses the vtkSTLReader component to read STL files (supporting binary and ASCII formats).

[0024] 2.2 Set the read polygon data vtkPolyData object into the Model object, and extract and store the vertex and face information of the model.

[0025] 2.3 Initial rendering representation of the generated model.

[0026] Step 3: Implementation of STEP and IGES format processing modules:

[0027] 3.1 Integrates the OpenCASCADE Technology library for processing STEP and IGES formats.

[0028] 3.2 For STEP files, use STEPControl_Reader to read and extract geometric and topological information; for IGES files, use IGESControl_Reader to read and parse geometric elements.

[0029] 3.3 The BRepMesh_IncrementalMesh algorithm is used to convert the B-REP representation into a triangular mesh, generating a temporary STL file as an intermediate format. The model is then loaded into the system through a unified STL processing flow, which is the same as the STL processing flow described above.

[0030] Step 4: Implementation of the OBJ format processing module:

[0031] The system adopts VTK's native support solution, using VTK's vtkOBJReader component to read OBJ files, extract geometric and coordinate information from the OBJ files, convert the read data into the system's internal representation format, and load the model into the system through a unified processing flow.

[0032] Step 5: Implementation of the INP format processing module:

[0033] 5.1 A line-by-line parsing strategy is adopted to create an input stream to read the file and identify key paragraphs in the file structure: parse the node segment, extract the node ID and coordinate information, and establish a mapping relationship from the node ID to the VTK point index; parse the element segment, construct the topological relationship according to the element type (such as hexahedron, tetrahedron), extract the element ID and the node ID that makes up the element, obtain the corresponding VTK point index through the node ID mapping table, and create the corresponding VTK element according to the element type;

[0034] 5.2 Create a vtkUnstructuredGrid to store unstructured grid data, and use vtkGeometryFilter to convert the unstructured grid into polygon data for visualization;

[0035] 5.3 Generate a temporary STL file as an intermediate format, use vtkSTLWriter to write polygon data into the temporary STL file, and use vtkSTLReader to reread the temporary STL file to unify the subsequent processing flow.

[0036] Step 6: RTH Format Processing Module Implementation: The system dynamically generates a Python script file, imports the ansys.mapdl.reader library, calls the read_binary method to read the RTH file, uses the plot_nodal_solution method to generate a temperature contour plot, starts the Python interpreter via QProcess to execute the script, and displays the generated temperature image upon completion.

[0037] Step 7: Implementation of interactive function modules:

[0038] Configure vtkInteractorStyleTrackballCamera to implement model rotation, scaling, and translation, and enable quick switching of preset viewpoints (front view, side view, top view, etc.). Develop vtkCellPicker to implement highlighting and information display of pick points.

[0039] The 3D model shown above represents common engine components and is realistically and effectively suited to the intended use case.

[0040] Compared with existing technologies, the main technological advancements of this invention are reflected in: ① Unified processing of CAD geometric formats and CAE analysis formats, establishing a seamless design-analysis data chain; ② High-precision processing capability for complex CAD geometry is ensured through OpenCASCADE integration; ③ The self-developed INP parser supports multiple element types, ensuring accurate reconstruction of finite element models; ④ The Python script integration scheme flexibly supports post-processing of various analysis results; ⑤ Multi-mode visualization and interactive functions meet the practical needs of engineering applications. This technical solution, while maintaining high compatibility, significantly improves data sharing and collaborative work efficiency in the design and analysis process, reduces project errors caused by format incompatibility, and provides powerful tool support for the digitalization of manufacturing.

[0041] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of the present invention. The scope of protection of the present invention is defined by the claims and is not limited to the above-described specific implementations. All implementation schemes within the scope of the claims are bound by the present invention.

Claims

1. A browser-based system for building multiple model file formats for CAD / CAE, characterized in that, include: The system comprises four modules: a multi-format model file parsing module, a general data structure conversion module, a multi-view model rendering module, a model control and interaction module, and a model management and comparison module. Specifically: the multi-format model file parsing module reads and parses input model files of different formats and their metadata using a unified interface to obtain standardized geometric and topological information; the general data structure conversion module converts different format model files into a unified internal data structure and utilizes a graphics rendering library to provide diverse visual representations of the 3D models; the multi-view model rendering module performs point cloud, mesh, solid, and wireframe coloring and rendering based on user display requirements and scene conditions to obtain multi-dimensional, switchable model visualization results; and the model control and interaction module updates the model's interaction logic based on user interaction events and the current view context to provide stable and smooth model operation feedback. The model management and comparison module reads, transforms, and interactively visualizes data on a unified and efficient platform.

2. The CAD / CAE multi-model file format browser construction system according to claim 1, characterized in that, The general model data structure refers to: a custom Vector3 class representing 3D points and their attributes, a facet class representing faces and their associated information, and a Model class that uniformly manages model data converted from different formats.

3. The CAD / CAE multi-model file format browser construction system according to claim 1, characterized in that, The aforementioned model rendering and interaction refers to the use of VTK to display point clouds, meshes, entities, and frames based on the saved model data structure, while simultaneously supporting zooming, moving, and rotating operations via mouse on the interface.

4. A method for constructing a browser for multiple model file formats according to any one of claims 1-3, characterized in that, include: Step 1: Construct a general data structure, including: defining a Vector3 structure to represent a point in 3D space, containing point coordinates, normal vectors, and associated information; defining a facet structure to represent a triangular facet, containing face normals, vertices, and area; implementing a Model class as a model container to manage vertex and facet sets; and designing a data conversion interface to enable the conversion between VTK polygon data and the internal data structure. Step 2: Based on the different imported file formats, perform corresponding file model parsing and processing.

5. The browser construction method for multiple model file formats according to claim 4, characterized in that, The file model parsing and processing mentioned above includes any of the following: A) STL format processing: Using the native VTK support solution, the vtkSTLReader component is used to read the STL file, set the read polygon data vtkPolyData object into the Model object, extract and store the vertex and face information of the model, and then generate the initial rendering representation of the model. B) STEP and IGES format processing: Integrate the OpenCASCADE Technology library, use STEPControl_Reader to read and extract geometric and topological information, use IGESControl_Reader to read and parse geometric elements for IGES files, use the BRepMesh_IncrementalMesh algorithm to convert B-REP representation into triangular mesh, generate temporary STL file as intermediate format, and load the model into the system through a unified STL processing flow; C) OBJ format processing: Adopting the native support solution of VTK, the vtkOBJReader component of VTK is used to read OBJ files, extract the geometric information and coordinate information in the OBJ files, convert the read data into the system's internal representation format, and load the model into the system through a unified processing flow; D) INP Format Processing: A line-by-line parsing strategy is used to create an input stream to read the file, identify key paragraphs in the file structure, construct topological relationships based on cell type, extract cell IDs and node IDs that make up the cell, obtain the corresponding VTK point index through the node ID mapping table, and create the corresponding VTK cell based on the cell type; after converting the unstructured mesh into polygon data for visualization using vtkGeometryFilter, a temporary STL file is generated as an intermediate format, the polygon data is written to the temporary STL file using vtkSTLWriter, and the temporary STL file is reread using vtkSTLReader to unify the subsequent processing flow; E) RTH format processing: The system dynamically generates a Python script file, imports the ansys.mapdl.reader library, calls the read_binary method to read the RTH file, uses the plot_nodal_solution method to generate a temperature contour plot, starts the Python interpreter through QProcess to execute the script, and displays the generated temperature image after completion; F) Interactive functions: Configure vtkInteractorStyleTrackballCamera to realize the rotation, scaling and translation of the model, realize the function of quickly switching preset viewpoints, and develop vtkCellPicker to realize the highlighting and information display of the pick point.

6. The method for constructing browsers for multiple model file formats according to claim 5, characterized in that, The key paragraphs identified in the file structure refer to: parsing node segments, extracting node IDs and coordinate information, and establishing a mapping relationship from node IDs to VTK point indices.

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