| With the rapid development of computer technology,CAD,CAE,cam,CAPP and other computer-aided technologies are widely used in the machinery manufacturing industry.Design model and process model are the key parts of CAD and CAPP technology.They need to be loaded and displayed through CAD software,which is inconvenient in practical application.Especially in the aspects of model analysis and exchange and 3D process result display,it is necessary to find a lightweight model browsing interaction method.At the same time,due to the complexity of mechanical model,it is also necessary to support the rendering and display of large-scale model.The web end is an ideal platform for lightweight display of 3D models.Based on the web interactive 3D technology,this paper studies the key technologies in the web end browsing interaction of complex 3D models and the visualization of 3D process.Facing the design model,sheet metal process,machining process and assembly welding process,a network browsing interaction system of complex 3D models is developed to support the use on PC end and mobile end,Solve the problem of lightweight display of design model and process model.The main research work of this paper is as follows:(1)Aiming at the problem that the web file of complex 3D model is too large and loaded too slowly,this paper studies the grid and lightweight processing technology of model data,adopts the grid model format of gltf and compresses it to reduce the total amount of model data;Optimize the storage and loading mode of model data,and adopt the combination of assembly information file and part file to reduce data redundancy;Using progressive loading method and multithreading technology,the final loading speed of the model on the web side has been greatly improved compared with that before processing.(2)Aiming at the problem of browsing and interaction of complex 3D models on the web,based on webgl technology and computer graphics,this paper realizes the effective control of scenes and models.According to the needs of the mechanical field,this paper studies and develops the interactive functions of model explosion,sectioning and so on;At the same time,through the application of grid object merging technology,grid object grouping rendering optimization technology,non real-time refresh rendering technology and standard parts hiding technology,the number of grid objects in Web 3D scene is effectively reduced,the web page frame rate is improved,and the interaction fluency is significantly improved.(3)Aiming at the web-based reconstruction of model view,PMI annotation,feature contour,disassembly animation and other data in design model and 3D process,this paper analyzes the definition and creation process of various types of data in CAD software and 3D process,analyzes them pertinently,and finally realizes the visual reconstruction of various types of3 D process data,which is basically consistent with that in CAD software.(4)Aiming at the needs of Web-based browsing and interaction of complex 3D models and web-based visualization of 3D process,a complex 3D model network browsing and interaction system is developed for design model,sheet metal process,machining process and assembly welding process,and compared with the original CAD software and 3D process.The model display and process display effects are basically consistent with those in CAD software and meet the application requirements. |
