Deformation design method for product STL model

Abstract

The invention provides a deformation design method of a product STL model, which is characterized in that the approaching plane of an editing area of the product STL model is solved by adopting the least square method, the vertex of the product STL model is projected to the approaching plane to set up a local plane coordinate system of a projection point set and obtain an axial bounding rectangle with minimum area of the projection point set, the vertex of the product STL model is parameterized, the reference curved surface of the editing area is solved, the mapping relation between the vertex of the product STL model and the projection point on the reference curved surface is set up, the control vertex of the reference curved surface is adjusted, the displacement of the projection point is calculated, the vertex coordinate of the product STL model is adjusted according to the displacement of the projection point to finish the deformation of the editing area of the product STL model, a first-order geometric continuous triangular B * zier curved surface is constructed for the deformed model to realize smoothing treatment of the model, and a smoothed product STL model is obtained by dispersing the triangular B * zier curved surface to finish the deformation innovative design of the product STL model. The method can accurately control the model shape and effectively improve the smoothness and deformation design efficiency of the product STL model.

Description

technical field [0001] The invention provides a deformation design method of a product STL model, which belongs to the technical field of product reverse engineering. Background technique [0002] In product reverse engineering, equipment such as laser scanners is usually used to obtain scattered point cloud data on the surface of the product solid model, and the data is triangulated to generate an STL model, which approximates the original solid model, but in the subsequent implementation of the product based on the product STL model In the process of innovative design, it is often necessary to modify the reconstruction model. For this problem, at present, the reconstruction model is mainly converted into a NURBS surface model, and the model modification is realized in mainstream CAD systems (UGNX, CATIA, PRO / E, etc.). Since a large number of manual interactive surface modeling operations are required during the surface model conversion process and the loss of model accura...

AI Technical Summary

Problems solved by technology

In the academic paper "NURBS-based three-dimensional human body free deformation method" published in the academic journal "Computer Engineering and Application" 2002, 17(3), P95-97, Wang Jianzhe constructed a large enough three-parameter NURBS free body , embed the STL model of the product to be deformed into the free body, and adjust the control vertices of the free body to realize the deformation of the product STL model. This method can realize the overall deformation of the product STL model, but it is difficult to achieve local deformation control

In the academic paper "Partial Editing of 3D Mesh Based on Skeleton" published by Duan Dequan et al. in the academic journal "Computer Engineering and Application" 2006, 33(3), P88-90, the user first determines the editing area, and after drawing and deforming Editing curves corresponding to the skeleton, and then according to the corresponding relationship between the vertices of the STL model, the skeleton curve and the editing curve, the editing operations such as translation and rotation of the STL model nodes are realized. This method extracts the model skeleton and adjusts the endpoints of the skeleton. The model is partially deformed, but the detailed features of the model surface cannot be edited

In the academic paper "Mesh Model Deformation Technology Based on Hierarchical B-splines" published in the academic journal "Journal of Computer-Aided Design and Graphics" 2006, 18(3), P443-450, Zhou Tingfang et al. The base surface of the product STL model can be obtained by means of uniform resampling and hierarchical B-spline fitting of sampling points. By editing the hierarchical B-spline base surface or directly editing the product STL model, the detailed feature editing of the model surface can be realized. However, due to the lack of The edited product STL model is optimized, and the smoothness of the model is poor

In the academic paper "Local Editing Algorithm for Grid Model" published in the academic journal "Journal of Computer-Aided Design and Graphics" 2004, 16(4), P444-448, Qin Xujia and others used the approximation method to obtain the editing area control grid, Deformation design of the edited area after subdivision can realize local smooth deformation of the product STL model, but the deformation process needs to repeatedly calculate the vertex coordinates of the subdivision mesh, and the deformation calculation amount is large and the efficiency is low

[0004] In summary, the existing deformation design methods for product STL models have problems such as difficulty in editing local surface detail features of the model, poor smoothness of the model after editing, and low deformation efficiency.

Images