Triangle Bezier curved surface-based method for fairing STL model of products

Abstract

The invention provides a triangle Bezier curved surface-based method for fairing a STL model of products, which is characterized in that: firstly, adjacent region triangular patch cluster of a triangular patch is inquired; self-adapting clustering of the adjacent region triangular patch cluster is performed according to a normal vector included angle of the triangular patches in the adjacent region triangular patch cluster; self-adapting product STL model simplification is performed; the normal vector and the area of a grid peak topology adjacent region triangular patch in a simplified product STL model are solved; the normal vectors of peaks of the simplifying product STL model are worked out; a cubic triangle Bezier patch is formed according to the peak position and normal vector of triangle patch in the simplified model; the cubic triangle Bezier patch is elevated to a quintic triangle Bezier patch which is faired and spliced; the quintic triangle Bezier patch is scattered evenly to obtain a faired STL model of products; and the fairness disposal of the STL model of the products is realized. Instances prove that the method has high data adaptability and can effectively fairing the STL model of the products.

Description

technical field [0001] The invention provides a smoothing method of a product STL model based on a triangular Bézier curved surface, belonging to the field of product reverse engineering. Background technique [0002] The physical surface of the product is scanned by measuring equipment to obtain scattered point cloud data, and the point cloud data is triangulated to generate an STL model. This model is widely used in the field of rapid prototyping because of its fast flexibility and strong topology adaptability. The smoothness of the STL model obtained by interpolation is poor, and it cannot accurately describe the product surface characteristics. Research on the smoothing method of the STL model is of great significance for improving the accuracy and smoothness of the model. [0003] Retrieval of existing technologies found that Yin Wangzhong et al published in the academic journal "Mechanical Science and Technology" 2006, 25(4), P410-414 in the paper "Triangular Mesh Mode...

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Problems solved by technology

[0002] The physical surface of the product is scanned by measuring equipment to obtain scattered point cloud data, and the point cloud data is triangulated to generate an STL model. This model is widely used in the field of rapid prototyping because of its fast flexibility and strong topology adaptability. The smoothness of the STL model obtained by interpolation is poor and cannot accurately describe the characteristics of the product surface. Research on the smoothing method of the STL model is of great significance for improving the accuracy and smoothness of the model

[0003] Retrieval of existing technologies found that Yin Wangzhong et al published in the academic journal "Mechanical Science and Technology" 2006, 25(4), P410-414 in the paper "Triangular Mesh Model Smoothing Based on Triangular Surface Normal Vector Adjustment" , adjust the normal vector of the current triangle according to the change rate of the angle between the neighborhood triangle and the normal vector of the current triangle, and adjust the position of the vertices of the model according to the normal vector of the triangle. This method can realize the smoothing of the STL model, but it is difficult Effectively retain the detailed features of the STL model, and the accuracy of the model is low after smoothing

[0004] In the paper "A Smoothing Method for Triangular Meshes Preserving Features" published in the academic journal "Computer Engineering and Applications" 2006, 42(2), P58-60, Ping Xueliang et al. adopted different methods by identifying model features Dealing with the smoothing of feature areas and non-feature areas, this method can effectively preserve the details of the model, but the local smoothing effect on the model is poor

[0005] In the paper "Research on Fairing Algorithm for Mesh Model Based on Feature Repair" published in the academic journal "Mechanical Science and Technology" 2004, 23(1), P110-112, Nie Junhong et al. repeated the triangular patch method in the model Non-linear adjustment of vectors and grids to repair features such as edges in the model, but it is difficult to effectively smooth the model surface in areas with large curvature

[0006] In the paper "Mesh Smoothing with Uniform Principal Curvature" published in the academic journal "Journal of Computer Science" 2004, 27(1), P79-84, Liu Shenglan and others estimated the principal curvature of the vertices of the grid by establishing a local parabolic quadratic surface, using The idea of ​​weighted averaging is to find the curvature value of the vertices after smoothing, and adjust the position of the vertices of the grid. This method is easy to expand the detailed features of the model and cause the model to deform

[0007] To sum up, the existing product STL model smoothing methods cannot well realize the smoothing process of the product STL model, and it is difficult to effectively retain the detailed features of the model, and the model accuracy is not high after smoothing

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