Method for simplifying three-dimensional geometric graphics on basis of triangle contraction

Abstract

The invention discloses a method for simplifying three-dimensional geometric graphics on the basis of triangle contraction. The method includes firstly, setting conditions for judging triangles and only allowing contraction operation to be carried out on triangles which meet the conditions; secondly, folding and contracting the triangles; thirdly, determining the vertexes V of contraction points with the maximum distances d, using average planes M as planes adjacent to points V and solving the contraction points by a secondary error process. The maximum distances d of the contraction points are equal to computation factors a. The folding and contraction priority of each triangle is represented by a weight L=aXb, the triangles corresponding to small weights L are contracted at first, each factor b represents the area of the corresponding triangle, each average plane M of a triangle plate S of the corresponding triangle T is computed, normal vectors of the average planes M are acquired in such a manner the maximum distances d from the various points V to the triangle plates S are used as the factors a, in other words, each d is equal to an absolute value of nX(V-x), each factor a is the maximum value of the corresponding distances d1, d2 and d3, and the distances d are used for solving the triangles T. The method for simplifying the three-dimensional geometric graphics on the basis of triangle contraction has the advantages that conditional judgment is carried out on the triangles, the triangles are folded and contracted according to priority levels of the triangles, accordingly, simplifying procedures can be optimized, the precision is high, and the original graphics can be effectively preserved.

Description

technical field [0001] The invention relates to the technical field of image processing, in particular to a three-dimensional geometric figure simplification method based on triangle shrinkage. Background technique [0002] The purpose of the simplification technology of the 3D geometric model is to reduce the data volume of the model. The simplification technology starts from the geometrical point of view, reduces the segmentation accuracy of the model surface and minimizes the number of divided polygons on the premise that the shape of the model is basically unchanged. The research direction of 3D polygonal surface model simplification technology mainly includes the following aspects: the simplification method of the model, what kind of method or operation can be used to reduce the number of polygons on the model surface; the control method of the error during model simplification, and what kind of method to use. In order to ensure that the simplified model is similar in a...

AI Technical Summary

Problems solved by technology

There are many ways of existing triangle contraction, the main problem is how to determine the priority of triangle contraction: an effective triangle folding algorithm proposed by Hamann is to determine the triangle’s Weight, the triangle with the lowest weight is first folded into a new point; another method is to select the maximum value of the distance between the new point and the plane where each triangle is located in the triangle set related to the folded triangle as the weight, and determine the triangle The folding order; other methods such as Isler determine the visual importance of vertices and triangles according to the area of ​​the triangle and the normal difference of the triangles around the vertices, and its simplified method uses the visual importance of vertices to determine the type of folding operation (edge ​​folding or triangle folding), and the visual importance of the triangles is used to determine the folding order of the triangles, but this method simply selects the vertices in the original mesh as the folding points, which is prone to large geometric errors

[0004] In summary, the existing 3D geometry simplification methods still have a lot of room for improvement, and a 3D geometry simplification method based on triangle shrinkage is urgently needed for optimization.

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