Method for identifying and combining broken surfaces of complex three-dimensional body

A complex and broken surface technology, applied in image data processing, 3D modeling, instruments, etc., can solve problems such as error-prone, large amount of calculation, and many broken surface nodes, so as to reduce the number of grids and improve the quality of grids , the effect of increasing the running speed

Inactive Publication Date: 2017-05-31
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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Problems solved by technology

[0004] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a method for identifying and merging complex three-dimensional body fragments. For complex three-dimensional bodies, the fragments generated during Boolean operations are small and dense, so The mesh quality of the three-dimensional body division is not high and is prone to errors, which may lead to the inability to complete the CFD calculation or obtain meaningless results, and there are many broken surface nodes and a large amount of calculation, which seriously affects the calculation efficiency and a series of problems. Invented A Method for Recognition and Combination of Fragments of Complex 3D Shapes

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  • Method for identifying and combining broken surfaces of complex three-dimensional body
  • Method for identifying and combining broken surfaces of complex three-dimensional body
  • Method for identifying and combining broken surfaces of complex three-dimensional body

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Embodiment

[0045] Such as figure 1 Shown are triangular fractals that form the surface of a complex 3D volume after Boolean operations. A method for identifying and merging complex three-dimensional shape fragments, such as figure 2 shown, including the following steps:

[0046] Step 1. Input the set of triangles that constitute the surface of the complex geometric part;

[0047] Step 2. Regularize the points in the triangle set that constitutes the surface of the complex geometric part, and determine the error value ε 0 , merge the points by calculating the distance between the two points, if the distance between the two points is less than ε 0 =10 -4 , at this time in the program, the naked eye can no longer see the distance error between the two points, then merge the two points into one point, such as image 3 shown;

[0048] Step 3. Take the triangle f 1 , f 2 As an example, determine whether a triangle has a common edge. Calculate triangle f 1The midpoint of the three si...

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Abstract

The invention discloses a method for identifying and combining broken surfaces of a complex three-dimensional body. The method comprises the steps of firstly inputting a triangle set which forms the surface of a complex geometric part; secondly judging whether triangles on the curved surface are edge-shared and surface-shared or not, if the triangles are edge-shared and surface-shared, combining the broken surfaces of the two triangles, and if the triangles are edge-shared only, not combining the broken surfaces; and finally reconstructing the triangles by utilizing a Delaunay triangulation method. According to the method, dense small triangles are combined, so that the complex three-dimensional body subjected to Boolean operation can be subjected to grid division conveniently, grid errors are not caused, grid nodes are reduced, the calculation amount is reduced, the program running speed is increased, and the efficiency is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of CFD-oriented three-dimensional complex body modeling, and in particular relates to a method for identifying and merging complex three-dimensional body fragments. Background technique [0002] When modeling a complex three-dimensional body, due to the complex structure of the model, a large number of Boolean operations are required on the model. During the operation process, the constructed model often has dense irregular fragments in a curved surface. These broken faces will seriously affect the accuracy and uniformity of meshing the model; and the small number of broken faces will take a long time to calculate and the efficiency will be low. [0003] Aiming at the above problems, the present invention proposes a method for identifying and merging complex three-dimensional shape fragments. The method adopts a certain fault-tolerant criterion to merge triangle sets constituting curved surfaces and regenera...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06T17/30
Inventor 赵璐刘勇
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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