A Edge-by-Edge Layering Method for Triangular Surface Model in Rapid Prototyping

Abstract

The invention discloses an edge-by-edge layering method of a triangular patch model in rapid forming. The method comprises the steps: firstly, removing redundant points based on triangular patch model data read into an internal storage, and establishing a forward edge table, information of a left connection patch of the forward edge table and information of a right connection patch of the forward edge table; then, traversing the model to acquire the maximum Z value and the minimum Z value in the layering direction, and working out the total number N of layers of the model according to a preset layer thickness; establishing a dynamic array with an intersection point connection auxiliary data structure, and a layering contour array, wherein both the length of the dynamic array and the length of the layering contour array are equal to number N of the layers; thirdly, traversing the forward edge table, selecting forward edges sequentially, working out the intersection points of the edges and an intersection layering plane sequentially based on the geometric continuity of the edges, and executing the intersection point connection algorithm immediately every time when one effective interaction point is worked out; finally, processing all the forward edges to obtain a layering contour line with the contour line direction meeting the left-hand rule. By means of the method, the layering efficiency can be effectively improved.

Description

technical field [0001] The invention relates to a side-by-side layering method of a triangular surface model in rapid prototyping. Background technique [0002] Rapid prototyping technology does not require complex production lines and tooling, and can form parts of any complex shape at one time, which greatly simplifies the manufacturing process, reduces production costs, and shortens the development cycle. Rapid prototyping technology is based on the principle of layered discrete / additive materials, so the layering of CAD models is the basis of the rapid prototyping process, and the research on layered algorithms has always been an important aspect in the field of rapid prototyping research. [0003] Due to the difference of CAD models, layering algorithms can be divided into two categories. (1) Direct layering algorithm of continuous surface model; (2) Layering algorithm of triangular patch model represented by STL model. This type of algorithm can only obtain discrete ...

AI Technical Summary

Problems solved by technology

Therefore, this kind of method can be collectively referred to as layer-by-layer (or layer-first) layering method. Its shortcoming is that it cannot make good use of the geometric continuity of edges in the model, so as to affect the layering efficiency.

This algorithm occupies less memory and does not repeatedly calculate the intersection point, but there are also factors that affect the layering efficiency, such as: because there is no adjacent topology information of the patch, each search of adjacent patches needs to go through multiple comparisons of vertex coordinates ; Since it is necessary to find the common edge and then calculate the intersection point, the geometric continuity of the edge is not used

[0005] In summary, the existing layer-by-layer layering methods and layer-by-face layering methods for triangular patch models cannot directly and effectively use the geometric continuity of edges for layering, which affects the layering efficiency.

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