Fast slicing algorithm of STL model

Abstract

A fast slicing algorithm for the STL model. According to the geometric information and slice thickness of the triangular patches in the STL model, the triangular patches are grouped and sorted to reduce the number of triangular patch traversals; by constructing the local dynamics between the triangular patches The triangle surface table reduces the number of intersection calculations between the slice plane and the triangle surface; and according to the topological relationship of most triangle surfaces in the slicing process, an algorithm for updating the dynamic triangle surface table is proposed, which reduces the time required for The number of search times for the adjacency relationship of the triangular facets, thus improving the overall efficiency of the slicing algorithm. The topology reconstruction and slicing work of the STL model can be quickly completed by updating the algorithm. From the time complexity analysis: in the best case, that is, no new triangular patches are added to the i+1th layer, so there is no need to perform triangular patches For topology reconstruction, the time required is only to calculate the contour ring of the current layer according to the topological relationship; so a lot of time is saved.

Description

[0001] 1. Technical field [0002] STL model files are standard files in 3D printing systems. The algorithm of the invention is applicable to the 3D printing industry, further promotes the development of the 3D printing technology, not only improves the precision of the processed model, but also shortens the processing time of the model. [0003] 2. Background technology [0004] The essence of 3D printing lies in layered manufacturing, so in the design of rapid prototyping software system, slicing processing is one of the key contents. The traditional slicing algorithm generally uses equal layer thickness, which will cause a gap between model accuracy and printing time. Contradiction: The thickness of the layer is small, the accuracy of the model is guaranteed, but the printing time is relatively long; on the contrary, the printing time is shortened, but the accuracy of the model is not high and the model step error is relatively large. In the field of mechanical rapid protot...

AI Technical Summary

Problems solved by technology

[0004] The essence of 3D printing lies in layered manufacturing, so in the design of rapid prototyping software system, slicing processing is one of the key contents. The traditional slicing algorithm generally uses equal layer thickness, which will cause a gap between model accuracy and printing time. Contradiction: The thickness of the layer is small, the accuracy of the model is guaranteed, but the printing time is relatively long; on the contrary, the printing time is shortened, but the accuracy of the model is not high and the model step error is relatively large

The commonly used method of the STL layered slicing algorithm is: by analyzing the positional relationship between the tangent plane and the triangular mesh, if the tangent plane intersects with the triangular mesh, find the intersection line segment, and find all the relationship between the tangent plane and the STL mesh model. After the intersecting line segments, all the intersecting line segments of the layered layer are connected in an orderly manner to obtain the contour line of the layered slice surface. When obtaining the contour line by this method, it is necessary to ensure that all triangular mesh faces are traversed. However, when calculating the contour line, most of the patches may not intersect with the tangent plane, which results in low data processing efficiency and a relatively large amount of calculation. In order to improve the layering efficiency, many researchers at home and abroad are conducting research and proposed Some layering algorithms are proposed, first of all, the original STL model data is preprocessed, and then layered slices are performed. Through analysis, it is found that the main slice layering algorithms can be divided into the following three categories: layered slice algorithm based on geometric topology information , the layered slicing algorithm based on the position information of the triangle patch, the layered slicing algorithm based on the geometric continuity of the STL mesh model, but the best slicing engine in the world is not good at this point, so for This layering technology still has a lot of room for development and optimization for the existing slice layering algorithm, and there are still many problems in the current layering software, and the forming accuracy and speed of the layering software are not the same. The errors caused by the conversion of CAD models into STL format files and subsequent slicing processing will affect the final molding accuracy of the model, and because there are many algorithms for model layering, different algorithms are used, and the speed of model layering is also different. Even the difference is dozens of times. The RP software on the market is not compatible with each other. It is very difficult to exchange data between different RP systems. Therefore, it is necessary to establish a common layered algorithm system.

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