快速原型製造中STL 三角網格縮減之研究

STL Triangular Mesh Reduction for Rapid Prototyping Manufacturing

本文針對快速原型製造所支援的STL 三角網格檔進行縮減研究。網格縮減程序包括網格刪除與網格重建兩部分，在網格刪除上，係藉由建立的個數比例、差值比例權重比法則來執行刪除，網格經過刪除後，再以基因演算法則為基礎，建立一套修正型適應函數來重建網格，以建立STL 三角網格數量的縮減與形狀最佳化目標。研究上，並以兩個實例進行探討，達成對不同產品模型STL 網格的驗證，並以原始STL 曲面與縮減重建後的STL 網格進行表面輪廓誤差比對，以說明經由本研究所得的STL 縮減網格圖形檔與原始STL 曲面相較，可達到令人滿意的結果。本研究成果可實際應用於現行所有快速原型機台製造，藉由STL 三角網格之縮減法則，可具體完成模型所要求之表面輪廓精度與縮短製造成型時間。

The purpose of this paper is STL triangular mesh reduction in theprocess of rapid prototype manufacturing. STL mesh reduction includesmesh deletion and mesh reconstruction. This paper shows how to simplifythe STL mesh in the rapid prototyping process. Mesh deletion and a geneticalgorithm for the reconstruction of the mesh are two methods for gettingthe optimized STL file. Based on the portion of the amount of STL meshesor the differential values in deviation, a weighting factor is set for the meshdeletion. A modified fitness function of the genetic algorithm is used forthe mesh reconstruction. Two examples are given to examine STL filesimplification. By comparison with the original STL surface meshes, thesurface errors for the reconstructed STL meshes can be checked. A goodresult can be achieved for STL file reduction and optimized meshregeneration. The results of this research can be used for the RP process. Italso fits the surface clearance requirements and reduces the RP fabricationtime for building models.