Offset of STL Model Generated from Solid Model

솔리드 STL 모델의 옵셋 방법

  • 김수진 (한국과학기술원 기계공학과) ;
  • 양민양 (한국과학기술원 기계공학과)
  • Published : 2005.09.01


This paper introduces and illustrates the results of a new method fer offsetting triangular mesh by moving all vertices along the multiple normal vectors of a vertex. The multiple normal vectors of a vertex are set the same as the normal vectors of the faces surrounding the vertex, while the two vectors with the smallest difference are joined repeatedly until the difference is smaller than allowance. Offsetting with the multiple normal vectors of a vertex does not create a gap or overlap at the smooth edges, thereby making the mesh size uniform and the computation time short. In addition, this offsetting method is accurate at the sharp edges because the vertices are moved to the normal directions of faces and joined by the blend surface. The method is also useful for rapid prototyping and tool path generation if the triangular mesh is tessellated part of the solid models with curved surfaces and sharp edges. The suggested method and previous methods are implemented on a PC using C++ and illustrated using an OpenGL library.



  1. Choi, B. K., Kim, D. H. and Jerad, R. B., 'C-Space approach to tool path generation for die and mold machining,' Computer-Aided Design, Vol. 29, No.3, pp.657-669, 1997
  2. Cho, S. H., Cho M. W. and Kim, J. D., 'Reverse Engineering of 3D Compound Shapes using Delaunay Triangulation,' Journal of the Korean Society of Precision Engineering, Vol. 17, No.7, pp. 181-188, 2000
  3. Lee, S. H., Ahn, D. G. and Yang, D. Y., 'Surface Recosntruction for Cutting Path Generation on VLM-Slicer,' Journal of the Korean Society of Precision Engineering, Vol. 19, No. 7, pp. 71-79, 2002
  4. Jun, C. S., Kim, D. S. and Park, S. H., 'A new curve-based approach to triangle machining,' Computer-Aided Design, Vol. 34, No.5, pp. 379-389, 2002
  5. Koc, B. and Lee, Y. S., 'Non-uniform offsetting and hollowing objects by using biarcs fitting for rapid prototyping process,' Computers in Industry, Vol. 47, pp. 1-23, 2002
  6. Qu, X. and Stucker, B., 'A 3D surface offset method for STL-format models,' Rapid prototyping journal, Vol. 9, No.3, pp. 133-141, 2003