Liu Weijun

A Robust and Topological Correct Marching Cube Algorithm Without Look-Up Table

In this paper, we proposed an improved version of the marching cube algorithm which gives a topologically correct triangular approximation of the isosurface for any cube configuration. First, a classification and characterization of critical points on the isosurface of trilinear functions is studied in detail. Then, unlike the past work on marching cube algorithm, a robust triangulation strategy without using the conventional look-up table and complementary and rotation operations is presented. Our algorithm is adaptive to the small changes of the data or the small changes of the threshold, and obtains more reasonable result of triangulation of isosurface than those produced by standard MC algorithm

New kind of subarea-parallel scanning mode for laser metal deposition shaping

A scanning mode is the key technology in a laser metal deposition shaping (LMDS) fabrication process. On the basis of the analysis of existing scanning modes and their influences on the fabrication efficiency and the quality of parts, some disadvantages of them are pointed out. A new kind of subarea-parallel scanning mode for LMDS based on a subdividing profiled outline into monotonous polygon subareas is presented. First, based on the principle of point visibility, inner loops are eliminated, and simple polygons are subdivided into monotonous polygons with the minimal zones. Second, the parallel scanning paths of all monotonous polygon subareas are finished, which diminishes the length of the scanning line. The practical application shows that the scanning mode can enhance the fabrication efficiency and quality.