RESEARCH ON ADAPTIVE DATA COMPRESSION METHOD FOR TRIANGULATED SURFACES

摘要

NC code or STL file can be generated directly from measuring data in a fast reverse-engineering mode. Compressing the massive data from laser scanner is the key of the new mode. An adaptive compression method based on triangulated-surfaces model is put forward. Normal-vector angles between triangles are computed to find prime vertices for removal. Ring data structure is adopted to save massive data effectively. It allows the efficient retrieval of all neighboring vertices and triangles of a given vertices. To avoid long and thin triangles, a new re-triangulation approach based on normalized minimum-vertex-distance is proposed, in which the vertex distance and interior angle of triangle are considered. Results indicate that the compression method has high efficiency and can get reliable precision. The method can be applied in fast reverse engineering to acquire an optimal subset of the original massive data.