| 摘要 |
PURPOSE:To improve the dimensional accuracy of a photo-shaped matter by a method wherein a polygonal patch locating at the base of a shaped matter is judged by the positive or negative Z-component of a normal vector after the apices are rearranged and rewritten in nodes and finally correction is performed to the Z-distance of the node of a negative patch. CONSTITUTION:By specifying a surface shape data file, the apex coordinates of a patch and normal vectors are read and the total number of patches are counted. Next, node numbers are given to apex coordinates so as to memorize which nodes compose respective patches. Further, in order to detect overhanging, positive or negative Z-distance of normal vector is checked so as to be up a flag to a node constituting a negative patch. The above-mentioned procedure is repeated on all the patches. Next, all the nodes are checked so as to set the amounts of correction to the nodes, in which the flag is up, in order to add the amount of correction to the Z-distance of the node and to be rearranged as the new values of the coordinates, apex coordinates consisting of patches are rewritten. In this case, the normal vector of the patch is calculated with the corrected Z-distance. |
