| 摘要 |
PROBLEM TO BE SOLVED: To decide a vertex normal vector easily and also with high accuracy by extracting what shares each vertex among original triangles, acquiring a normal vector as plural surface normal vectors about the plural original triangles that are extracted and deciding the vertex normal vector based on it. SOLUTION: When an object vertex does not exist on a feature line, one vertex normal vector 142 is decided as the weighted mean of all of surface normal vectors 132 to 140 of plural original triangles 122 to 130 which share the vertex 120. When the object vertex exists on the feature line, a 1st vertex normal vector 164 is decided as the weighted mean of three surface normal vectors of three original triangles 154 to 158 which belong to a 1st group about an object vertex 152 existing on a feature line 150. On the other hand, a 2nd vertex normal vector 166 is decided as the weighted mean of two surface normal vectors of two original triangles 160 and 162 which belong to a 2nd group. |
