| 摘要 |
PURPOSE:To obtain unextended mapping to which a seal is stuck and expansible mapping to which a rubber film is stuck by utilizing lengths along a patch in case of mapping and displaying a texture on a parametric patch. CONSTITUTION:When lengths Lv (u0, u1, v), Lu (v0, v1, u) along the parameter coordinate system of the patch are directly used as indexes to the texture coordinate system, mapping can be attained without changing the length of the texture. The coordinate value (s, t) of the texture for a point P (u, v) on the patch is found out by the shown equations (provided that (a) to (d) are constants). Thereby, mapping can be attained without extending the texture in the direction along the parameter coordinate system of the patch. Then, the ratio of texture lengths along the patch on the points of the patch to the whole lengths along the (u) and (v) directions of the parameter coordinate system of the patch is found out. Since the coordinate value (s, t) of the texture corresponding to the point (u, v) on the patch can be found out, skewless mapping can be attained by using the color T (s, t) of the texture on that point. |
