Abstract:

To solve the problem of trimmed surface definition and trimming boundary alteration in B-spline surface trimming approach, a new T-Splines trimming approach was proposed and was used for the surface trimming upon multilateral rectangular domain. After converting B-spline surface into a full-row-column T-Splines, a trimmed T-Splines was obtained by applying the local uniform refinement and removing control points of T-Splines. The trimmed T-Splines was built upon a multilateral T-Mesh with a complete surface definition, and the trimming boundary can be locally modified. Finally, the trimmed T-Splines was proved to be superior to the trimmed B-spline surface in surface definition and boundary alteration with a modeling example.

Key words: B-spline surface, T-Splines, surface conversion, local uniform refinement, control point removement, surface trimming

摘要：

针对B样条曲面裁剪法中的裁剪曲面定义与裁剪边界修改问题，提出一种T样条曲面裁剪法，并用于多边矩形域上的曲面裁剪。先将B样条曲面转换为一张全行列T样条曲面，然后再利用T样条曲面的局部均匀细分和控制点移除，得到一张T样条裁剪曲面。裁剪后的T样条曲面建立在一个多边T网格上，具有完整的曲面定义，并且可以局部修改其裁剪边界。最后通过实例验证了T样条裁剪曲面在曲面定义和边界修改上都优于B样条裁剪曲面。

关键词: B样条曲面, T样条, 曲面转换, 局部均匀细分, 控制点移除, 曲面裁剪