中介曲面法处理G^2兼容性约束条件

Handling of G^2 Compatibility Constraint Conditions Using intermediary Surface Method

提出一种曲面拼接中分离二阶几何连续兼容性约束的新方法．与直接解约束方程的方法不同，这里使顶点周围曲面片的法向投影与顶点处某一中介曲面具有若干阶逼近，就能分离法向约束，再通过拼接函数的端点值及端点导数的选取使约束的切平面投影得到满足．

A new method, the intermediary surface method, to separate the G2 compatibility constraint conditions at the composite surface vertex is presented. Unlike the method of solving the constraint equations directly, the Intermediary surface method makes the normal projections of the surface slices surrounding the vertex have certain order of approximation to an intermediary surface at the vertex. The constraints in normal direction can then be separated, and the constraints in the tangent plane can be satisfied by proper selection of the end-point values and end-point derivatives of the composite functions.