Compact Car-Body Surface Design with T-spline Surface

Creating proper B-spline surface models is a very challenging task for designers in car-body surface design. Due to the tensor-product structure of B-spline surface, some undesirable issues of the redundant control points addition, incomplete surface definition and the difficulty of trimming boundary alteration frequently occur, when designing the car-body surface with B-spline surfaces in local-feature-lines construction, full-boundary-merging and visual surface trimming. A more efficient approach is proposed to design the car-body surface by replacing B-spline surface with classical T-spline surface. With the local refinability and multilateral definition offered by T- spline surface, those designing issues related with B-spline surface can be overcomed. Finally, modeling examples of the door, hood and rear-window are given to demonstrate the advantage of T-spline surface over B-spline surface in car-body surface design.     

基于队列的参数域T网格Bézier分割方法

针对T样条曲面Bézier提取中的参数域T网格的Bézier分片问题,提出了一种基于队列的参数域T网格的Bézier分片算法。该算法首先通过延伸T型参数点对参数域网格进行切分,之后通过计算每个参数点所耦合的T样条混合函数非零区域对参数域网格进一步切分。上述切分过程只需借助一个队列数组即可实现。通过实例测试,验证了本算法的有效性。