Two kinds of extensions of bicubic Coons patch
双三次Coons曲面片的两种扩展*

The shape of traditional bicubic Coons patch would be hard to adjust when the boundary conditions are given. For solving this problem,this paper presented a class of Hermite basis functions with a shape parameter firstly. And established a kind of Coons patch with two shape parameters used the proposed basis functions , named QC-Coons patch.Then, constructed a kind of rational Coons patch with two shape parameters by reparametering the proposed basis functions,named RQC-Coons patch. Results show that the two generated patches are extensions of bicubic Coons patch, they not only inherit the most properties of double cubic Coons patch, but also can show different interior shapes by changing the values of shape parameters. The generated patches offer two new methods for designing the Coons patches.