b0,..,b3是贝塞尔,c-1, c2是catmull rom控制点
[b0] = 1 [ 0 6 0 0] [c_1] [b1] - [-1 6 1 0] [c0] [b2] 6 [ 0 1 6 -1] [c1] [b3] [ 0 0 6 0] [c2][b0] = 1
b0,..,b3是贝塞尔,c-1, c2是catmull rom控制点
[b0] = 1 [ 0 6 0 0] [c_1] [b1] - [-1 6 1 0] [c0] [b2] 6 [ 0 1 6 -1] [c1] [b3] [ 0 0 6 0] [c2][b0] = 1