Doo-Sabin Subdivision n-1 p=>wP,i=0,n-1. j=0 Doo-Sabin version [Doo and Sabin 1978],extended to quadratic NURSS: i=j 3+2cos(2m-1/D,i≠j 4n Catmull-Clark variant [Catmull and Clark 1978]: 是+动，i-引=0 +,i-引=1 i-引>1 Z Huang.G Wang Non-Uniform Recursive Doo-Sabin Surfaces (NURDSes)Doo-Sabin Subdivision Pi = Xn−1 j=0 wijPj , i = 0, . . . , n − 1. Doo-Sabin version [Doo and Sabin 1978], extended to quadratic NURSS: wij = ( n+5 4n , i = j 3+2 cos(2π(i−j)/n) 4n , i 6= j Catmull-Clark variant [Catmull and Clark 1978]: wij =    1 2 + 1 4n , |i − j| = 0 1 8 + 1 4n , |i − j| = 1 1 4n , |i − j| > 1 Z Huang, G Wang Non-Uniform Recursive Doo-Sabin Surfaces (NURDSes)