NURDSes Non-uniform Recursive Doo-Sabin Surfaces Quad case P P3 P Q0= p0p1p2P3+90919293 +q1p1P2p3+9192P2P3+q1q293P3 a1= PopiP2P3+90919293+PPo+9243P3Po+q2939oPo 2 PoP1P2P3+90919293 +q3p3pop1 +9390PoP1+939091P1 3= P0p1P2P3+90919293 +90p0p1p2+9091P1P2+90q1q2P2 ZHuang.G Wang Non-Uniform Recursive Doo-Sabin Surfaces (NURDSes) NURDSes Non-uniform Recursive Doo-Sabin Surfaces Quad case α0 = p0p1p2p3 + q0q1q2q3 2 + q1p1p2p3 + q1q2p2p3 + q1q2q3p3 α1 = p0p1p2p3 + q0q1q2q3 2 + q2p2p3p0 + q2q3p3p0 + q2q3q0p0 α2 = p0p1p2p3 + q0q1q2q3 2 + q3p3p0p1 + q3q0p0p1 + q3q0q1p1 α3 = p0p1p2p3 + q0q1q2q3 2 + q0p0p1p2 + q0q1p1p2 + q0q1q2p2 Z Huang, G Wang Non-Uniform Recursive Doo-Sabin Surfaces (NURDSes)