bsplinecurve bspline_3d_np_c_r 2 3 0 3 1 1 2 3  0 0 0 2  1 1 1 1  1 0 0 1  0 0 0 2
extsurf es_bspline_3d_np_c_r  bspline_3d_np_c_r 0 0 1
trim es_bspline_3d_np_c_r_tr es_bspline_3d_np_c_r 0 1 0 1
trim es_bspline_3d_np_c_r_tr_tr es_bspline_3d_np_c_r_tr 0 .5 0 .5
mkface result es_bspline_3d_np_c_r_tr_tr 0 .25 0 .25
set MaxFTol 9.9999999999999995e-08
set MaxETol 9.9999999999999995e-08
set MaxVTol 9.9999999999999995e-08