bsplinecurve bspline_3d_np_c_nr 2 3 0 3 1 1 2 3  0 0 0 1  1 1 1 1  1 0 0 1  0 0 0 1
extsurf es_bspline_3d_np_c_nr  bspline_3d_np_c_nr 0 0 1
trim es_bspline_3d_np_c_nr_tr es_bspline_3d_np_c_nr 0 1 0 1
trim es_bspline_3d_np_c_nr_tr_tr es_bspline_3d_np_c_nr_tr 0 .5 0 .5
mkface result es_bspline_3d_np_c_nr_tr_tr 0 .25 0 .25
set MaxFTol 9.9999999999999995e-08
set MaxETol 9.9999999999999995e-08
set MaxVTol 9.9999999999999995e-08