pbsplinecurve bspline_3d_p_nr 2 4 0 1 1 1 2 1 3 1  0 0 0 1  1 2 0 1  2 0 0 1
extsurf es_bspline_3d_p_nr  bspline_3d_p_nr 0 0 1
trim es_bspline_3d_p_nr_tr es_bspline_3d_p_nr 0 1 0 1
mkface result es_bspline_3d_p_nr_tr 0 .5 0 .5
set MaxFTol 9.9999999999999995e-08
set MaxETol 9.9999999999999995e-08
set MaxVTol 9.9999999999999995e-08