DESCRIPTION:

Remark classes on the NURB, near the NURB surface or
inside the NURB, depending on the dimension of the NURB.
For 1-dimensional NURBs, lines will be drawn in the volume
that will approximate the NURB.
For 2D NURBs, the extra parameters zstart zend need to be
specified. In this case, the command will remark a thick
surface starting at the NURB surface plus zstart times the
NURB normal, and ending at surface plus zend times the normal.
3D NURBs will be filled by drawing cuboid regions just like
the grid used to visualize the NURB.
Using options, this behaviour can be changed, so that 2D and
3D nurbs can also only plot lines or surfaces. The following
options apply:
-l : draw lines only, even if 2D or 3D
-s : draw surfaces only, even if 3D
-i : draw inner lines or surfaces
In the 2D case only the border is drawn, if -l is set unless -i
is set as well.
In the 3D case only the outer surfaces will be used for drawing
lines or surfaces unless -i is set.