Returns the length of the 3D curve between two points on a surface.
surflen(surface_node, prim_num, ustart, vstart, ustop,
Given a surface and two parametric points in its domain (
[ustop,vstop] ), surflen computes the length of the
3D curve that stretches between the two points. This curve is the 3D
image of the line in the surface domain, whose end-points are
[ustop,vstop]. If either u or v is kept constant,
the 3D curve coincides with an isoparm.
All four uv numbers are unit values, defined in the
the primitive must be either a NURBS surface or a Bezier surface. A polygonal mesh can be simulated by a bi-linear Bezier surface (u and v order 2).
surflen("/obj/geo1/grid1", 12, 0, 1, 0.2, 0.8)
Computes the length of the curve on surface #12, defined
parametrically by the surface domain points