vector primduv(string geometry, int prim_number, vector2 uv, int du, int dv)
geometry
A string specifying a geometry file (for example, a .bgeo
) to read from. When running inside Houdini, this can be an op:/path/to/sop
reference.
prim_number
The number of the primitive on which to measure the derivative.
uv
The parametric coordinates on the primitive at which to measure the derivative.
du
, dv
Represent the derivative order to query.
On a curve, the curve direction is given by du==1
and the curvature is given by du==2
.
This only works on NURBS and Bezier curve primitives.
du is currently ignored as it is meant to work with parametric surfaces.
See also | |
deriv | |
prim |
|