Create or edit profile (trim) curves
Houdini supports curves on surfaces (also known as trim curves and profile curves). Profile curves are 2D curves that exist in the parametric (UV) space of their parent surface. Houdini draws profile curves as dotted lines on the surface.
|Create a profile curve on a surface|
|Trim a NURBS surface with a profile curve|
|Extract a profile curve to a 3D curve|
|Transform a profile curve|
|Delete a profile curve|
Houdini has polygonal, NURBS, and Bezier profile curves. Each profile curve type is very similar to its 3D equivalent. For example, a NURBS profile can be open or closed, clamped or un-clamped, rational or non-rational, with order between 2 and 11.
The entire profile or part of it can move outside the surface boundaries, and become clipped at the surface edge. A profile curve that is partially or completely clipped is still valid and can be moved back onto the surface. See the Profile and Primitive sops for ways to manipulate a profile.
You can check whether a node’s geometry has invisible profile curves by pressing on the node tile. The pop-up info window shows the number of visible and hidden profile curves in the geometry.
A profile can co-exist with 3D primitives in primitive groups. A resulting mixed group would specify its elements like this:
1 0.2 6 2.9-2.17 4.*.