Trims away parts of a spline surface defined by a profile curve or untrims previous trims.
With the Trim op you can cut out parts of a spline surface, or uncut previously cut pieces. When a portion of the surface is trimmed, it is not actually removed from the surface; instead, that part is made invisible. This means that you can still modify the surface (modify the position of its points, for instance) that is not displayed in order to affect the part that is displayed.
The surface can be trimmed by specifying open or closed profiles as inside or outside regions. The profiles need not be contained within the domain (UV space) of the surface; they can also be nested.
Open profiles are treated as follows: if both ends of the profile are inside the surface, the ends are connected to one another; if the profile’s ends are outside the domain of the surface they are projected onto, that part of the surface appears to be cut away.
Use a Trim SOP to cut a hole in the projected surface.
Use a Bridge SOP to skin the profile curve to another profile curve.
Use a Profile SOP to extract the curve on surface or remap it’s position.
Selection Method: Winding Rule
The selection method employed for clarifying overlapping trim loops is the winding rule, which executes overlapping commands instead of having them cancel each other out.
The following results were obtained by using a Project SOP to project two NURBS circles onto a NURBS grid. Then two Trim SOPs were added, one after the other, to the Project SOP. The first Trim SOP was set to Keep Inside, while the second Trim SOP had its operation changed as indicated.
The illustrations show a Gouraud shaded view of the resulting geometry.
Subset of profiles to use as trim curves.
Lists the types of trimming operations available:
|Process profiles individually|
Generate a trim region out of of each profile or treat the whole group as one.
|Build outer-trim loop explicitly|
Generate a trim loop around the surface boundary. One is created automatically when a surface is trimmed for the first time if “Keep Outside” is on.
How close two trim curves must be to each other or to the edge of the patch to be considered an intersection.
The new altitude for the surface.