The Surfsect SOP performs boolean operations with NURBS and Bezier surfaces, or only generates profiles where the surfaces intersect. The individual surfaces do not need to be solids (i.e. wrap in U and V), nor do they need to form a solid as a group (for example, you can cut a grid with a sphere).
The surfaces in the first input are denoted by "A" in the parameter list. The surfaces in the second input are denoted by "B". The entire A set is intersected with the B set, which allows for true csg operations with spline surfaces. Thus, if A forms a solid and B forms a solid, any boolean operation between A and B will produce a solid. If either set has an open topology, the result will also be open.
What is deemed to be the inside and outside of a trim region depends on the direction of the surface normals. If necessary, use the Primitive SOP to reverse the surface normals by reversing the surface's U or V direction.
/groupa - Subset of NURBS and Bezier surfaces. Accepts patterns, as described in Pattern Matching.
/groupb - Subset of NURBS and Bezier surfaces to intersect with A. Accepts patterns, as described in Pattern Matching.
/tol3d - World space precision of the intersection.
/tol2d - Domain precision of the intersection.
/step - Number of steps for tracing each profile span.
Enables boolean operations between the surfaces in A and B:
/boolop - Select from the following operations: Union, Intersect, A-B, B-A, or User-defined.
If the Operation is set to User-defined, the following options become available:
- Keep Inside A
/insideA- Preserve the inside sections of the A surfaces.
- Keep Inside B
/insideB- Preserve the inside sections of the B surfaces.
- Keep Outside A
/outsideA- Preserve the outside sections of the A surfaces.
- Keep Outside B
/outsideB- Preserve the outside sections of the B surfaces.
Just create profiles where the surfaces intersect.
/target - Which surface to output profiles for: A, B, or both.
A Profiles Group
/Aprofiles - Place the A profiles in a user-defined group.
B Profiles Group
/Bprofiles - Place the B profiles in a user-defined group.
Avoid Already Trimmed-Out Parts
/mindholes - Intersect only the visible surface parts and truncate the intersection profile at the trimmed-in surface boundaries.
Join Profiles Created By Multiple Surfaces
/join - If a surface has several adjacent profiles caused by its intersection with two or more surfaces, the profiles will be joined into a single curve-on-surface.