Mesh Brep Intersection

I’m trying to return the mesh faces that fall within a surface boundary. Essentially like a Mesh | Brep intersection or Mesh | Surface. Can anyone help?

Flat surface?, Spherical surface?, Cylindric surface? Box surface? What kind of surface?

Whatever surface you want to use for selecting faces, you can deconstruct mesh faces and test if the face center point (rough test) is on the desired side, or all corners (rigid test).

You can also test for (poly)line intersections (using the lowest component in picture) if you want faces which intersect any brep-faces, etc.

Once you extracted the surface points (centers or corners) you can use PointInBrep etc. if you keep track of the indices so you then can select the corresponding faces by index from the DeconstructMesh->Faces output.

// Rolf

Hi Rolf - I really thought the logic of testing face normal centers within the surface would work but it’s returning all false values.

I basically have a 1 m^2 rectangular boundary that can move to different areas of the 2D mesh wall. I’m hoping find which faces are within that boundary so I can cull the original list & return a mesh of only the included faces.

It looks like you have open surfaces, then there’s no “within”. If you cast the Surface to a Plane you can test whether a MeshFace center is “below” or “above” the Plane.

I might not understand the problem based on that picture (can’t see what you have tried). Better to post a simplified file with only the relevant parts so someone can help.

// Rolf