What is the simplest way in houdini to check if a Point is inside a Mesh. Think of a Fluid-Mesh and i have somewhere else a scattered points, i want to group the scattered points which are drown by the fluid-mesh.

thanks!

I realized that the Group-Sop can have it's second input as a “bounding object”, as the delete node looked the same in terms of “Bounding Volume” i didn't think, that the Group-Node supports custom bounding objects.

thanks.

The group SOP will work, but it's slow for heavier bounding meshes.

If you specifically want to track whether particles are inside a fluid sim mesh, then you should store the surface VDB you use to create the mesh in the first place. Then you can just sample its value at any point to test whether that point is inside or outside of the surface.

Even if you're not testing a fluid mesh, it may ultimately be faster to use VDB from Polygons and then use that to test for inclusion.