Tomas Slancik

s@collisiongroup + s@collisionignore is the correct workflow, which is also part of CollisionIgnore recipe for Vellum Solver SOP

i@disableself + i@disableexternal work on per DOP object basis and since the whole geometry from the 1st input of Vellum Solver SOP is a single DOP object, there is no distinction between named pieces as far as "self" is concerned
So you can either do pure DOP setup where your pieces are separate DOP objects (Vellum Object DOP) or specify collisiongroup/ignore patterns to define relationships you want within a single object

olivierth
The windingnumber function looks nice but I don't have it in my H19.5 sadly.

you can also use Winding Number SOP instead, that is already present in 19.5

it's not clear to me whether you want to group all the points within any of the spheres, or just within the intersection of all spheres etc

but regardless, for arbitrary geo you can use windingnumber() VEX function to check whether the point is within the geo and how deep in case the geo contains intersections


for just spheres I agree that it's better to either use points with pscale or sphere primitives and iterate over them in for loop in VEX
or depending on number of points and colliders you can also use pcfindradius() if things get heavy,