Hi!

Let's say I have a mesh sphere that's half inside a bounding box in a group node. Is there any way I can procedurally “grow” the selection to add all the rest of the connected primitives to that sphere?

Do you want to expand your selection to the immediate connected prims?

If so, create a point group, and then promote it to primitives with the group promote node(be sure to have UNchecked the include only elementes entirely contained in original group). The new group will now include immediate connected prims.
Repeat this in a for loop to expand furthermore.

This is the same idea of the group expand node of the GameDev toolset.

Thanks for fast feedback!

I tried, but the result isn't what I was looking for. I would like to have all the primitives that makes up the selected spheres like in this example: link [www.dropbox.com]

oh now I understand, have a look at the attached file

not super efficient I must say, but it should works

Smart solution! Really cool of you to make this example, thanks a lot!