Select all geometry touching a user selected object?

#1

I’ve never scripted before. I have a complex scene with many objects and selection is difficult. I’m dreaming of a script that selects those objects that are touching a user-selected object. I’m thinking maybe getting the bounding box of the first object then somehow selecting those objects that intersect that bounding box ? Depending on the geometry those might not actually be physically in contact with the first. just very close. I can figure out filtering options later, but that first part : pick object --> get bounding box --> get all scene objects --> filter by intersection with bounding box of first, has me stumped.
Can anyone kindly make me smarter ?

Thanks!

#2

in general the task is not simple. but if we do only world-oriented (or called non-oriented) bounding boxes:

fn findBBoxIntersected node nodes: = 
(
	fn getNodeBBox3 node = 
	(
		bb = nodeGetBoundingBox node (matrix3 1)
		box3 bb[1] bb[2]
	)
	
	if nodes == unsupplied do nodes = objects 
	
	b = getNodeBBox3 node
	
	_nodes = for n in nodes where n != node collect
	(
		x = getNodeBBox3 n
		if intersects b x then n else dontCollect
	)
	
	_nodes
)

findBBoxIntersected $

The next in complexity:

  1. finding the intersection of oriented bounding boxes.
  2. finding by convex hulls (quick hull) intersection
  3. finding by the actual geometry (which may have different implementations: grid, voxels, kd-tree, Rtree, etc.)
#3

By the way… I remember at least 3–4 threads on this forum related to this task.