I have a scene with RBD objects (RBD solver engine: Bullet) moving downwards and colliding with particles on the way. I now want to delete these objects (or make them computationally cheap) as they move out of view at the bottom.

I looked at a few solutions here in the forum and elsewhere but they seem overkill for my needs and I have a hard time understanding them.

I'm wondering if I can assign objects to a Group based on the “Y” position of their centroid ("ty“ I think?) and apply a Delete node to that group further down the chain. Since more than one RBD object will need to be tagged by the Group node, do I need to apply some looping mechanism, or does the Group node cycle over all inputs, evaluation the expression in a ”generic" way for each?

I hope you got an idea of what I'm after, thanks.

Use “Active Value” DOP or “RBD Keyframe Active” which have more options.

here is example:

Delete based on position:

Thank you Pradeep, the example files are very instructional; I hadn't considered that the py value of the RBD object needs to be taken into account when checking object location. This was very helpful.