Unpacking only the instances that cross partially into a volume

[Honokaitj]

I'm having trouble figuring out the best way to achieve something.  I'm creating a wall of bricks.  Each brick will later be replaced by a far more detailed brick.  I'm trying to keep my scene as light and memory efficient as possible so I'm using copy to points and pack and instance is checked.  However, I need to cut a hole into this wall.  In my example it is a tube, but I'd like to figure out how to do this with any shape.  What I want to do is figure out how to do one of two things.

1. Prior to copy to points create a group of the points which will later have bricks that need unpacked in order to boolean.

2. After copy to points with pack and instance create a group of packed bricks that will need to be unpacked in order to do a boolean.  

If you look at the image I've provided you'll see some points are outside of the tube shape, but would still need to be part of the group that gets/remains unpacked.  At the same time some are mostly or completely inside the tube and would also need to be unpacked.  I know I can just use a peak node on my tube to make it wider just for selecting, but I'm wondering if there is a more elegant way of doing this.  I was thinking of something like intersection analysis, but that isn't the right thing.  Is there a way to determine if a packed/instanced brick is partially inside the tube geo?

Thanks,

Tim J

[Skybar]

Hey! You could compare the bounding boxes, and unpack only those that overlap. Here are 2 similar methods for that Hope it helps!

unpackbbox_dv.hip

[Honokaitj]

Thank you!  It's cool to see how other people solve problems.  Thanks for the example file!