# Geometry Nodes - Instancing from Collections

Using 3.0.0 Beta, it looks like Instance on Points replaces the *Point InstanceU node, but using this with collections is stumping me.

I'd like random instances from a collection to be used at each point in some geometry. I see how to use *Collection Info and Pick Instance nodes. But the Instance Index confuses me; is there a way to get the size of a collection and use that to randomize selection? I happen to know my collection has 2 instances and I set the Random Value node accordingly, but I'd like a more general way to do this.

Here is a node tree that I created:

Is there a way to get the size of a collection?

• if you set the max. Random Value to a large number, as far as I can see, it is taken to be Modulo(Number of Children) , so a near-as-doesn't-matter random selection can be made per-point. Is that good enough? Nov 6, 2021 at 19:13
• This is good enough, and you are correct. I went looking into the sources and found where it does use the modulo of the index, and it looks like my idea of the "size" of the collection may be too simplistic. It seems, with your suggestion I should make both the min and max random values higher than the size of the collection; if the random number is smaller than the collection size, the higher indices would be unselectable. Nov 7, 2021 at 12:58