place an object on another object

[XxpiingyxX]

I have a box and I want to place an object (instanced mesh) randomly on that box, but its not allowed to be placed inside the box, only on the “outline”.
First I thought that I would create another box that’s just a tiny bit smaller than the original box, and then get the value between those two boxes and randomly place the new object there.
But I realized that I don’t know what nodes to use and/or what to search for.

Any help? Is there a better and/or easier way to do this?

[ClockworkOcean]

If you use a line trace, you can get the impact point and normal

[XxpiingyxX]

Will this work in a construction script?

[ClockworkOcean]

Yes, but I don’t quite get your concept.

Do you mean randomly place little cubes on a big one, for instance?

[XxpiingyxX]

Yes exactly.
(Like how BlenderGuru shows how to place sprinkles on a dount in blender with geometry nodes)

[Everynone]

• you could line trace from the outside towards the box (from the top)
• you could sweep - overkill for boxes but may be needed for irregular shapes
• you could math it out with component bounds:

50% chance to place a box on top

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to place sprinkles on a dount

Line trace, get normal and use components bounds to shift the sprinkle along the normal.

[ClockworkOcean]

[XxpiingyxX]

Thank you! This works, but If i have another object close to the big box it will add small boxes to that too

[ClockworkOcean]

Yes, it will

You could add the other object to the ‘ignore list’

Or you could use custom collision channels to avoid it

Unreal Engine 4 - Quick! How to: Use collision Channels - Pt. 2: Custom Collision Channels