I’m trying to decide how to approach object collision…
The situation are crowds of moving objects… even though their movements are 3D, it could be reduced to 2D (such as moving over a heightmap terrain)…
It is accetable that in my game collision with a tree, for instance, could be represented as a sphere or even a radius. (it will generally be top down)
So! Which do you think would be more efficient?
Simply doing a radius check with a tree and the current position of an object to see if it’s too close to the tree?
Raycast along the current move direction into a Sphere Collider on the tree?
Or use Sphere colliders on everything? (I assume this would let PhysX handle the load? But is that faster?)
If my explanation is abit ambiguous let me know! 
Thanks!