Limiting explosion

Unity Engine
1

So I’m trying to add an explosion to an object falling on the ground. I’m using Physics.OverlapSphere, but the problem is this adds explosion force to the ground as well, which then adds explosion force to everything on the ground. Is there a way to limit the explosion to just the falling object, and everything it hits, but not add it to the ground?
Here is the script I am using attached to the falling object, a.k.a. “Player.”

function Start () {
		// Applies an explosion force to all nearby rigidbodies
		var explosionPos : Vector3 = transform.position;
		var colliders : Collider[] = Physics.OverlapSphere (explosionPos, radius);
		
		for (var hit : Collider in colliders) {
			if (hit  hit.rigidbody)
				hit.rigidbody.AddExplosionForce(power, explosionPos, radius, 3.0);
		}
	}
2

You can use a Layermask with Physics.OverlapSphere, so what you could do is add all objects that should be influenced by your explosion to one layer, and create a Layermask that only affects that layer.
On the other hand, if you remove the rigidbody from your ground your code should already work, and in most cases it doesn’t need one.

3

I thought objects needed two sets of rigid bodies to detect collisions, both the Player and the collision object. Will it work with just one rigidbody?

4

Yes. Generally, if it doesn’t move then it shouldn’t have a Rigidbody. http://docs.unity3d.com/Documentation/Manual/Physics.html