Collision position

Unity Engine
1

Hey guys,

I’m trying to work out a reaction force for collisions, and I figured the best way to do this would be to just look at the position-vector of the collision, and the position-vector of the centre of the player, and then say that a force is applied in the direction of the vector between those two.

However, I have no idea how to find out the position of where the collision takes place? I mean, Unity must calculate it to realise one polygon has hit another polygon… I want to know the position of the two polygons that are hitting. Is this possible?

Thanks if anyone can help me out here.
Stephen

2
3

Hey, thanks - I don’t know why I couldn’t find that page to start with :expressionless:

But now I’m stuck using the code, I’ve put it in but it doesn’t seem to activate itself,

function OnCollisionEnter(collision : Collision){
	var shipHandleScript:shipHandleScript = transform.parent.parent.GetComponent("shipHandleScript");
	for(var contact:ContactPoint in collision.contacts){
		Debug.Log(1);
		shipHandleScript.shipForce -= shipHandleScript.shipVelocity.magnitude * Vector3.Normalize(transform.position - contact.point) * Time.deltaTime * 50000;
	}
}

I’ve got that in, but it does nothing when the transform collides with something else. (I know the collision is valid because my code from an OnTriggerEnter runs just fine)

4

Is there a rigidbody on the object with the script? You can switch on its Is Kinematic option if you don’t want the object to have physics.

5

Hey, yeah there is a Rigidbody attached to the object with the script. I can’t work out what’s wrong :expressionless:

6

Maybe my structure with the rigidbody and colliders etc. is wrong? I have…

Ship ← (Contains OnCollisionEnter script)
-Colliders
–ColliderMain ← (Contains rigidbody and collider)

Building
-Colliders
–ColliderMain ← (Contains collider)

Does this seem right?