Detecting where a collision came from?

Unity Engine
1

How can I detect what direction a collision has occurred from?
When an enemy or a projectile collides with my player, I need to know what side the player was hit from. I am working in 2D, so I don’t need to know more than if it came from the left or right side, that is, positive or negative x.

I’m reading through the documentation, and collisions carry a “contacts” element that has information about where the collision occurred. But I can’t find how to access it.

The documentation just says:

So I looked up ContactPoint2D, and it has variable called point, which is a vector2 with the location in world.
But I don’t know how to retrieve this data.
I’ve tried

	void OnCollisionEnter2D (Collision2D col)
	{
		//col.contacts.point.x
		//col.contacts.x
		//col.contacts.ContactPoint2D.point.x
		}

but none of those return as something that contacts has a definition for. The documentation does not explain to me what I can get from the contacts.

My plan is to compare that collision point to the player’s location, like this:

if ( (world location of collision in x) < col.gameObject.transform.position.x)
				Debug.Log("Hit from Left");

which I believe will work, but I don’t know how to retrieve that collision location properly.

2

The contacts are an array, so you will need to access them as such.

col.contacts[0].point.x
3

Oh. Why are they an array? If multiple objects collide with this object, won’t each one call its own OnCollisionEnter? Won’t each individual object create its own collision?

4

Im having the same issue. I am trying to access the collision point.

Did you find a solution?