How to tell if my character hit a collider of a certain layer

Questions & Answers
1

I’m making a little snowboarding game and I’m making a rail. I added a physics material to the character that makes him only able to go in one direction. I want to change the physics material when he comes into contact with a rail. I put the rail on a different layer, I just don’t know how to tell if the character collided with the rail or not.

2

Let’s assume you’re using OnCollisionEnter() to catch the collision. By using the Collision argument that’s passed in, you can read some information about the other object – for example, its layer:

function OnCollisionEnter(collision : Collision)
{
    Debug.Log(collision.collider.gameObject.layer);
}

You probably want to check if that object is on a particular layer, though:

function OnCollisionEnter(collision : Collision)
{
    if (collision.collider.gameObject.layer == LayerMask.NameToLayer("LAYER_NAME"))
    {
         Debug.Log("Touched a rail");
    }
}

Some script reference pages that might be helpful: