Ignore 2D physics collisions

Questions & Answers
1

I am using Unity 5 and I want to detect collisions between my player and the floor but I do not want physics to stop the rigid body passing over the floor. How do I do this?

Basically I want my player object to know what type of floor it is on but I obviously still want to walk over the floor.

2

You could add a layer for each type of floor and test what layer the player’s collider is touching.

public LayerMask lava;
public LayerMask grass;

private CircleCollider2D feet;

void Start(){
  feet = GetComponent<CircleCollider2D>();
}

void Update(){
  if (feet.isTouchingLayers(lava))
    death...

  if (feet.isTouchingLayers(grass))
    that's ok
}