Check if colliding with a layer

Questions & Answers
1

I want 2 if statements to check if and if not colliding with a layer called ground for jumping in my 2d platformer. I tried to copy from the unity 2d platformer tutorial but that doesn’t seem to be working, any tips on how to check if colliding with a layer called ground

public void Jump(){
		Debug.Log ("jump has also been called");
		if (grounded) {
			GetComponent<Rigidbody2D> ().velocity = Jumpforce;
			Debug.Log("grounded is true");
2

public bool isGrounded;
void OnCollisionEnter(Collision collision)
{
if (collision.gameObject.layer == 8 //check the int value in layer manager(User Defined starts at 8)
&& !isGrounded){
isGrounded = true;
}
}
void OnCollisionExit(Collision collision)
{
if (collision.gameObject.layer == 8
&& isGrounded){
isGrounded = false;
}
}

3

Using the bitwise operator you can able to find collisions with a layer mask.

        public LayerMask layerMask;
        private void OnTriggerEnter(Collider other) {
            if ((layerMask.value & (1 << other.transform.gameObject.layer)) > 0) {
                Debug.Log("Hit with Layermask");
            }
            else {
                Debug.Log("Not in Layermask");
            }
        }
4

Years later I am trying this and I can’t seem to get a collision based on layers to work.

Does anyone know why neither of these scripts would call the event or even show a debug log?
using UnityEngine;
using UnityEngine.Events;

public class LayerNumExample : MonoBehaviour
{
    [Tooltip("check the int value in layer manager(User Defined starts at 8)")]
    public int layerNumber = 8;
    public UnityEvent layerEnterCollision;
    public UnityEvent layerExitCollision;

 void OnCollisionEnter(Collision collision)
    {
        if (collision.gameObject.layer == layerNumber) 
            )
        {
            Debug.Log("Hit with Layermask");
            layerEnterCollision.Invoke();
        }
    }
    void OnCollisionExit(Collision collision)
    {
        if (collision.gameObject.layer == layerNumber)
        {
            Debug.Log("Hit with Layermask");
            layerEnterCollision.Invoke();
        }
    }

or

using UnityEngine;
using UnityEngine.Events;

public class LayerMaskExample : MonoBehaviour
{
    public LayerMask layerMask;
    public UnityEvent layerEnterCollision;
    public UnityEvent layerExitCollision;

    void OnTriggerEnter(Collider other)
    {
        if ((layerMask.value & (1 << other.transform.gameObject.layer)) > 0)
        {
            Debug.Log("Hit with Layermask");
            layerEnterCollision.Invoke();
        }
    }

    void OnTriggerExit(Collider other)
    {
        if ((layerMask.value & (1 << other.transform.gameObject.layer)) > 0)
        {
            Debug.Log("Left contact with Layermask");
            layerExitCollision.Invoke();
        }
    }
}