Collider.isTouching for 3D colliders

Question

if (colliderBox.isTouching (col) && col.CompareTag("barrier")) {
        score++;
        this.GetComponent<Renderer> ().material.color = col.GetComponent<Renderer> ().material.color;
    }

    if (spriteBox.IsTouching(col) && col.CompareTag("barrier") ) {
        Debug.Log (col);
        Debug.Log (colliderBox);
        SceneManager.LoadScene (mainMenu);
    }

Currently in my code, I was using a onTriggerEnter, to detect a collision with an object called 'barrier', but I have had to replace my 2d spriteBox and 2d colliderBox with 3D objects, and now isTouching is not a property of 3D colliders. I can not find a simple replacement. What can I replace them with?

Answer 1

There is no equivalent version of the isTouching function for 3D collision but you can roll your own. When OnTriggerEnter, store both colliders involved in a collection. When OnTriggerExit is called, check for both colliders involved and if already exit in the collection, remove them from the collection. This is what I am doing in this post with the CollisionDetection script.

Attach the CollisionDetection script to the objects that will be colliding.

To check if Collider is touching another Collider, change:

if (colliderBox.isTouching (col) && col.CompareTag("barrier")) { }

to:

if (CollisionDetection.IsTouching (colliderBox.gameObject, col.gameObject) && col.CompareTag("barrier")) {  }

---

You can also add ExtensionMethod for the CollisionDetection class:

public static class ExtensionMethod
{
    public static bool IsTouching(this Collider collider, Collider otherCollider)
    {
        return CollisionDetection.IsTouching(collider.gameObject, otherCollider.gameObject);
    }

    public static bool IsTouching(this GameObject collider, GameObject otherCollider)
    {
        return CollisionDetection.IsTouching(collider, otherCollider);
    }
}

Now, your if (colliderBox.isTouching (col) && col.CompareTag("barrier")) code should work without changes assuming that colliderBox is a type of Collider or GameObject.