Unity 5 - Physics.OverlapSphere not working

Question

I'm working on my first Unity game and I'm having a problem with this script.

void FixedUpdate ()
{
    Debug.Log ("dead is " + dead);
    dead = Physics.OverlapSphere (frontCheck.position, radius, whatIsWall);

    if (dead == true) 
    {
        Debug.Log ("Player died!");
        Invoke ("Reset", 1);
    }
}

void Reset()
{
    SceneManager.LoadScene ("Game");
}

I'm trying to make the bool dead true when the player runs into a wall, using a transform in front of the player. I was using Physics2D.OverLapPoint and it worked fine, but I had to change player's physics to 3D. I'm trying to use OverLapSphere now, but Im getting an error message "Cannot implicitly convert type UnityEngine.Collider[] to bool. What should I do to make this work? Im very much a beginner to Unity and coding in general, so it's probably a simple fix. Maybe I just need to try something else? thanks.

Answer 1

Better Approach

I believe a better approach to detect collisions is using OnColissionEnter. https://docs.unity3d.com/ScriptReference/Collider.OnCollisionEnter.html

That way you can have a simple check such as:

void OnCollisionEnter(Collision col) {
    if (col.gameObject.tag == "Wall"){
      dead = true;
    } 
}

Here is a short tutorial on that: https://unity3d.com/learn/tutorials/topics/physics/detecting-collisions-oncollisionenter

Using OverlapSphere

If for some reason you prefer OverlapSphere, then you need to know that it doesn't return a bool as you are expecting. Instead, it returns all colliders that overlap with the sphere.

https://docs.unity3d.com/ScriptReference/Physics.OverlapSphere.html

I believe what you are looking for is:

void FixedUpdate ()
{
    Debug.Log ("dead is " + dead);
    Collider[] hitColliders = = Physics.OverlapSphere (frontCheck.position, radius, whatIsWall);

    if (hitColliders.length != 0) {
        Debug.Log ("Player died!");


        Invoke ("Reset", 1);
    }
}