Unity - Get list of gameobjects close to object clicked?

Question

I have a stack of balls of 4 colors some touching some not. When you click on one color ball I want to destroy that ball and any other balls of that color that are close. They may not be touching so collision wont work.

How do I detect gameobjects close but not touching that are the same color? Say half a radius away from the edge of the ball clicked.

Here are the two scripts I'm working with to create and touch the game objects.

public class SpawnBalls : MonoBehaviour {
public Rigidbody ball;
public float waittime = 0.5f;

// Use this for initialization
void Start () {
    spawn ();
}

// Update is called once per frame
void Update () {
    //Instantiate (ball);

}
public void spawn(){
    //yield WaitForSeconds(waittime);

        for (var i = 0; i < 10; i++) {
            Instantiate (ball);
        }
}

}

Selecting the balls

public class Ball : MonoBehaviour {

public Color[] colors;
private Color ballpicked;

// Use this for initialization
void Start () {
    GetComponent<Renderer>().material.color = colors[Random.Range (0, 4)];
}

// Update is called once per frame
void Update () {

}
 void OnMouseDown(){
    if (Input.GetKey("mouse 0")){

        ballpicked = GetComponent<Renderer> ().material.color;

        //if (ballpicked == "Any other balls within a half a ball width") {

        //}

        Destroy (gameObject);
    }
}

Answer 1

There's a few physics methods you may be interested in:

• OverlapSphere - Returns an array with all colliders touching or inside the sphere.
• OverlapBox - Find all colliders touching or inside of the given box.

You can utilize one of the above to select all the objects within a specified area. Then you can iterate through them and just keep the ones you're interested in.