Basic Collision

Unity Engine
1

Hi
i am new to scripting and am desperatly trying to learn it.

I need a simple as possible script that:
when the object with the script collides with a specific object, the object that has the script does something

i need this script so I can learn how to use collisions!
any help would be much appreciated
thanks!

2

The Unity Script Reference gives a great explanation and a few examples of code: Unity - Scripting API: Collider.OnCollisionEnter(Collision)

To find out if a particular object collided with the object the script is attached to, try something like this:

public var go_collide_with : GameObject; //in the Inspector, drag the object you want to collide with into this variable

function OnCollisionEnter(collision : Collision) {
    if (collision.gameObject == go_collide_with) { //did I collide with that object?
        //do something here
    }

I haven’t tested this code, but this is the concept!

3

thanks!
this script works perfectly!

much appreciated!

4

My pleasure! Does the script make sense to you?

And here’s an additional script that does basically the same thing, except it recognizes collisions with several different objects:

public var go_collide_with : GameObject[]; //in the Inspector, set the number of elements you want to collide with and then drag each one into a "slot" of this variable

function OnCollisionEnter(collision : Collision) {
    var b_collision : boolean = false;
    var go_one_object : GameObject;

    // Set "b_collision" to true if I collided with ANY of the objects in the "go_collide_with" array
    for (go_one_object in go_collide_with) {
        if (collision.gameObject == go_one_object) { //did I collide with this particular object?
            b_collision = true;
        }
    }

    // So, now that I've checked for collision with all of them -- did I collide or not?
    if (b_collision == true) {
        //do something here
    }
5

Also read up on Layers; these can be a useful tool to impose how different classes of gameObjects subscribe (or not) to things like Collisions and Raycasts.

6

thanks a million
both scripts do make sense and are incredibly useful!

and BoredKoi, i will take your advice and look into layers,

thanks!