Touch through GameObject, best practice

Question

in the game I am doing atm you have an area with monsters. There are two modes to damage monsters :

1. tapping on them
2. casting spells on the ground

Tapping and damaging a monster works fine.

The problem : If I have selected a spell and want to cast it on the ground, the monster collider blocks my touch of the ground behind the monster.

My solution was to disable the monster collider when I want to cast a spell.

    GameObject[] toDisable = GameObject.FindGameObjectsWithTag ("Touch");

    foreach (GameObject g in toDisable) {
        g.GetComponent<Collider>().enabled = active;
    }

And ... it works.

Now my question is : Is this an adequate solution? They say GetComponent is slow, but I guess with 20 to 30 monsters running around it should be fine? Anything else that could be done? Maybe there is some Unity magic I am not aware of.

Answer 1

The problem : If I have selected a spell and want to cast it on the ground, the monster collider blocks my touch of the ground behind the monster.

No need to disable colliders. Just assign different layers to monsters, spells and ground. Then use the collision matrix to specify that a spell doesn't collide with monsters.

(The same process, using LayerMask if you are using RayCasting)

They say GetComponent is slow, but I guess with 20 to 30 monsters running around it should be fine?

It's slow because there's no caching of Components in the Mono side of the scripts. Every GetComponent is forwarded to the native code which iterates through all components attached to a given GameObject. More objects, more calls. More components more thing to iterate through.

Definitely an overkill in this specific context.

Answer 2

I think I have a solution: Set the LayerMask of the PhysicsRaycaster accordingly.

public LayerMask normal; //Everything
public LayerMask attack; //Floor
public PhysicsRaycaster rayCaster;

void Update() {

    attackAllowed = Input.GetKey (KeyCode.Space);

    rayCaster.eventMask = attackAllowed?attack:normal;

}

Works like a charm.