My Raycast isn't Hitting the Target

Unity Engine
1

Hello,

I’m working on a game where the AI uses a raycast to find their target. However for some reason when the Human AI uses their raycast it goes off in a random direction. It doesn’t even try to hit the enemy. The Alien’s raycast works perfectly though.

If anyone could shred some light on why this is occurring I’d be very grateful.

    GameObject FindClosestEnemy()
    {
        GameObject[] gos;
        gos = GameObject.FindGameObjectsWithTag(EnemyFaction);
        GameObject closest = null;
        float distance = Mathf.Infinity;
        Vector3 position = transform.position;

        foreach (GameObject go in gos)
        {
            Vector3 diff = go.transform.position - position;
            float curDistance = diff.sqrMagnitude;
            RaycastHit hit;
            BehindWall = true;
            Debug.DrawRay(transform.position, go.transform.position, Color.green);
            if (go.transform.FindChild ("Marksmen") == true)
            {
                Attackable = false;
            }

            if (go.transform.FindChild ("Marksmen") == false)
            {
                Attackable = true;
            }
            if (Physics.Raycast (transform.position, (go.transform.position - transform.position), out hit) && FriendlyFaction == ("Humans"))
            {
                print (hit.collider.gameObject.name);
            }

            if (Physics.Raycast (transform.position, (go.transform.position - transform.position), out hit) && hit.collider.gameObject.tag == (EnemyFaction))
            {
                BehindWall = false;
            }

            if (Physics.Raycast (transform.position, (go.transform.position - transform.position), out hit) && hit.collider.gameObject.tag == ("Wall"))
            {
                BehindWall = true;
            }
            if (curDistance < distance && BehindWall == false && Attackable == true)
            {
                closest = go;
                distance = curDistance;
            }
        }
        return closest;
2

3158855--240313--Raycast.jpg
3158855--240313--Raycast.jpg1680×1050 256 KB

3

Raycast wants a direction or point A to point B
When you take the enemy transform.posion and subtract your position, you are getting the difference between them.
so I would remove the subtraction part and give it a try.
if (Physics.Raycast (transform.position, go.transform.position, out hit)

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4

That is not correct. The first parameter is the origin position, the second parameter is a direction vector. You’re thinking of Linecast.

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5

Sadly that doesn’t seem to be helping, thanks for the try.

6

this helped me, it’s worth checking out:

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7

Thanks for all the help guys, I’ve switched to a linecast and that seems to be working just fine!

8

Glad you got it working!

Just so you know, this line wasn’t accurately showing you where your ray was going:

Debug.DrawRay(transform.position, go.transform.position, Color.green);

You may have an easier time formatting like this:

Vector3 direction = (go.transform.position - transform.position).normalized;
Ray ray = new Ray(transform.position, direction);

RaycastHit hit;
bool hitSomething = Physics.Raycast(ray, out hit); // distance defaults to infinity

if(hitSomething) {
    // do stuff
}

// DrawRay will draw from origin to (origin + direction), so you need to multiply in the distance.
Debug.DrawRay(ray.origin, ray.direction * Mathf.Infinity, hitSomething ? Color.green : Color.red);

Additionally, it seems that your logic is doing multiple identical raycasts per foreach iteration, which seems unnecessary. You should only need one raycast per loop, and then check the results for all your secondary conditionals.

2 Likes
9

Wow thanks for that knowledge! I really appreciate you taking time to expand on this for me. Raycasts and linecasts aren’t my strong point by any means, as you can probably tell. But this nice break down helps a lot!

1 Like