Raycast always returns null | Brackeys Community | Page 1

meager haven Sep 17, 2022, 7:25 PM

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Hi, i'm working on an enemy AI for my game that uses a raycast to determine if it can fire upon you or if there's an obstacle in the way, but after i was done fixing another bug the raycast started to not give me any info (null) as if it didn't hit anything, eventhough it did

code:

if(Physics.Raycast(new Vector3(EnemyDirectionMeasurement.transform.position.x, EnemyDirectionMeasurement.transform.position.y, EnemyDirectionMeasurement.transform.position.z + 1), Vector3.forward, out hit, Mathf.Infinity))
        {
            hitObject = GameObject.Find(hit.collider.gameObject.name).GetComponent<UnitBehaviour>();
            if(hit.collider == preferedEnemy)
            {
                isEnemyInFireRange = true;
            }
            else
            {
                isEnemyInFireRange = false;
            }

            //Set isEnemyInFireRange to false if the raycast doesn't hit anything
            if(hit.collider == null)
            {
                isEnemyInFireRange = false;
            }
        }

rugged reef Sep 17, 2022, 7:34 PM

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What variable is null, exactly?

meager haven Sep 17, 2022, 7:35 PM

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hit.collider

rugged reef Sep 17, 2022, 7:35 PM

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That should throw a NullReferenceException, then, right?

meager haven Sep 17, 2022, 7:35 PM

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no

rugged reef Sep 17, 2022, 7:36 PM

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Well, you're calling hit.collider.gameObject, so if it were null, you'd get an exception.

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Are you sure it's null?

meager haven Sep 17, 2022, 7:37 PM

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I put a Debug.Log displaying hit.collider at the end and it throws a null

rugged reef Sep 17, 2022, 7:37 PM

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Did you put the Debug.Log inside the if-statement?

meager haven Sep 17, 2022, 7:37 PM

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nope

rugged reef Sep 17, 2022, 7:38 PM

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Great, so it didn't actually hit anything.

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as if it didn't hit anything, eventhough it did

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So it really doesn't hit.

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Then the code doesn't really say that much, sadly.

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I'll throw out some ideas for what could be wrong.

meager haven Sep 17, 2022, 7:39 PM

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rugged reef Then the code doesn't really say that much, sadly.

i can't really show you the entire code, as it's about 270 lines

rugged reef Sep 17, 2022, 7:39 PM

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I don't think the code is the important part either.

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I think it's the setup.

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Like colliders.

meager haven Sep 17, 2022, 7:39 PM

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basicly there's an empty gameobject that alsways turns towards the target and shoots the raycast

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that's how it's set up

rugged reef Sep 17, 2022, 7:40 PM

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Okay, I have an idea.

meager haven Sep 17, 2022, 7:40 PM

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i even did a Debug.DrawRay with the same parameters as the raycast and it goes through walls and stuff so it's hitting but the raycast doesn't realize that

rugged reef Sep 17, 2022, 7:41 PM

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Hm, can I see your ray?

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Well, the code for drawing it.

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I was going to suggest that. :P

meager haven Sep 17, 2022, 7:41 PM

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sure give me a sec

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Debug.DrawLine(new Vector3(EnemyDirectionMeasurement.transform.position.x, EnemyDirectionMeasurement.transform.position.y, EnemyDirectionMeasurement.transform.position.z + 1), GameObject.Find(preferedEnemy.GetComponent<Collider>().gameObject.name).transform.position, Color.red, 0, false);

rugged reef Sep 17, 2022, 7:42 PM

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Hmm.

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That doesn't look like the same ray.

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The raycast uses Vector3.forward as the direction.

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I'm just worried that's the issue.

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I'd extract the origin and direction as variables, possibly into a Ray.

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And use that Ray for both the Raycast and the DrawLine/DrawRay.

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Just to make sure.

meager haven Sep 17, 2022, 7:43 PM

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ok give me a minute

white shadow Sep 17, 2022, 7:43 PM

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also, the origin can be determined more easily:
EnemyDirectionMeasurement.transform.position + Vector3.forward
will give you the same result as
new Vector3(EnemyDirectionMeasurement.transform.position.x, EnemyDirectionMeasurement.transform.position.y, EnemyDirectionMeasurement.transform.position.z + 1),
while also being more concise.

rugged reef Sep 17, 2022, 7:44 PM

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Yeah, I think simplifying the code can make it easier to spot the error.

meager haven Sep 17, 2022, 7:46 PM

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white shadow also, the `origin` can be determined more easily: `EnemyDirectionMeasurement.tra...

i know, the thing is the origin point is inside another object so the extra code is there to cast the ray outside this object

rugged reef Sep 17, 2022, 7:47 PM

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No, the code is literally equivalent.

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There is no difference between your code and his; it's just a simplification.

meager haven Sep 17, 2022, 7:47 PM

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rugged reef And use that `Ray` for both the `Raycast` and the `DrawLine`/`DrawRay`.

so now the ray starts from a weird point that's a bit outside the object it starts from but not in the right direction and it goes to 0, 0, 0

rugged reef Sep 17, 2022, 7:47 PM

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meager haven so now the ray starts from a weird point that's a bit outside the object it star...

Perfect, so that's your problem, right?

meager haven Sep 17, 2022, 7:48 PM

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rugged reef There is no difference between your code and his; it's just a simplification.

but wouldn't it hit the object it is in?

rugged reef Sep 17, 2022, 7:48 PM

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If your code does that, then yes, this wouldn't change it.

meager haven Sep 17, 2022, 7:48 PM

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rugged reef Perfect, so that's your problem, right?

well yeah i guess but 1. i don't know how to fix it and 2. it still goes through a wall but doesn't realize that

meager haven Sep 17, 2022, 7:48 PM

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rugged reef If your code does that, then yes, this wouldn't change it.

ight

white shadow Sep 17, 2022, 7:49 PM

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meager haven but wouldn't it hit the object it is in?

I am adding Vector3.forward, which is literally 0, 0, 1. So that comes out to the exact same thing as doing new Vector3(x + 0, y + 0, z + 1), which you did.

meager haven Sep 17, 2022, 7:49 PM

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white shadow I am adding `Vector3.forward`, which is literally `0, 0, 1`. So that comes out t...

okay

rugged reef Sep 17, 2022, 7:49 PM

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Okay, so how about you use a LayerMask instead?

white shadow Sep 17, 2022, 7:49 PM

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Though I am assuming that you will want to be using local directions for your ray, rather than global ones in the first place.

rugged reef Sep 17, 2022, 7:50 PM

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Yeah, a simple one would be Physics.Raycast(transform.position, transform.forward, out var hit).

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Then I would add a LayerMask to make sure it doesn't hit itself.

meager haven Sep 17, 2022, 7:51 PM

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rugged reef Then I would add a `LayerMask` to make sure it doesn't hit itself.

what do you mean

rugged reef Sep 17, 2022, 7:52 PM

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So, when you're shooting a Raycast, you can give it a LayerMask as a parameter.

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This will tell it which layers to ignore.

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You can assign layers to GameObjects.

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Like Player or Enemy.

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And you specify that your raycast just ignores the Enemy layer or only hits Player.

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It's probably not that simple, but layers can be useful here.

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But I'm not convinced your raycast would hit the enemy anyway...

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If you have a SphereCollider, and you shoot a raycast from inside it, it won't hit the sphere itself.

meager haven Sep 17, 2022, 7:53 PM

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rugged reef But I'm not convinced your raycast would hit the enemy anyway...

Yes it does i just tested it, now the raycast works but another part of my script is broken lol

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But thanks for the help guys

#Raycast always returns null