Raycast(Vector3 origin, Vector3 direction) Bug

Unity Engine
,
1

I wrote some script to check if a vertex is inside cube, but Raycast without RaycastHit is not working.

Here is the code.

void OnDrawGizmos()
    {
        Gizmos.color = Color.red;

        foreach (Vector3 point in hitPoints)
        {
            Gizmos.DrawSphere(point, 0.01f);
        }
    }

Raycast(Vector3 origin, Vector3 direction)

  void Update()
    {
        hitPoints.Clear();

        Vector3 origin = transform.position;

        foreach (Vector3 vert in vertices)
        {
            int count = 0;

            Vector3 worldPoint = transform.TransformPoint(vert);

            if (Physics.Raycast(worldPoint, Vector3.up))
            {
                count++;
            }
            if (Physics.Raycast(worldPoint, Vector3.down))
            {
                count++;
            }
            if (Physics.Raycast(worldPoint, Vector3.left))
            {
                count++;

            }
            if (Physics.Raycast(worldPoint, Vector3.right))
            {
                count++;

            }
            if (Physics.Raycast(worldPoint, Vector3.forward))
            {
                count++;
            }
            if (Physics.Raycast(worldPoint, Vector3.back))
            {
                count++;
            }

            if (count == 6)
            {
                hitPoints.Add(worldPoint);
            }
        }
}

7992807--1027137--ķ™”ė©“ ģŗ”ģ²˜ 2022-03-25 150202.png
7992807--1027137--ķ™”ė©“ ģŗ”ģ²˜ 2022-03-25 150202.png1273Ɨ893 21.6 KB

No Spheres are showing means hit count wasnā€™t 6.

Raycast(Vector3 origin, Vector3 direction, out RaycastHit hitInfo)

  void Update()
    {
        hitPoints.Clear();

        Vector3 origin = transform.position;

        foreach (Vector3 vert in vertices)
        {
            int count = 0;

            Vector3 worldPoint = transform.TransformPoint(vert);

            RaycastHit hit;

            if (Physics.Raycast(worldPoint, Vector3.up, out hit))
            {
                count++;
            }
            if (Physics.Raycast(worldPoint, Vector3.down, out hit))
            {
                count++;
            }
            if (Physics.Raycast(worldPoint, Vector3.left, out hit))
            {
                count++;

            }
            if (Physics.Raycast(worldPoint, Vector3.right, out hit))
            {
                count++;

            }
            if (Physics.Raycast(worldPoint, Vector3.forward, out hit))
            {
                count++;
            }
            if (Physics.Raycast(worldPoint, Vector3.back, out hit))
            {
                count++;
            }

            if (count == 6)
            {
                hitPoints.Add(worldPoint);
            }
        }
}

7992807--1027140--ķ™”ė©“ ģŗ”ģ²˜ 2022-03-25 150250.png
7992807--1027140--ķ™”ė©“ ģŗ”ģ²˜ 2022-03-25 150250.png1093Ɨ911 20 KB

But with this code spheres are showing as I wanted to do.

What is wrong with Raycast without RaycastHit parameter?
It happened 2 years ago as I remember and itā€™s still not fixed.

2

Maybe narrow it down a little. What is the hitcount?

So itā€™s not fixed implies itā€™s been reported as a bug by you? Whatā€™s the case number? Iā€™ll ask the 3D physics team for you. Or is this you just assuming itā€™s a known issue?

3

Sorry for being late.
Hit count is the variable ā€œcountā€ in the foreach statement. I increased when Raycast was hit.

I didnā€™t report this bug because I didnā€™t know how to report exactly then.
So I am not sure if itā€™s a known issue.

4

Yeah, youā€™ve said. The issue or the root cause hasnā€™t been established so without some reproduction case submitted as a bug or a lot more detailed information, it isnā€™t going to be resolved either unfortunately.

So have you done anything to narrow it down? A test which expects a whole bunch of rays to detect a hit but if one doesnā€™t you just get nothing isnā€™t going to narrow it down. What if itā€™s just one ray and it always ā€œfailsā€ at 5? What if itā€™s always that ray? Maybe youā€™re too close to one edge? All Iā€™m doing is guessing at the first things that come to my head; Iā€™m asking if youā€™ve tried to narrow this down at all. If you have, which Iā€™d expect you to have, maybe you can pass that info along too, either here or in a bug report.

5

I just had a test with Raycast again and I found that the experiment I did before had errors.

  • It wasnā€™t hitting from inside the cyan cube, the hits were from surface of the cyan cube.(it wasnā€™t hitting backface)
  • The raycast was using default layer paremeter(All layers) so it was also hitting itself.

As you said I narrowed it down. Ran the script below.

void Update()
    {
        Vector3 origin = transform.position;
        Vector3 direction = target.position - origin;
        RaycastHit hit;

        if (Physics.Raycast(origin, direction))
        {
            Debug.Log("Physics.Raycast(origin, direction)");
        }

        if (Physics.Raycast(origin, direction, out hit))
        {
            Debug.Log("Physics.Raycast(origin, direction, out hit)");
        }

        Ray ray = new Ray(transform.position, direction);

        if (Physics.Raycast(ray))
        {
            Debug.Log("Physics.Raycast(ray)");
        }

        if (Physics.Raycast(ray, out hit))
        {
            Debug.Log("Physics.Raycast(ray, out hit)");
        }
    }

All had same results so there was no bug.

I still donā€™t know why there was difference between Physics.Raycast(origin, direction) and Physics.Raycast(origin, direction, out hit) because the only difference in code was just getting RayCastHit from it.
And the real problem is it couldnā€™t even make the count 6, it had to be less than 4.(Because it can only hit surfaces, 1 hit from green cube and 3 from itself is maximum expected.)
Maybe there was a mistake in object settings like layer, collider and etcā€¦

Anyway, I found that itā€™s working well now so thereā€™s no actual bug to report.

I am sorry for posting a flawed experiment, I had to check my settings and scripts first.

1 Like
6

Itā€™s all good. The main thing is youā€™re unblocked and can move forward so good luck!

If you can reproduce this consistently then I would absolutely consider reporting this as a bug because you are correct in that they should produce the same results.