RayCast

[ViachaslauBusel]

Hello, I cannot get the collisions of the ray with objects. What am I doing wrong?

   Box box = new Box(50, 1, 50);
            Vector3 position = new Vector3(25, 0, 25);
            var boxIndex = simulation.Shapes.Add(box);
            simulation.Statics.Add(new StaticDescription(position, Quaternion.Identity, new CollidableDescription(boxIndex, 0.1f)));


            Buffer<RayHit> Results;
            bufferPool.Take(1, out Results);


            var hitHandler = new HitHandler { Hits = Results };

            simulation.RayCast(new Vector3(25, 50, 25), new Vector3(0,-1,0), 200, ref hitHandler);

            if (hitHandler.Hits[0].Hit)
            {
                Console.WriteLine("hit happened!!!");
            }
            else Console.WriteLine("hit not detected"); 

HitHandler

``` public unsafe struct HitHandler : IRayHitHandler { public Buffer Hits; public int* IntersectionCount; [MethodImpl(MethodImplOptions.AggressiveInlining)] public bool AllowTest(CollidableReference collidable) { return true; }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public bool AllowTest(CollidableReference collidable, int childIndex)
        {
            return true;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void OnRayHit(in RayData ray, ref float maximumT, float t, in Vector3 normal, CollidableReference collidable, int childIndex)
        {
            maximumT = t;
            ref var hit = ref Hits[ray.Id];
            if (t < hit.T)
            {
                if (hit.T == float.MaxValue)
                    ++*IntersectionCount;
                hit.Normal = normal;
                hit.T = t;
                hit.Collidable = collidable;
                hit.Hit = true;
            }
        }
    }

</details>

[ViachaslauBusel]

As I understand it, the IRayHitHandler.OnRayHit method is called every time the ray hit with an object. And in the example of the OnRayHit method I took, several rays were transmitted and the one ray with the nearest hit point was sampled. and I didn't set the initial parameter "T = float.MaxValue;"

[RossNordby]

As I understand it, the IRayHitHandler.OnRayHit method is called every time the ray hit with an object.

That's correct, with a nuance- potential hits that got filtered out by AllowTest or by maximumT test will not be reported.

I didn't set the initial parameter "T = float.MaxValue;"

Yup:

ref var hit = ref Hits[ray.Id];
if (t < hit.T)

This checks the reported t value against the buffer-stored hit. If Hits has not been initialized before and came from an unmanaged memory source, the values in the hit reference are undefined. If they happen to be cleared, then hit.T will be 0, which will reject any hits. Initializing the hit.T value prevents that.