RaycastCommand.ScheduleBatch assertion failed when using large buffers

Unity Engine
,
1

Hello,

I’m using RaycastCommands to gain a bit of performance when casting millions of rays in Unity 2018.3.1, but I’m getting a strange message if (and only if) I use large buffers.

Here’s the code (you can just attach it to some object and press play):

Script

using Unity.Collections;
using Unity.Jobs;
using UnityEngine;

public class RaycastCommandExample : MonoBehaviour{

    public int raycastCount = 2048*2048;
 
    [ReadOnly] private NativeArray<RaycastHit> results;
    [ReadOnly] private NativeArray<RaycastCommand> commands;

    void Start() {

        results = new NativeArray<RaycastHit>(raycastCount, Allocator.TempJob);
        commands = new NativeArray<RaycastCommand>(raycastCount, Allocator.TempJob);

        for (int i = 0; i < raycastCount; i++) {
            commands[i] = new RaycastCommand(Vector3.zero, Vector3.forward, 1);
        }

        JobHandle handle = RaycastCommand.ScheduleBatch(commands, results, 32, default(JobHandle));
        handle.Complete();
    
        //...do something with results array entries

        commands.Dispose();
        results.Dispose();
    }
}

When raycastCount is lower than a certain value (that in my case happens to be 1568529), I get no messages.
But when I use a higher value I get this:

4096603--358186--upload_2019-1-13_12-4-19.png

Does anybody know what is happening?

Thanks in advance,
Francesco

1 Like
2

I have exactly the same issue.
Anyone know if this is a new problem?
I’m new to the job system so don’t know if this has always been the case. I may try a slightly earlier Unity version to test.

1 Like
3

I’ve tried different versions (2018.1, 2018.2, 2018.3) and all have this problem.
Still didn’t figure out the cause…

1 Like
4

No not sure either.
As far as I can tell my code still works as intended with all batched raycasts completed, so I think it may just be an erroneous assert.
Does your code still work as intended, or you can see other issues in addition to the error message?

5

Everything works fine. All the rays in the batch do what they should.

6

A wild guess but I think they probably limit the amount of ray according to what the max size a batch buffer can handle.

I ran into this issue before, I decided to divide by groups the rays then use a job to initialized the commands, then batch the raycast, something like this.

  protected override JobHandle OnUpdate(JobHandle handle)
  {
    for (int i = 0; i < groups.Length; ++i)
    {
      int Length = groups[i].NumberOfRaysOnGroup;
   
      NativeArray<RaycastCommand> raycastCommands = new NativeArray<RaycastCommand>(
        Length, Allocator.TempJob, NativeArrayOptions.ClearMemory
      );
      NativeArray<RaycastHit> raycastHits = new NativeArray<RaycastHit>(
        Length, Allocator.TempJob, NativeArrayOptions.ClearMemory
      );

      InitializeRaycastCommandJob setupRaycastsJob = new InitializeRaycastCommandJob()
      {
        Raycasts = raycastCommands,
        Tracer = Rays_LUT[i]
      };
      //Schedule the commands
      JobHandle setupDependency = setupRaycastsJob.Schedule(Length,
        Length / Job_Settings.InitializeRayCastCommandJobDivider, handle);
      //Schedule the rays on batch
      JobHandle raycastDependency = RaycastCommand.ScheduleBatch(raycastCommands,
        raycastHits, Length / Job_Settings.MinimumRaysPerJobDivider, setupDependency);
    }
  }
1 Like
7

Good workaround! Thanks for sharing!!
Do you think the max batch size is something hard coded? 'Cause to me only lengths higher than 1568529 produce this error. This is not a common number…

8

I don’t think is a hard coded value, more of like how much can your memory handle, mostly because for you 1568529 but for me is 1569748.

1 Like