Question IJobParallelForTransform and Burst?

Greetings,
I am attempting to set up a TransformJob, and am curious to see if/how it will support the Burst, however I have one issue currently, and it is this line:

Code (csharp):

1. transform.localRotation = math.mul(StartRotation,
2. math.mul(quaternion.Euler(0f, _eulers.y, 0f), quaternion.Euler(_eulers.x, 0f, _eulers.z)));

It hereby states as so in the Burst Inspector .VM IR Optimisation Diagnostics window:

When I observed the quaternion.cs-code at the GitHub-repositorie, I couldn't find exactly where the

s e l e c t

is, except for in LookRotation and the safe option(s).

So, what am I doing wrong? Please help. ;w;

 

I'm not sure you're doing anything wrong so much as there's a problem with the quaternion.Euler( ) function you're calling interacting with the LLVM compiler (through Burst)
.

See
https://docs.microsoft.com/en-us/cp...orizer-and-parallelizer-messages?view=vs-2019

 

I have done a lot more testing now and it seems to come down to IJobParallelFor not supporting Burst? I even tried it empty, and it could not vectorize. I keep getting

loop control flow is not understood by vectorizer

even in an IJobParallelFor now? Error code is

unknown:0:0

by the by.

 

Here is an example of a simple IJobParallelFor that is not understood by the vectorizer:

Code (CSharp):

1.     [BurstCompile]
2.     public struct ForJob : IJobParallelFor
3.     {
4.         [ReadOnly]
5.         public NativeArray<float3> InPosition;
6.  
7.         [WriteOnly]
8.         public NativeArray<float3> OutPosition;
9.  
10.         [ReadOnly]
11.         public float DeltaTime;
12.  
13.         public void Execute(int index)
14.         {
15.             OutPosition[index] = OutPosition[index] + InPosition[index] * DeltaTime;
16.         }
17.     }

The Burst Inspector .VM IR Optimisation Diagnostics window responds henceforth with:

Remark: unknown:0:0: loop not vectorized: loop control flow not understood by vectorizer

What am I missing?

 

Ok, just tried the "successful vectorization" example from the SlideShare:

Code here:

Code (CSharp):

1.     [BurstCompile]
2.     public struct VectorizeDemo : IJob
3.     {
4.         public NativeArray<int> Inputs;
5.         public NativeArray<int> Outputs;
6.  
7.         public void Execute()
8.         {
9.             for(int i = 0; i < Inputs.Length; ++i)
10.             {
11.                 if(Inputs[i] >= 0)
12.                 {
13.                     Outputs[i] = Inputs[i];
14.                 }
15.                 else
16.                 {
17.                     Outputs[i] = 0;
18.                 }
19.             }
20.         }
21.     }

And it still gets:

Remark: unknown:0:0: loop not vectorized: loop control flow not understood by vectorizer

What is going on?

 

For the example, uncheck Safety Checks in the Burst inspector.

For everything else, I have never been able to get the autovectorizer to kick in when using types defined by Mathematics.

Keep in mind Burst still makes a huge difference even for scalar code, so unless this is a real bottleneck, I wouldn't fret too much about it.

 

It was a bit confusing to see how the "Safety Checks"-option works because I couldn't directly see the relation...

This is unfortunately the bottleneck of the project. It's the system that assigns rotations for the animation system which will be used for a few thousand NPCs' and the player's joints. This is the only significant system in the game that will run every frame, however I need the frametime bandwidth to also allow for AI state machine updates (runs 4 times per second) and culling/other graphics jobs (like mesh creation).

I have looked into vertex animation for distant NPC but unfortunately it has limits as it is not as dynamic. It would have to be switched between, and making a system for this could potentially be a little out of scope for now, but if there is no other option I might look into it next.

 

Thank you so much for this. :3c

The reason for the float3 is they are 3D-positions or Euler-rotations for objects. However, would it be more "efficient" to just use float4 and leave the .w at 0, using just .xyz?

 

Hmm, I have had a long think about data management for this now, and it seems that regardless of what I do there will unfortunately be a lot of floats floating around, but they could perhaps be grouped by something (but then we are back to why not just use float3-4s)? I am rather new to all of this and unfortunately kind of tied to Monobehaviours for legacy reasons.