3D array flattening / unflattening to / from compute shader

Hello,

I'm currently using compute shaders to compute 3D arrays of voxels and I'm experiencing some kind of "reversed" 3D coordinate issues, i.e X and Z coordinates seem to be reversed. I am suspecting this is because of the way Unity tranfers a 3D array between the CPU and the GPU using a compute shader.

My question is : how does Unity flattens (and "unflattens") a 3D array when calling `ComputeBuffer::GetData()` or `ComputeBuffer::SetData()` ?

When I do this on the CPU, I'm nesting loops in the X, Y, Z order, ie :
for (int x = 0; x < size; ++x) { for (int y = 0; y < size; ++y) { for (int z = 0; z < size; ++z) { flattened3DArray[x + size * (y + size * z)] = actual3DArray[x, y, z]; } } } I am suspecting that, internally, Unity is doing that in the Z, Y, X order instead of X, Y, Z, which would explain my issue.

You're gonna say that I just have to try and see by myself. That's true, but I'm still asking the question because I'm wondering whether the behaviour of Unity regarding this is well-defined or if it is some kind of OS or hardware dependent thing, which isn't something I can't check by myself. And also because it's painful to setup. :D

Thanks for your help !