This project is a minimal example for using compute shaders in the Unreal Engine. The other examples out there are overly complicated for someone getting started, in my opinion.
FComputeShaderDeclaration in ComputeShaderTestComponent.h is how we bind our buffers from our Unreal classes to the compute shader. You write one of these for each of your compute shaders.
UComputeShaderTestComponent in ComputeShaderTestComponent.h contains the structured-buffer and unordered-access-views (UAVs) that we bind to the compute shader. We setup and bind to our compute shader in TickComponent, on the render command queue.
UDrawPositionsComponent in ComputeShaderTestComponent.h draws the positions from the UComputeShaderTestComponent using an UInstancedStaticMeshComponent (ISMC).
I couldn't figure out how to bind the compute shader to the ISMCs internal buffers. So, we are doing unnecessary copying back to the CPU and back to the GPU. I also copy from a FVector array to a FTransform array, that's a little ugly.
The compute shader is super basic, it just modulates positions with a sine function.
- The
LoadingPhasein the uproject file needs to bePostConfigInit - You must let Unreal know where to find your shader directly. I set this in the game mode in the module interface in ComputeShaderExample.h