Instanced Indirect Rendering in UE4

Computes everything in compute shaders on the GPU, including LODs and frustum culling.
No GPU-CPU stalls anymore, it’s faster than HISM or ISM.

Since around 4.22 Epic has exposed indirect rendering via the RHI mostly because of Niagara, but this is a custom rendering component so there’s no overhead and is therefore faster where it needs to be.

Primarily used to render large vertex-animated armies.