void EnqueueReadback ( [FRHICommandList](API\Runtime\RHI\FRHICommandList) & RHICmdList, [FRHIBuffer](API\Runtime\RHI\FRHIBuffer) * Buffer, [FCompletionCallback](API\Plugins\Niagara\FNiagaraGpuReadbackManager\FCompletionCallback) Callback )