Both Immediate/AsyncCompute passes are always executed in order on the render thread but other RDG passes can run in parallel.
With my previous change, RayTracingScene pass was changed to Compute/AsyncCompute to have the correct order on the GPU.
But when it was set to Compute (when AsyncCompute was disabled) it was running in parallel with passes it depends on which led to random crashes.
Because the dependency between passes was implicit, we needed a new flag to express the intent and get the desired order between execution lambdas.
On behalf of Zach Bethel.
#rb zach.bethel
#jira UE-141003
#preflight 61fb0d9e923ac18db7015160
#lockdown michal.valient
#ROBOMERGE-AUTHOR: aleksander.netzel
#ROBOMERGE-SOURCE: CL 18841970 in //UE5/Release-5.0/... via CL 18841984 via CL 18842341
#ROBOMERGE-BOT: UE5 (Release-Engine-Test -> Main) (v910-18824042)
[CL 18842374 by aleksander netzel in ue5-main branch]
- Implemented common transient page allocator in RHICore.
- Implemented XBox specific GPU page table mapping allocator.
- Extended RDG insights to support viewing heap visualization or page pool visualization.
#preflight 61d356682e0e436c725818bf
[CL 18504626 by zach bethel in ue5-main branch]
- Refactored RDG to support free-threaded execution of passes.
- Refactored renderer to use specific RHI command list variants in pass lambda. Immediate command list passes are forced to stay on the render thread, while other variants can be parallelized.
#rb christopher.waters
#ROBOMERGE-SOURCE: CL 16838717 in //UE5/Main/...
#ROBOMERGE-BOT: STARSHIP (Main -> Release-Engine-Test) (v836-16769935)
[CL 16838724 by zach bethel in ue5-release-engine-test branch]
- Refactored RDG to support free-threaded execution of passes.
- Refactored renderer to use specific RHI command list variants in pass lambda. Immediate command list passes are forced to stay on the render thread, while other variants can be parallelized.
#rb christopher.waters
[CL 16838717 by zach bethel in ue5-main branch]
- New Drain() method on FRDGBuilder; will flush all pending work.
- Drained passes are not culled; resource lifetimes are extended; async compute fences are optimized as best as possible but fence joining may occur after the drain.
- Batch up and pre-build all resource transitions. This is a prerequisite for parallel command lists.
- Removed ServiceLocalQueue passes with built-in RDG AddDispatchHint().
#jira UE-114622
[CL 16393495 by zach bethel in ue5-main branch]
- Replaced legacy transient support from RDG and replaced with new API.
- Reworked acquire / discard operations a bit and added RHI validation to track correctness.
- Reworked RDG barrier batching to include acquire / discard operations.
- Hardened render pass merging logic and expanded to support lifetime extension of transient resources.
- Added transient tag to RDG insights to track which resources are transient.
#rb luke.thatcher, kenzo.terelst
[CL 15726534 by zach bethel in ue5-main branch]
