@Guillaume.Abadie I was reading up on this paper, I think you should take a look at it:
This paper includes how they achieve a TAA algorithm that looks so much better than anything I’ve seen in the past 5 years including the current TAA in Unreal and DLSS. I’m talking lightyears ahead.
“That is, we use the raw render of the previous frame and the current frame, but nothing more. That way, we prevent any long ghosting trails caused failed rejects, and we reach a stable and final result in only two frames, making our technique very responsive.”
This right here, uses a very cheap TAA while preventing ghosting. The latter was something that TSR aimed to achieve but it still has issues with foliage even if the material is outputting velocities. And TSR is not cheap.
Unreal Engines’ TAA default is 8 jitter samples and infinite frame re-use. Same goes for upscalers like DLSS. There is no combination of CVARS to fix unreals TAA. UE’s TAA is simply outdated and terrible in motion, so basically all the time except in screenshot 
. (unless it’s on at 4k as we discussed together already).
Make no mistake, the studio that owns Decima updated their latest game with a worse version of their TAA ruining motion clarity after some idiotic complaints about slight shimmering on grass which should have been mitigated with mips, and shaders.
This is miles ahead of anything I’ve seen, I’ll most likely be trying to work on implementing this in unreal if I even can as I am not an Engine Programmer.
I do not care about slight shimmering. Not everybody should not be subjected to motion smearing in their game which has been the case for many years in deferred rendered games in UE.
I want good motion clarity while handling specular issues. That is something Unreal has not offered at 1080p with deferred rendering.
They had low quality motion vectors, and used FXAA as a fallback.
Yet it looks better than UE5 current option in real motion because all the ghosting you see disappears in 16ms and it has no weird smearing.
With UE5’s superiors motion vectors, and this “raw” frame could work very well with a SMAA fallback. Cheaper than TSR and more clear if properly approached.
Unreal needs this already, build on top of this idea. It’s been long overdue and you have the correct background more than anyone to implement it.