Temporal AA did wonders/miracles when I was still using 4.11. When the camera moved, it caused some pixelation for a short while, but that was perfect for my game, since everything in my game almost never moves.
I then switched to 4.13, and now it doesn’t look smooth anymore when nothing moves. When I move the camera, everything looks smooth, but when it doesn’t move, everything becomes more and more pixelated till the point of almost no AA.
I thought, maybe it was my project settings, so I tried changing everything you could find in the Engine Scalability Settings, I also tried different values for r.TemporalAASamples and r.TemporalAASharpness. None of it fixed my problem.
I tried creating new projects, one in 4.11, one in 4.13. After setting all Engine Scalability Settings to max and going into the project settings to change the AA to Temporal AA, I found out that in 4.11 the Temporal AA does wonders, but in 4.13 it indeed doesn’t do anything if the camera and the object doesn’t move.
The differences are easiest to see at the top of the object, the part that is the furthest away from the camera.
What changed in 4.12 or 4.13 that caused this? It there a new option in 4.13 that I’ve missed?
I do agree that it seems the Default TemporalAA sample count/sharpness settings seem to have been tampered with and there is no documentation that reflects this. So, to be honest I’m not sure if this is a bug or a simple change that didn’t get mentioned.
Try changing these settings via console commands r.TemporalAASamples or r.TemporalAASharpenss
I found that these settings got close to 4.11 r.TemporalAASamples 16, r.TemporalAASharpenss 1
Although, I leave it up to you to find what works for you.
Alternatively, you can add a post process volume that has the screen percentage over 100 to get higher quality AA (only in game though). You can find this in the Misc section of the post process settings.
All 3 of the tests were done with samples set to 8, sharpness set to 1, and resolution set to 100%.
When I tried to change the samples to 16 in the 4.13 projects, it didn’t make a difference.
I decided to rollback to my project when it still used 4.11, to see the difference.
Not only is the 4.13 image pixelated, it also vibrates. My guess is that the vibration is for the AA, but I don’t think this is supposed to be visible. Somehow in 4.13 the AA doesn’t use the vibration anymore and the vibration is being shown to the user instead. This must be a bug in temporal AA.
It can easily be replicated, just run a 4.13 project with temporal AA, set the temporal AA sharpness to 0, and don’t move the camera. Maybe you need to adjust your view a bit to get a similar view as in my screenshots. Either way, you should see vibration, or at the very least some pixel movement. I saw it especially on the left side of the square block / chess board.
I was able to come up with a test case to reproduce this issue. There is definitely something going on with TemporalAA. I’ve logged a bug report for it here: Unreal Engine Issues and Bug Tracker (UE-37379)
You can track the report’s status as the issue is reviewed by our development staff.