Why do reflections have noise after update to 4.1?

After update my project to 4.1 i noticed this noise in reflections.

I also noticed that reflections went from smooth to noisy going from 4.0.2 to 4.1

Strange, I actually noticed the opposite. In 4.02 My reflections were noisy, then 4.1 made them much smoother.

That’s really odd, then again you’re reporting smooth reflections in 4.02, but mine where noisy.

I’ve discovered the problem, FXAA produces noise in reflections, after changing to temporal antialising the noise has gone.

Yes, this is a bug. A change from 4.0 to 4.1 reduced noise using some tricks and removed a special temporal AA pass specific to reflections, using just the final temporal AA to clean up the noise. When the final temporal AA isn’t used and FXAA is used instead the noise from SSR will never be cleaned up. I will fix this.

In the meantime if you wish to use SSR with FXAA set r.SSR.Temporal 1. This reenables the pass I disabled for 4.1. In either the default case of using temporal AA or using FXAA with r.SSR.Temporal the noise should be better than 4.0.

An additional bug with SSR+FXAA is the reflections won’t include translucency or fog.

I want to continue to improve the noise of SSR in the future but its a tug of war between reflection accuracy, performance, and noise.

Has this been fixed in 4.2?

Where do you set this: r.SSR.Temporal ?

In the code or is it a setting somewhere?

Also, the issue is still present in 4.2.

Sadly it’s still not fixed. I’m aware that TXAA is supposed to be superior, but in terms of performance and its effects on particles, FXAA is a much better suited for my game.

It should be fixed in 4.3.