Denoiser issues

[caretaker]

rendering a scene with 1000 samples came out ok-ish, however denoiser went bad and flashed some artifacts



Any ideeas?

[Dade]

I assume we are talking of Intel Oidn (you could try BCD denoiser too in your case). I assume you are also using normal glass (not architectural ?).

Oidn has some problem with the LuxCore glass because of the noise in the Albedo AOV. Reducing the amount of glass reflection can be a workaround to the problem but it will change how the scene look.

If you post a simplified the scene with just glass, background and some light source, I may be able to tell you more.

[B.Y.O.B.]

It looks to me like OIDN might extrapolate some bright fireflies into those artifacts. Clamping could help to counter this, or you could try to find which material/light source causes the fireflies and disable this influence, e.g. by turning off visibility in indirect specular rays.

[lacilaci]

As B.Y.O.B. said. Clamping should solve the issue, It happened to me few times when rendering unclamped with strong lightsources.

[caretaker]

That fixed the issue clamping with the recommended value by luxcore
Final results are here

viewtopic.php?f=3&t=1713