clamp output on bidir

[nocivo]

Hello,
clamp output is very useful to remove fireflies on path tracing. Is it easy or possible to implement it also on bidir?
On bidir there aren't too much fireflies, but in some cases in interior complex scenes with a lot of caustic (glass and metal material) it could be useful.

On lux classic there was fireflies rejection option that work well but use a lot of memory, changing based to the scenes. Anyway if clamp output is not possible to implement , it would be good to have the old fireflies rejection option or something to avoid the fireflies. Now I'm lowing "Max consecutive rejects" to avoid fireflies, but it introduces a little of bias.

Thanks.

[Sharlybg]

I think i've finally find a way to fix this. I render everyday with bidir engine ( and also currently while answering you).

First Bidir is a different beast at a coding and philosophy level and there is already something planned to boost it soon. but currently there are some simple trick to do with it to get the jpb done:

___ work always with eye path = 3 __ light path = 3 when you're setting up your render (lighting) only increase to 4 & 4 or more

___ reduce max consecutive rejection to 128 ( this one act like a clamping believe me)

___ For each kind of scene there is a correct light strategy to select be sure you're on the right one by making test between log power / power mod. be carefull bidir is very sensitive to this. For example monday i got a problem with a seriously noisy interior render after 10h render But when simply switch to Power instead of log power i got the 10h render noise convergence in only 30mn

[Dade]

Yes, I can look into the problem of extending variance clamping support to BiDir: https://github.com/LuxCoreRender/LuxCore/issues/92

[kintuX]

What about supersampling? IIRC, was already possible with BiDir. That also improves quality...

[Dade]

What about supersampling? IIRC, was already possible with BiDir. That also improves quality...

What do you mean with "supersampling" ? The Mitchel pixel filter supersampling ? It is already available under then name of "MITCHELL_SS"(https://github.com/LuxCoreRender/LuxCor ... hellss.cpp). The default pixel filter is Blackman-Harris like in old Lux.

[B.Y.O.B.]

If you select "Mitchell" as pixel filter, you get mitchell with supersampling: https://github.com/LuxCoreRender/BlendL ... ig.py#L206

[kintuX]

What about supersampling? IIRC, was already possible with BiDir. That also improves quality...

What do you mean with "supersampling" ? The Mitchel pixel filter supersampling ? It is already available under then name of "MITCHELL_SS"(https://github.com/LuxCoreRender/LuxCor ... hellss.cpp). The default pixel filter is Blackman-Harris like in old Lux.

If you select "Mitchell" as pixel filter, you get mitchell with supersampling: https://github.com/LuxCoreRender/BlendL ... ig.py#L206

I meant Supersampling. So I thought it works internally on larger image (or is that oversampling?). Helps with reducing noise, as Thea & Indigo use it.

Anyway, Thank you both for pointing/clearing it to me.

[B.Y.O.B.]

Working with a higher-resolution image and downscaling it is quality-wise the best form of anti-aliasing, and memory wise the worst one. Are there really render engines that do this? Sounds like your RAM usage would explode.

[Dade]

Done: viewtopic.php?f=5&t=217

[nocivo]

Done: viewtopic.php?f=5&t=217

super fast. thanks a lot. I'am going to test.