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Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 3:03 pm
by c3kkos
Hello friends.

I'm a new luxcorerender user, within Blender 2.8.

I've taken a scene built around cycles and fired up with luxrender.

The first i've done is with all the caches enabled and Sobol NOT DENOISED

The second one is with BIDIR and METROPOLIS

The third one is the cycles reference.

All those setups took around 50 minutes to complete. The Metropolis one took slighty more, around 70 minutes

Using a i7-7700 only cpu compute device.



I confess i'm a bit disappointed about all the noise luxrender generates, but i feel it's due to a faulty setup in the scene.

I've only 2 lights in the scene. One inside the shower, one out of the windows, textured emission. (1 area light, 1 mesh light -1 face-)


The only thing i changed in lux configs is the Auto brightness of the camera (which, honestly, i don't know why it comes ON by default.. this is a bit confusing for the new users IMHO)

That said, i can attach the scene if this helps understand why -or if- i'm doing something wrong.

Luxrender is amazing.. thank you all for developing this great piece of software!

Re: Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 3:58 pm
by Dade
I guess you need to set the glass to architectural glass or use: viewtopic.php?f=5&t=1474

Re: Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 4:52 pm
by Sharlybg
will be better to have the blend file.
It is easy to kill performance when uncontroled artificial light and env light are mixed for new user. Also sometime Clamp value is not correctly set or not used at all.

in your scene there is alot of reflective surface so not sure PGI will help you that much.

Re: Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 4:57 pm
by Sharlybg
Dade wrote: Tue Nov 12, 2019 3:58 pm I guess you need to set the glass to architectural glass or use: viewtopic.php?f=5&t=1474
available in last builds ?

Re: Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 6:20 pm
by c3kkos
Thank you for your support!

I'll post the blend scene soon.

Re: Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 6:41 pm
by Dade
Sharlybg wrote: Tue Nov 12, 2019 4:57 pm
Dade wrote: Tue Nov 12, 2019 3:58 pm I guess you need to set the glass to architectural glass or use: viewtopic.php?f=5&t=1474
available in last builds ?
In LuxCore code yes, not sure about BlendLuxCore :?:

Re: Luxrender vs Cycles NOISE

Posted: Tue Nov 12, 2019 8:58 pm
by zeealpal
Also more than happy to help with scene optimisation, it can take a little to get used too sometimes from Cycles.

Often, doing things the Cycles way (especially with materials) can often be detrimental to Lux, and simpler setups often get the result your looking for.

Re: Luxrender vs Cycles NOISE

Posted: Wed Nov 20, 2019 11:51 am
by c3kkos
here you are the blend file, finally..

https://wetransfer.com/downloads/0d0d54 ... 000/f9248d

i used wetrasfer limited upload as the forum didn't allow me to... 10megs file.

Re: Luxrender vs Cycles NOISE

Posted: Wed Nov 20, 2019 1:11 pm
by Sharlybg
c3kkos wrote: Wed Nov 20, 2019 11:51 am here you are the blend file, finally..

https://wetransfer.com/downloads/0d0d54 ... 000/f9248d

i used wetrasfer limited upload as the forum didn't allow me to... 10megs file.
oK first observations :

1__ There is no env light in your scene so turn of Env cache

2__ turn on Clamp set it to 30 or 20 (useless fireflies killer)

3__ turn on Photon Gi :

pgi bath.jpg
4__ always use thicked walls. will save you a lot headache.

5__ some of your shader have too high albedo value (wall/fake spot/ marble) pur white isn't good for any renderer (70% max white = good perf )

Hope it help !

Re: Luxrender vs Cycles NOISE

Posted: Wed Nov 20, 2019 1:20 pm
by Sharlybg
this is 5mn render on my outdated i7 4930k.

Raw
5mn.jpg

Denoise
5mnDNSE.jpg
Another things.

1__ you switch to archglass and disable Lightracing


OR

2__ download last build and use hybrid glass