noise on material ?

[tom182]

hi all,
dont usually do much interior stuff but I am having a problem with the noise on the walls and ceiling (its all the same material) I initially rendered it using IR+LC, tthen I read if a scene has glossy ref's not to use LC, so i opted for QMC think that might sort it, unfortunatley it didnt, and took forever to render, please see settings hopefully this will indicate as to the cause.
thanks
Tom

[panthon]

Hi!

First of all, i would look at your hdr as lighting contribution in the environment. HDR's as gi environment tend to be noisy. Try to lower the size of the hdr and blur it.

Secondly, I would increase values in AA settings, maybe 0-3 or 1-3 and threshold 0.01. You could try adaptive QMC too.

[ene.xis]

i suppose u need more samples to bounce around a little bit more...the noise is everywhere its just more aparent on the ceiling...

things that i guess contribute to increase the noise in ur image:
-the AA filter
-noise threshold in the QMC sampler too low
-Min samples in the QMC sampler

apart from that i would go for the LC anyway...or u would have to increase bounces and samples and ur rendertimes would prob go skyhigh..

just a side note...isnt the HDR only limited by its multiplyer in the map?i guess the it s pointless to have ur skylight multiplier to anytnhing else than one, just adjust the value in the map...

[jonnybefree]

i don't know, but why did everybody talk about dont use LC with glossys?
i'am usin it everytime, and had no problems with it.

[ene.xis]

i don't know, but why did everybody talk about dont use LC with glossys?
i'am usin it everytime, and had no problems with it.

yeahh!
same here.

[andrewjohn81]

it's light cache with glossy Refraction that you need to worry about. That might have been the confusion. Glossy reflection works fine.

[jujubee]

i don't know, but why did everybody talk about dont use LC with glossys?
i'am usin it everytime, and had no problems with it.

It has problems when you use 'use interpolation' in material settings when running from a saved solution.

@tom182

1) I'd take your IR off of high and put it to custom. Lower your min max to -4/-2 and bump the hsphs up to about 80.

2) Bump your QMC adaptive amount up to about .9 to speed things up. Noise difference wont be noticeable.

3) Raise your min samples to about 18. You could even try 1.5-2 for your Global subs multiplier.

4) I suspect much of your noise problem comes from the HDRs. Try subbing in regular lights and bumping up the subdivs to about 30.

[ene.xis]

2) Bump your QMC adaptive amount up to about .9 to speed things up. Noise difference wont be noticeable.

yeah, but the GI quality would be diminuished...

3) Raise your min samples to about 18. You could even try 1.5-2 for your Global subs multiplier.

it would still be noisy...i guess it needs more light coming in...

4) I suspect much of your noise problem comes from the HDRs. Try subbing in regular lights and bumping up the subdivs to about 30.

jujubee if he just bumps up all the subd and subd multipliers in vray the rendertimes will be ridicolous and u reduce the overall GI quality by increasing the adaptive QMC...so no point...i would really replace the secondary bounces to LC and bump up the HDR value controling the overall amount of light with the collor mapping....

[jujubee]

yeah, but the GI quality would be diminuished...

Not really. Look here: http://www.spot3d.com/vray/help/VRay...amples_qmc.htm

it would still be noisy...i guess it needs more light coming in...

I agree - but it will reduce it a little. The light multiplier needs to be rasied - but the main issue is subdivs.

jujubee if he just bumps up all the subd and subd multipliers in vray the rendertimes will be ridicolous and u reduce the overall GI quality by increasing the adaptive QMC...so no point...

If you tied it in with the rest of my suggestions he could possibly reduce current render times.

[tom182]

guys have it sorted,
I just applied panthon reccommendations and hit render, no hdri, threshold at .01 checked back at the scene and it rendered fine. I just saw the rest of the replies now so i will go through them and refine it more. @ ene.xis yeah your right or at least I believe thats true, The value in the hdr is higher than one because I didnt start off with a hdr in that slot and hence the value.
thanks all,
Tom