Blotchy no matter how high settings!

[Roodogg]

Hi Everyone. Having a bit of a nightmare here... Any help would be awesome.

 

Trying to do a preview render on a single quad core with 8gb ram but no matter how high I set everything, I can't get rid of the splotchiness!![ATTACH=CONFIG]44634[/ATTACH]

 

Please see the attached image.

 

Settings are:

 

3ds max vray 1.5 sp4

 

DMC image sampler min 4 max 16

Irr Preset High

LC 2500, sample size 0.01

global subdivs multiplier 10.

 

This image (rendered at 2500px wide) took nearly 5 hours to render and the quality is poor!!!.

 

I am using vray sky, photometric lights, vray shadow with area shadows disabled.

 

I'm sure I just need to up the settings but they're already quite high and would expect 'smoother' results!?

[AubreyM]

Yea these settings are high.

What are the settings for the Hsph subdivisions and the interp samples?. About 60-65 and 20-25 should be good.

What is the noise threshold? .01 should be ok but maybe you could try .002 or so.

light subdivisions should be checked as well maybe you need to bump those up a bit.

Also the min rate and max rate should be tweaked as well. Change the preset to custom and start with about min -3 and max -5, you may have to play with that a bit.

You should be able to get rid of those blotches with a lot lower setting.

If none of the suggestions work then maybe post a screen shot of all your settings.

 

Good Luck.

[Roodogg]

Hey thanks for your help. I've already played around with pretty much everything in the Render setup dialogue, nothing gets rid of the lack of definition on the cornice (Which is fairly high detail.

 

I've painstakingly replaced all of the photometric lights with vray ies and bumped up the shadow subdivs.

 

I think there's something wrong with the light cache!!?[ATTACH=CONFIG]44635[/ATTACH]? The screen attached shows the calculation phase and i'm sure it looks wrong. Can you shed any light on that?

[BrianKitts]

you're using a cannon to kill a mosquito, large splotchy noise like that normally a product of not enough hemispherical subdivisions. and small noise is a product of not enough image sampling, either to low a threshold or in not a high enough maximum.

 

try this one on for size and see what it gets you.....

 

DMC 1/8

noise thresh .005

 

medium preset

IRR subs 80/20

LC 1000 samples @ .01

 

leave everything else it's default settings.

 

with the time savings that will get you, you can probably afford to turn on detail enhancement to really clean out the tights spots in the cornice, but you'll take a rendering hit on time for it.

[Roodogg]

Hi Thanks. It's not fixed it. Strangely though, when I render with override material, where everything is white, it looks perfect so it only occurs when i have textures applied. Very frustrating and it's just going to have to go out at substandard quality.

[Roodogg]

Well I've had an epiphany. And that is. Not everything in your scene should generate GI. Especially cornices.

[erickdt]

Your issue is Hsph subdivision for sure. High settings are required in low light situtations or in situations where the light illuminating an object is bounced light. An easy, although not 100% physically accurate, work around is to put a VRay plane light under the floor pointing up, exclude the floor and tweak the multiplier until you get the right result. The other option is to turn up the multipliers for your first and secondary bounces to 1.0 and 1.0 in indirect illumination if they're not there yet.

 

The reason it looks good with your over-ride material, assuming it's a white material, is that white is the ideal reflective surface for getting light to bouce around. Once you start adding in different colored materials the bounce light is reduced.

 

Hope that helps!

 

E

Edited September 2, 2011 by erickdt

[aristocratic3d]

hi,

keep aside all the suggestions and attempts. Just play with the smoothing group of the model. Specially the moulding. I hope it will help.

I am from a mobile device and cant really see the image very clearly though.

Happy project.

[stormchaser]

hi,

keep aside all the suggestions and attempts. Just play with the smoothing group of the model. Specially the moulding. I hope it will help.

I am from a mobile device and cant really see the image very clearly though.

Happy project.

i dont think that will help, the problem is clearly of having not enough light samples erickdt has nailed the problem, it is quite common problem with scenes with low light.

[kippu]

did you try the brute force one though?

[salvador]

I've been having the same problem here and I think I just finally cracked it. Apparently (said like this since I'm not quite a V-Ray expert) V-Ray needs a certain amount of light samples to work with. When an interior scene is lit by Sun+Sky alone, the walls and ceiling are lit by bounced light only, and if you have deflectors such as curtains or blinds, the rays will be too scattered to get to a smooth surface look because of the low samples that could be collected. In my case, I turned back to the V-Ray lights on the windows, but checked "Skylight portal" and "Store with Irradiance map" on. Also used 24 shadow subdivs for each light. This way you can test and control the final quality with the sampler parameters.

I used IrrMap 80 / 40, LC 1500 @ 0.01, use LC for glossies on, Adaptive DMC 1-8 and Clr threshold on @ .005; also I put 3 global subdiv. mult. I just think this will take care of it.