Complex Stain Problem :(

[kemalettinozkan]

Hi everyone,

 

There is such a bad image on the walls (especially on dark color walls). I can't find a solution and I'm looking forward to your help. Thank You..

[John Dollus]

looks like a combination of a couple things. Add a low power light off to the left as a fill light and see if that takes care of it.

[kemalettinozkan]

Hello John, thanks for the answer. What you say may be useful, but I want to create a dim light environment so I use low light.This is a big problem for me.

 

(sorry for my bad english)

[John Dollus]

add it as a test only. If it fixes it, then you know it's a sampling issue. If it doesn't, then it's more a problem with your light source on the right or something else. what happens when you render it to an exr file and open in photoshop? is the dithering still apparent or does it change/shift?

[Francisco Penaloza]

What type of lighting are you using??

HDRI if so maybe you invert it gamma too much?? or the quality of your HDRI is not good.

Also, are you adjusting the image in your frame buffer?? if so maybe you are pushing too much the blacks???

are you using clamping in your settings??

Please post more info regarding your scene otherwise is hard to figure out.

[kemalettinozkan]

- There is no HDR in this scene. ( Usually vray plane )

- Lighting Subdivisions High (24)

- IMap- L.Cache values are sufficient

- Image Sampler 1-24- 0.005

- Material Subdivs enough

 

 

It becomes more pronounced when I make some contrast and white balance with Frame Buffer.

The same thing happens when I do post production in photoshop

A problem that I constantly experience in dark colors, which makes people crazy.

[Francisco Penaloza]

OK so your problem is RGB banding. This happens when you shift the colors beyond the RGB values of the image.

 

Fist be sure you are working in full float, do not use clamping in your render settings, be sure the gamma in 3D Max is default, this is 2.2

I would recommend to reset VRay values to default. On the latest VRay version you don't need to mess with materials or light subdivs.

 

 

If your image renders too dark and you are pushing the shadows up in post, then you need to put more light in your scene instead.

You can also save your image at 32Bits as HDRI or EXR formats, this will let you do post work with more light information.