Grain in shadows (VRay standalone)

[paulDryzen]

Hi,

its me again. This time with a more serious problem

If you take a look at the 2 images in this post you can see that the one rendered with VRay standalone has a lot more grain than the version rendered directly in the maya renderview.

Hm, damn: The name of the images are wrong, the grainy one is from vray standalone

We found this problem a few days ago, since I don´t wan´t to post a problem which I cannot explain. In that case it is a little difficult because we couldn´t find anything that is causing this problem.

So here is a list of what we have checked.

1. We have exported the scene to a vrscene and have checked every value of the shader; light; DOF settings; rendersettings and everything which stand inside the vrscene. No value was different to the values in Maya.
2. We have tested the scene with almost everything switched of and on and we are pretty sure that the shadows of the VRay rect light is somehow causing that error/grain.

I hope that explains the thing a bit.

Greetings Paul

Btw. We are using V-Ray: V-Ray for Maya version 1.50.00 from Apr 26 2010, 07:28:10 for Maya 2009 64bit.

[vlado]

Can you get us a scene for that which you can send to me at vlado@chaosgroup.com ? It would be very helpful to track down the problem.

Best regards,
Vlado

[paulDryzen]

Hi,

is there some new information regarding this problem?

Greetings Paul

[vlado]

Still working on it; the scene takes a while to render

Best regards,
Vlado

[paulDryzen]

Hi,

maybe we have found the "problem". In our export script the set the gamma value back to 1.0, so the dmc sampler needs to handle a lot more contrast during rendering. So we think that this is causing the grain in the darker areas of the pictures since our rendersettings are adjusted with gamma 2.2. We will change the export script and check if this will help us with the grain problem.

Greets Paul