microfacet in a blenxd material and problem on a certain render node.

[jstrob]

I am rendering an animation on my render farm and one of my shader (on only on of my objects) is sometimes darker. The render is correct when I render on the farm on most of my nodes but is darker when rendering locally on my workstation and also darker on one of my render node...

For this shader I use the microfacet GTR (GGX) as a base in a VRayBlendMtl. I use vray 3.10.03 in max 2015.

Any idea how I could fix this?

[Morbid Angel]

absolutely sure that there is same vray is on all your machines?

[jstrob]

Yes,

In fact, the same machine, my main workstation, renders differently locally and via deadline...

[jstrob]

I managed to copmplete this render by blacklisting a node as soon as it was rendering this object darker.But I would like to pinpoint the problem.

[vlado]

Can you get me a scene for this? It looks odd definitely.

Best regards,
Vlado

[jstrob]

sent on your email

[vlado]

Thanks - I got it. We'll try to reproduce this here.

Best regards,
Vlado

[matanov]

Hi Jocelyn,

The problem seems to be in a bugged Falloff texture (nothing to do with GGX or VRayBlendMtl). If you copy the original material to a new slot and assign it again to the object, the problem will go away.

I see you are using Falloff direction "object", but the slot is empty in the original map, maybe it was set to something at some point and after removing it the issue appeared ? (just guessing..)

[jstrob]

Hi Peter!

Thanks you so much! you quickly found the problem!

The falloff should have been in the viewing direction. I didn't even noticed it was changed to object. My wacom pen probably slipped or something...

Still weird it doesn't deliver the same result on every render node. So I guess it's a 3dsmax falloff map bug.