Strange shading artifacts on simple geometry - vray 3.6

[PIXELBOX_SRO]

Hello,

i ve encountered this really weird shading issue which seems to be problem on vrays end after all the tests weve done.

please see both sides of the images - dents and banding alongside the objects length.

We tried various modelation changes, different approaches but this always happens no matter what you do with the object.
perhaps its something with triangulation that vray does before rendering , i dont know, but were lost when it comes to finding clues.

I will happily send the scene to support when it gets picked up here,but since its holiday in Bulgaria today, maybe someone else encountered this problem before.

Thanks a lot for help
Regards
Martin

[anthonyh]

The suggestion I see a lot on these forums is to try turning Adaptive render off.
anthonyh

[PIXELBOX_SRO]

Will give that a try thanks

[vlado]

It doesn't seem like it's related to adaptive sampling of anything. We will really have to look at the scene.

Best regards,
Vlado

[PIXELBOX_SRO]

Email with scene sent Vlado.
And you are right, turning of sampling did not do a thing.

[vlado]

So this seems to be some precision issue with the rectangle light because it's very long and thin; will look into it, but in the meantime you can work around it by assigning a white VRayColor texture to your rectangle lights (it will render slightly slower though).

Best regards,
Vlado

[PIXELBOX_SRO]

perfect thnak you!
this is extremely helpful you know...its been troublin my mind whether we are doing somethign wrong….with MAX you never know

[vlado]

Btw any reason you are using the Ward BRDF and not GGX?

Best regards,
Vlado

[PIXELBOX_SRO]

hmmm...i always have GGX on so this is probably a mistake.
is it not doing this with GGX on?

[vlado]

is it not doing this with GGX on?

It's still there (the issue is in the light, not the material), I was just wondering (I was actually comparing what different render engines do with that scene and GGX is portable while Ward is not :P)

Best regards,
Vlado