Glossy Fresnel and Opacity Bug

V-Ray V-Ray for Maya Issues
1

Hi,
I found a bug if you use Glossy Fresnel and Opacity in VrayMtl on 2 objects.
Bascially the opacity breaks if you have Glossy Fresnel Turned On and have two objects with fresnel on top of each other.

See example:
To reproduce:

1) create two planes with Glossy Reflection on in VrayMtl
2) Fade the border of one of them with opacity. In my case I erased the borders of the top plane with a ramp.

3) If you put now one plane over the other and render you can see UGLY BORDER if both the planes have Glossy fresnel turned on!!!
4) if you turn off glossy reflection for one of them opacity behaves as expected. If both of the overlaying planes have glossy fresnel turned on the opacity gives crazy border

So, is this is a bug ? or user error ?

thanks

Glossy Reflection breaks with opacity and two objects.jpg
Glossy Reflection breaks with opacity and two objects.jpg1443×779 227 KB

2

Hi, we are aware of that issue and we’re working on it.
Thank you for your feedback.

3

We are looking into it. If you set the IOR of the transparent plane to 1.0, does it render differently?

Best regards,
Vlado

4

If I set the IOR to 1.0 of the plane above or below the nature of the artifact remains the same. :frowning:

5

I can also add that the Lighting, Specular render element is broken if you disable Fresnel and glossy fresnel.
Also Lighting, Specular is broken with the VRayCarPaintMtl.

6

Hi,
the lighting and the specular render elements seem to work fine on my end (3.52.02). Which V-Ray and Maya verison do you use? If possible sharing a scene would also be helpful.