Reflections in alpha

[Racso]

Hi all, how do I include reflections in my alpha for composite in Photoshop?

When rendering in VFB my CG object reflects in the ground plane (RGB color) but the reflection is not visible in the actual reflection render element. It seems as if the reflection is not included in the alpha.

My scene has a HDRI environment with a matching backplate as a camera projection. My ground plane got a MtlWrapper (Matte surface, -1 alpha contribution, shadow and affect alpha checked) with a semi reflective VRayMtl in the Base Material slot. In the shading group of the MtlWrapper I’ve connected the camera projection to have the backplate reflect in the CG object.

I hope some whiz kid out there can help me out ☺

I´m using Vray 2.30.01 Maya 2013.

/Oscar

[Zdravko]

Unfortunately this feature is not yet implemented in V-Ray for Maya.
But we are working on it.

[bigbossfr]

Hi,
Use user attribute.
Add an user attributes on the ground (where is the reflection), like : reflectionAlpha=1
Create a extraTex render element, connect a condition node.
On the first color, add a vrayDirt with occlusion mode to reflection.
The second, black color.
First value, add a vray user scalar utility.
In the user scalar, set the variable to : reflectionAlpha, and default value to 0.

You will get an alpha.

[Racso]

Hi, and thank you for your replies. Zdravko, I am really looking forward to when this is implemented in upcoming versions of VRay for Maya and thank you bigbossfr for explaining how to generate a alpha with reflections, I will try it out.

/Oscar