matte shadow issue - reflections

[Johan Sundberg]

Hi,

I've already searched plenty of matte shadow threads before posting this. But couldn't find an answer to my problem.

This is my scene:

Dome light with hdri
floor plane (matte object with these settings - matte object checked, matte for refl/refr checked, alpha -1, direct light shadows and affect alpha checked.
object
background image (as enviroment map)
the floor plane (matte object) have a reflective material as I like to capture the reflections showing in the background image, and have my object reflect on the floor plane.

The problem is when using a reflective material on my matte object, it shows up in the render but with a lower opacity (alpha is 0,0,0). Please see the attached image as I cant explain very well.
My question is how do I capture the reflections without seeing the matte object?

[king_max]

Render the GI, Shadows and Reflection passes. What you see is probably the GI on the matte. I don't understand why don't you just composite the render in photoshop? Anyway, if you wish a clean matte/mask of the 3D object and its reflection on the floor, render a MultiMatteElement of all the objects except the floor. In the VrayMtl of the floor object reflection section set "Affect channels" to all channels. Uncheck all the matte parameters in the floor object.

[Svetlozar Draganov]

Would it be possible to attach that scene for investigation?
Let us also know V-Ray and 3dsMax version you are using.