Matte compositing reflection elements – known limitations/bugs?

V-Ray V-Ray for 3ds Max Issues
1

Hi all.
This issue is related to getting reflections on matte surfaces in render elements

Simple example scene: background- gray corner, hero- red ball.
All materials have full contribution to alpha, then reflections are rendered to Light elements, and VrayReflection.

The non-matte set up:

elements_fullAlpha.jpg
elements_fullAlpha.jpg2560×512 103 KB

Now If background material is set to be a Matte surface (either via VrayMtlWrapper, or Vray object settings), the full RGB renders correctly, while reflections don’t show up in any of the render elements, hindering compositing options. Like so:

elements_matteBG.jpg
elements_matteBG.jpg2560×512 62.6 KB

This a big problem for compositing, that I’m currently trying to work around. Especially was expecting to have light control in composite.
Matte settings just in case:

matte_settings.jpg
matte_settings.jpg352×280 22.4 KB

Any insight into whether this is expected, or bugs, or I have something wrong in my setup would be much appreciated. Thanks!

2

Hm, I’m uncertain if matte reflections are considered. I’ll do some testing and write back.

3

Turns out it’s a known issue (internal bug-tracker: VMAX-6479). LPEs display the issue as well, unfortunately. Logged it in as well (internal bug-tracker id: VMAX-13218 ). What you can do is use the current Full Light Select (without matte reflections/gi) and extract it from the RGB. This will get you the missing information.

4

Thanks for the update. And thanks for the suggestion, yep that totally works, much appreciated!