Matte issue with Vray Standalone and Render farms.

[Robert]

I have an issue with Matte rendering and external rendering via Renderfarm. So in my case I used the reflection option in the matte settings to reflect the environment texture (camera projection in the environment for reflection). Now that all works perfect fine in Modo, both RT and final render. But once I send it to a farm I get a shadow catching surface without the reflections. Tested two farm and standalone, always same result. How can investigate that?

[vladimir.nedev]

You tested with the "Render with V-Ray Standalone" command and had the same issue ?

We need a scene to investigate.

Greetings,
Vladimir Nedev

[Robert]

I don't get it anymore in Standalone, just on Chaos Cloud and another farm. I went further testing, I have to get that shot rendered first, till I do debugging.

But what I found strange is that I get a reflection in specular channel, but not only in that case. Is that something new? Looks like its only the first bounce reflection.

[Robert]

The specular thing is just the environment. Have that in other project since latest V-Ray 4.x to (I didn't do an update since April).
Also I see that Lightcache samples produce flickering in a glossy reflection pass. I didn't had that before and seems only to happen if I render the reflection shader only. Remember me to a bug with the alsurface material

[vladimir.nedev]

The specular thing is just the environment. Have that in other project since latest V-Ray 4.x to (I didn't do an update since April).

Yes, in V-Ray 4.x the behavior of the specular and reflection render elements has changed, when it comes to reflections from lights.
The specular render element now includes the full light reflections (including dome light from env. imp. sampling).
Previously the light reflections were split between the specular and reflection elements, based on sampling.

This brings V-Ray in line with other popular renderers.

You can get the old behavior by disabling the "consistent lighting elements" option from V-Ray Main -> Global Options - advanced.
However, if you have "Adaptive" enabled for a dome light, the "consistent lighting elements" will get automatically enabled internally,
as they required for the operation of the adaptive dome light.

Greetings,
Vladimir Nedev

[Robert]

ok, got that. Yeah it makes denoising also easier.. thinks for the explanation.

[Robert]

Seems the problems getting worse. Send mail to Boyan.. you have some wired stuff going on in reflection output.

It seems the problem comes from a shadow catcher/mate object, that automatically react to the environment background. So the light coming through the shadow catcher from an HDRI don't get sampled at all and leave artifacts on the reflection channel. I also have a scene where all channels being affected. The only work around I found is turning off reflections in the shader option of the matte object.