Need shadow catcher advice

Can someone look at this screen shot and tell me what I’m doing wrong?

I have a circular disc under my objects and the material (grey floor) is applied to it. I then select grey floor in the base material slot of the wrapper material, check matte and shadows. But my grey floor doesn’t become transparent and I have no shadows.

Thanks in advance for your advice.

There is a material in the library called Matte Shadow Receiver normally just use that:


The other thing to check for is a visible dome light. The wrapper material doesn’t support matte with a visible dome light.

Thanks for the reply.

Fortunately I have Thea which handles things like this in a very direct way - call up Rhino’s ground plane, apply Thea’s shadow catcher to it, done.

So I switched to Matte_Shadow_Receiver and deleted the dome light but still no success. I seem to get better shadows but no way to increase or decrease them. And no transparency on floor.

Any other thoughts about what I might do?

Also, does your email imply that V-Ray can’t have both a shadow catcher and an hdri at the same time? Whenever possible I light with only a hdri.

Thanks for your input.

@arail you attach the HDRI to the background environment and you can still use an invisible dome light.

Thanks but no luck. Shadow Catcher is applied to the disc below my geometry, no transparency. Dome Light is disabled.
Honestly, I think the Environment, Background panel is a confusing mess.

This is the setup:

And this is what I can get with 3 clicks in Thea. No light set up, no multipliers, just 3 clicks:

I don’t understand why it’s so difficult and confusing in V-Ray 3

I learned something after posting this - V-Ray seems to be sensitive to the history of a scene. What I mean is, I finished the scene and rendered it out in Thea (see above). Then I copied the geometry, dragged it to a new location, turned off the ground plane and swapped out the Thea materials for V-Ray materials. No shadow catcher.

Then I selected the geometry (that had V-Ray materials applied) and copied it into a fresh scene and the shadow catcher worked. Not sure why that would be but there it is.