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Does anyone know is there's an automatic way to render shadows on a matte surface that can be independently adjusted in post production?
The method I'm using is to keep Affect Alpha ticked in the VRayObjectProperties > Matte Properties tab, and add an Object ID Multi Matte render element for the shadow catcher / ground plane. In post I mask the main render with an inverted copy of the ground plane Object ID to remove the shadows, and I mask a duplicate of the render with the original ground plane Object ID to isolate the shadows, so their opacity on the backplate can be adjusted. The edge of the Object ID masks often need adjusting to eliminate the small fringe that ocurrs at the transition between the matte surface and the other objects.
It would be great if I could directly generate a separate render element of the just the shadows on the matte surface, without those shadows affecting the main alpha channel. It would be even better if this matte shadow render element could include shaded areas occluded by other objects to eliminate any fringing.
I'm aware that the Raw Shadow render element can be used as a mask on solid black (with opacity adjusted) to create a shadow, but it's usually far too noisy unless Consider for Anti-Aliasing is checked which seems to signifcantly increase the render time.
I'm rendering 16 bit PNG files using the V-Ray Output System, as I need to then perform manual masking / rotoscoping of existing foreground elements in my backplate image/footage in other software.
Any suggestions would be most apreciated.
The method I'm using is to keep Affect Alpha ticked in the VRayObjectProperties > Matte Properties tab, and add an Object ID Multi Matte render element for the shadow catcher / ground plane. In post I mask the main render with an inverted copy of the ground plane Object ID to remove the shadows, and I mask a duplicate of the render with the original ground plane Object ID to isolate the shadows, so their opacity on the backplate can be adjusted. The edge of the Object ID masks often need adjusting to eliminate the small fringe that ocurrs at the transition between the matte surface and the other objects.
It would be great if I could directly generate a separate render element of the just the shadows on the matte surface, without those shadows affecting the main alpha channel. It would be even better if this matte shadow render element could include shaded areas occluded by other objects to eliminate any fringing.
I'm aware that the Raw Shadow render element can be used as a mask on solid black (with opacity adjusted) to create a shadow, but it's usually far too noisy unless Consider for Anti-Aliasing is checked which seems to signifcantly increase the render time.
I'm rendering 16 bit PNG files using the V-Ray Output System, as I need to then perform manual masking / rotoscoping of existing foreground elements in my backplate image/footage in other software.
Any suggestions would be most apreciated.
