I need Shadowcatcher working over Objects (not only HDRI) - please help

[BeneZ]

Hello,

why does shadow catcher not work over objects? Is there a workaround?

I have objects of selfillumination (they are reference images an represent a projected scene) and now I need shadow over them.
I need to see this live in the IPR and not only after composing.

I tried MaterialWrapper, ShadowCatcher with Alpha -1 and even Vray LightMaterial was not working (in hope it is treated in the same way as the HDR).

Attached screenshots, it's currently not possible to have self-illumination with shadow, but this is needed in movie projection workflows.

Test with MaterialWrapper:



with a diffuse I see of course the shadow, but this is nothing else than a standard material



shadow catcher works only on HDR, as soon as I put anything between, image gets black

[vladimir_krastev]

Hi, thanks for posting.Why do you need the VRayOverrideMtl? Try to use the light material in the VRayMtlWrapper's base material. Also by looking at your example it seem that even a simple VRayShadows render element could work if you add it in post .

[hermit.crab]

Not sure if you can do this in one pass at this point. Just to make it clear, it's not a matter of being an HDR or not, it's a matter of being the Background (mattes always show the Background). What you can try is render the scene without the objects, which will do the shadowcasting, as a Spherical projection, which you can later set as an Environment Background or better yet a finite VRayDomeLight.

[BeneZ]

Thanks, it’s not working with a Lighmaterial in MaterialWrapper, I had already tested this.
it‘s an animation scene, I need it definetely to work on OBJECTS.
(Also Renderelements are only an alpha for compositing and no help for me)

Please make shadow catcher work as a „layer“ on whatever there is behind, give it a switch „consider as background whatever is there behind“. This must be a cheap implementation.

The process of rendering out, then checking in Nuke, going back to render out again etc. is tedious.
Backgrounds are in a 2.5D production more than only HDRI.
I asked this already some years ago, this isn‘t anything brandnew or special, especially since many are meanwhile working with simple photogrammetry (without shader just reprensenting illuminated scene objects).
I would need otherwise a live compositing in the IPR.