Tag composting issue?

[masterzone]

Usually when I create an interiors rendering I put a simple panel outside the scene with Light Material. To avoid to make shadows into the room I put a compositing Tag onto it but, see what happens on Corona 10 instead of Corona 9 where the functionality works fine...

EDIT: I noticed that if I uncheck "emit light" into the light material the shadow are deactivated without using the TAG...some behaviour are chanced I think...🧐

[bnji]

Hi @masterzone.
Thanks a lot for bringing this to our attention.
Are you able to share your scene project with us?
(please include all necessary assets)
This way, we can investigate a bit further your file's overall scene setup.
Looking forward to hearing from you.
Kind regards.

[masterzone]

sure Benjamin, here attached you can find a simple scene.

1) start the IR
2) go to Composting Tag settings
3) toggle "cast shadows"

You will be able your self that lights stop to emit...
I remember that works fine with previously corona render...

OS: Sonoma
C4D: latest release
Corona: latest release

[bnji]

Hi @masterzone

I'm sorry for the late reply.
After looking at your test scene and understanding your workflow, here are my findings:
-For cases like this one, where you want to use a backplate (plane + a Corona light material) to mimic a background outdoors, you're correct by choosing to use a light material that will be applied to the plane object; however, I'll suggest disabling the "emit light" checkbox from the Corona light material instead of disabling the "cast shadows" checkbox from the Corona compositing tag.
I'm including a modified version of your scene file so you can test it and experiment with it.
I hope this helps.
Looking forward to hearing from you.
Kind regards.

[masterzone]

thanks so much, may some internal engine behavior where changed into the corona 10. Thanks for your tips I will return to use the light material with emit light turned off.

I also noticed the tone map control shader into the light material...and I take a look to the online help to see what kind of shader it is...believe me, the ton map control is a personal request feature that was in my dream from the first commercial release of corona render!!!! I never used it before! thanks!!!!!!!