Jump to content

Edmund Liang

Compositing Tag & Sky Object Problem

Recommended Posts

Hi everyone!


I’ve been stunted by this problem and was wondering if anyone else has come across it. Hopefully, I can describe it correctly—attached is a sample scene. Should be able to see the problem as soon as you hit render.



Building with a figure and planters in a patio.



After I've calibrated the camera and set up the planes for objects to cast shadows on (Compositing Tags set w/ Composite Background enabled), I usually put in some lights to light the objects. But I've recently tried using a Sky Object to light my scene. I love how the Sky object lights the objects more realistically. However, the Sky Object causes the planes with the Compositing Tag & Composite Background enabled to...reappear in the render as dark semi-transparent versions of themselves.


The planes with the compositing tag do not appear when I use regular lights though, just Sky Objects it seems. 


Has anyone else encountered this problem?


I’m running on Cinema4D R20 + Mac Mojave.


Thanks so much everyone!



Share this post

Link to post
Share on other sites

the GI lighting in your scene multiplies over the background compositing. the planes become visible, because the GI shadow is visible on them.

the question is what do you want to achieve?


shall the walls emit light on the object?  

shall the object throw shadow on the environment?


This image shows the shadows:



  • Like 1
  • Awesome 2

Share this post

Link to post
Share on other sites

you can work around the issue with some tweaking. see different.zip
some workkaround steps:

- adjust GI Gamma, so lighting is more smooth

- blend of luminance and color channel, to decreae shadows

- adjusting of Matrerial : Illumination : GI Receive and GI throw settings + Saturation option

- adjusting of Material : Color Channel : Texture : Exposure


Of course the best solution would be a low poly reconstruction of the set + a Set HDR or at least some kind of Panorama





  • Awesome 1

Share this post

Link to post
Share on other sites

Thank you SO much for chiming in on this @ChrisSK!!!


Yes to both of your questions up there:

Shall the walls emit light on the object?  

Shall the object throw shadow on the environment?


I'm going to check out your attached C4D files. Off the top, the "different 2.c4d" is closer to the render result I'm going for — where the objects look integrated into the photo/environment. I had no idea that the GI lighting multiplies over the composited background — thank you so much for pointing that out. I kept wondering if it was an error or just some really hidden checkbox I didn't click.

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.



C4D Cafe is the largest CINEMA 4D community. We provide facilities for discussion, showcasing and learning our favorite software :) Register now to gain access to all of our features. Once registered and logged in, you will be able to create topics, post replies to existing threads, get your own private messenger, post status updates, manage your profile and much more. If you need to find solution to your problem or otherwise ask for help, Cafe is the right place.
  • Create New...