I have a project where I reuse the same material for multiple things. So, I use node groups; saves a lot of trouble - at first!

Up to this problem I have with node groups:

In 1 you can see, that the logo (white text) is on a black background. This black background should be a node group (and certainly not black).

The black should be colored (or a material from a node group)

Here is the Logo Overlay node group:

Logo Overlay Node Group

If I put the node group "ultramarinblau" into the Logo Overlay node group, it does not work!

Only if I add the "ultramarinblau"-node group directly into the Logo Overlay node group, it works:

Logo Overlay Node Group with Node Group included

This behavior is not desired. I'd like to reuse my Logo Overlay node group multiple times with a different node group-input.

What am I doing wrong? Or could this be a limitation of Cycles node groups?

Any ideas are appreciated!


This is because you are plugging a Shader output (green) into a color input (yellow). See What is the meaning of the color of the node sockets in the node editor?

Instead you should add a shader input (green) to the "Logo Overlay" group. Doing this is a little complicated, as you currently can't directly set the socket type without some python. However, it is possible:

  1. Enter the node group (↹ Tab)

  2. Plug the placeholder output of the Group Input node (hollow) into any input socket of the desired type. In this case, green for shader:

    enter image description here

    Optionally rename the new input in the properties panel (N).

Once this is done, your setup should work.

I don't recommend putting the material output node inside a node group, as this could lead to confusion down the road depending on how the group is used. Instead you might want to plug the mix shader into a Group Output node, and plug the entire group node into the material output in the main node tree.

  • $\begingroup$ Ok, I think I understand what you mean. But, how would I change the imput type to shader? Even if I connect the third input directly to my Mix Shader (from Logo Overlay), it does not change color (of the group input node). $\endgroup$ – gilu Jul 29 '15 at 6:42
  • 2
    $\begingroup$ @gilu Once the socket is created it's type can't be changed. You'll have to create a new socket by connecting the blank output (bottom). Then you can delete any unneeded sockets in the properties panel (N). $\endgroup$ – gandalf3 Jul 29 '15 at 6:48
  • $\begingroup$ Bingo! I had to remove the node and reconnect it! Thanks, gandalf3! $\endgroup$ – gilu Jul 29 '15 at 6:49
  • $\begingroup$ You're right, I removed the output node from the group as well. This adds more flexibility as well. Since displacement can now be controlled outside the logo group. $\endgroup$ – gilu Jul 29 '15 at 7:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.