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!


1 Answer 1


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, 2015 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, 2015 at 6:48
  • $\begingroup$ Bingo! I had to remove the node and reconnect it! Thanks, gandalf3! $\endgroup$
    – gilu
    Jul 29, 2015 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, 2015 at 7:09

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .