No Viewer Node for Shader Node Tree?

Hello everyone,

I rarely ask questions here, but when I do, it uses to be tricky :joy:

I’ve never managed to find any good way to previsualize a node output in the node shader tree. In the compositing, it’s very easy with Viewer Output and Backdrop, but what about shader nodes ?

Let’s say I want to visualize a Noise Texture Node output.
Usually, the only solution for me is to temporary output the node on a plane with a Emission Shader, like so :

But today I’m stuck, because I’m working in the Shader Node Tree of a Spot Lamp.
I’m working on masking a spot light, like so :

On the image above I’m using a PNG texture, but let’s say I want to do it fully procedural with some noise textures, etc… How to previsualize the noise texture ? Because here is the tricky part : we are not dealing with a Material .

It’s only related to Spot Object Data. As you can see, even if I’m in the Node Tree Window, there is no Material name.

It means this Tree is not usable on any temporary “Plane” for visualisation. It’s only Spot Light Data related.

Any Idea how to resolve this ?


Node wrangler, value node connected to the strength socket on the viewer node it adds

make sure you have node wrangler addon enabled in the preferences
And then CTRL + SHIFT + CLICK on any node to preview it.

Node wrangler is one of those addons that are there when you download blender but it is not enabled by default. In my opinion there are no reasons to keep it disabled

Thank’s @jerzygorskiart and @JA12 for your answer.

But where are you expecting to see the preview ? As I said I’m working on a Spot Light, not a Mesh.
CTRL + SHIFT + CLICK is nothing more than adding a Emission Shader on the current object. Here I’m dealing with a Spot Light, do you get the problem ? :slight_smile:

just create a box or a plane with same nodes and when you are done copy it to the lamp nodes

Yes. Either view it on the geometry the lamp illuminates or use a mesh

Ok thanks to both of you for your ideas :slight_smile:

In fact I was hoping to find a real “viewer node like” solution.
Maybe one day, a “real” Viewer Node will be released.

Finally, I came to this solution :

  • I do a linked duplication of the lamp (ALT+D), and move it to another layer
  • I move to this layer to view the texture on an illuminated plane, without being affected by the rest of the scene, and to tune it
  • As it’s linked, the shader node data is up to date on the original lamp

If anybody else find a better solution, it’s welcome :slight_smile:

See you ++