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I'm getting this error when I try to bake textures on my model. It says "Circular reference in texture stack". I found some info on the net. It says I should disable a texture in the texture stack so Blender won't write the texture on itself. But I don't have any textures in the texture stack. I only have simple materials, no image textures. I'm using Blender Internal, 2.75a. So what should I do to bake the materials into textures? I'm attaching 2 screenshots. The texture is rendered partially, I don't know why. There should be more green and also white (there are two materials on the object, green and white), but it stopped halfway. Also note: I did make an empty image for each UV I unwrapped, before baking.

Screenshot 1:

enter image description here

Screenshot 2:

http://imgur.com/bAVLm5F

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  • $\begingroup$ Is it possible that one of your mesh faces has n-gons? It means unconnected vertices are along an edge. These often cause this error... $\endgroup$
    – user24116
    Commented Apr 27, 2016 at 16:17
  • $\begingroup$ Are you using blender internal or cycles engine? Either way, I assume you want to bake the result for the model into the same texture. If so, you don't need to create several empty textures but just one that has to be assigned to the material. $\endgroup$
    – metaphor_set
    Commented Apr 27, 2016 at 19:52
  • $\begingroup$ I think he uses Blender Render engine $\endgroup$
    – mqbaka mqbaka
    Commented Aug 5, 2021 at 6:22

3 Answers 3

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One example when this occurs is when the receiving image is used as a texture e.g. (has been unchecked) the issue can be reproduced by checking the enable/disable checkbox.

enter image description here

Either way baking worked

enter image description here

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    $\begingroup$ But how do you select the "receiving image"? $\endgroup$
    – Thomas
    Commented Oct 30, 2018 at 3:27
  • $\begingroup$ @Thomas it has been bugging me for a long time untill I saw this youtube.com/watch?v=HiASMYoZ9Sg $\endgroup$
    – mqbaka mqbaka
    Commented Jan 26, 2022 at 7:46
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This problem have been bugging me for as long as I remember. The reason is simple : that error occurs when Blender is told to bake a texture on an image that is already used as a texture hence the term 'circular reference'. It's like trying to film a monitor that shows the footage from the camera you are filming with (I don't know if you understand that :D ). Basically what happens is that Blender 'reads' the data from all the image textures that are used by the material and composites the output into your 'output' image and this error occur when your 'output' image is one of the image textures of the material.

Now the problem is "How to choose this 'output' image", right? Because sometimes, Blender 'seems' to choose kinda randomly the output image to one of your images textures and you have no idea about how to change it. So here is how I do to make sure that I select the image I want for the baking output :

In Blender (the Blender Render engine), we have what we call 'face textures' and the image that is selected as a face texture is the one that will be choosen for the baking output.enter image description here In this simple scence, there is a plane with an image texture applied, you can see the texture by selecting 'material' or 'texture shading mode'. The texture you see is NOT the face texture I am talking about, to see the face texture, select 'SOLID SHADING MODE' and go to the 'N' panel to the 'shading' section and check 'textured solid' : enter image description here Make sure you are in solid shading mode before doing this, otherwise you won't see the 'textured solid' option. For now my plane has no face texture applied and that is why it is shown bright white in the viewport. if I try to bake anything at this point, Blender will choose my image texture as an output by default and I would get that 'circular reference' error.

Now, split your window and change the second window to an image/uv editor if you haven't already. If you switch to edit mode now, Blender will open automatically the face texture of the selected faces in the uv/image editor on the left. If you have no face textures yet, the uv/image editor will still remain empty with nothing but the UV layout of your object.enter image description here If you go to the uv/image editor and chose an image to display, Blender will apply this image as a texture to your object (You need to stay in edit mode). This is how you chose a face texture ( and the baking output). enter image description here If you want a blank image for baking, just add a new image from here (without leaving edit mode) and you should see your new image applied as a texture on your object. Note that this operation will have no effect on your renders since you didn't touch your material textures and you should still be able to see you material textures in 'material shading mode'.enter image description here After doing that, Blender will use that face texture as an output for the baking process, so if the image you chose is not used anywhere in your materials, it should not emit an error.

Sorry for the very long answer but I hope it helps someone.

Someone on Blender artists posted a link to a tutorial that explains face textures in details and this tutorial is the one that helped me solve this problem. A link to it : An awesome tutorial

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For me it was the opposite.

With the receiving texture enabled (box checked) I received a 'Circular Reference in Texture Stack' error.

Without the receiving texture enabled (box unchecked) I received no such error and the bake completed successfully.

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