Broken: 2.79 master
Short description of error
UV editor Draw Other Objects stops working when not viewing cycles material texture in UV editor. If you add an image texture in a cycles material you see it in the texture view. However if you click the X to unlink the texture in the image view (to see the objects UV maps without a distracting texture) Draw Other Objects stops working. The objects are sharing the same material. Note that if you don't have an image texture node you can see both UV maps at the same time when not viewing a texture in the UV editor.
There's a Filter setting for Draw Other Objects but even setting it to All does not show the other objects' UVs. It does not show other objects' UVs when viewing other images either.
So to summarize Draw Other Objects does work when viewing the texture that the material uses, but doesn't work when the image is unlinked from the image editor. When working with UVs of several objects (for example to fit them in the same UV space without overlapping) you would like to avoid getting distracted by a texture there, an empty image (which you get from unlinking the texture in the image editor) works way better for viewing several UV maps at once, however right now it doesn't work. In Blender Internal it does work.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps
- Create a new .blend file.
- Add a UV Sphere with Generate UVs ticked.
- Add an ico sphere with Generate UVs ticked.
- Create a new material.
- Assign both objects to the material.
- In the UV editor add a new Color Grid texture.
- In the UV editor tick Draw Other Objects.
- Select both of the objects and enter edit mode. Confirm that you see both UV maps in the UV editor.
- In the node editor add an Image Texture node and set it to use the Color Grid texture.
- Select both of the objects and enter edit mode. Note that you no longer see both UV maps in the UV editor.
- Set the UV editor to use the Color Grid texture.
- Select both of the objects and enter edit mode. Confirm that you again see both UV maps in the UV editor.
- Unlink the image and repeat the above, you don't see both UV maps.