Ryan, can you walk through this in a bit more detail? Your last paragraph isn’t making sense to me. The only ‘texture cube’ node I could find is TextureSampleParameterCube. I couldn’t hook the output (ParamCube) to Emissive Color.
I’m in a similar situation to GitRHero. I have an equirectangular panoramic I rendered in Blender of the inside of an icosphere. Can be viewed below:
http://i.imgur.com/0GpwHMS.png
What is the intended way to get this texture into my skybox? Can you show us what the material graph would look like? Does it matter what kind of mesh we use? I had been using SM_SkySphere but it had the UV strangeness that GitRHero described above.