No UV-Mapping needs stronger warning

[tngreene]

My impression was that all textures had to be UV Wrapped. What I've found is that as long you ever set a texture to have a UV Map once, it doesn't matter if you have coordinates set to UV. Seems wrong.

[bsupnik]

I don't think I understand the problem here. Can you describe the edge-case using very Blender specific language?

A few bits of confusing terminology:

• Textures aren't really UV-mapped -- materials are. Is the issue that you can apply a material with no UV map and the albedo texture slot is still used as "the texture" for X-Plane?
• I assume by UV-wrapped you mean "UV-mapped" - the other term is UV-unwrapped, which is where you let Blender build a UV map that maps the 3-d mesh to a 2-d surface, like unwrapping a present to discover the original flat wrapping paper. Also:
• Do you have an actual object where the exported results are astonishing in some way, e.g. "this actual export isn't WYSIWYG to what I saw in Blender?"
• Do we have any regression comparison (e.g. this was definitely different in the last release)?

Note that I'm slightly hamstrung by my iMac's hard drive eating itself...I won't be able to investigate in detail until I restore the machine (or re-set up my Blender dev environment).

[tngreene]

A warning is okay but it needs stronger wording to describe what could happen (the model looks wrong or weird). It is a severe undefined behavior lookout! kind of message needed. (We found during making the Particle Tutorial .blend file that no UV Map meant shiny monkey and flag for some GPUs and not for others. Since S and T were none, it was the equivalent of a divide by 0 error and some hardware handles it better than others.)