[Suggestion] UV Stretching/Aspect Preview

[TheDudeFromCI]

A feature that would be extremely useful, especially now with the introduction of meshes, would be a preview mode for viewing UV stretching/aspect distortion. When assigning UVs to non-unit-aligned faces, especially on meshes, it's not always clear how badly the texture pixels are distorted. In addition, even with the existing UV Preview mode, it's not always clear how "square" each pixel is on the model.

For example, say I am texturing a roughly 4.5+-0.2 cm tall quad by 8 cm wide. Which height would cause less distortion on the UV editor? 4 pixels tall or 5 pixels tall? In the editor, both options look mostly correct, but which option is better?

As for implementation, it would be pretty straightforward. Just color each face by how closely the UV aspect matches the face's aspect ratio. If both are equal, make the face display white or similar. As the aspect difference increases, the color can shift to a more red color. Likewise, a similar option can be done for pixel density. Given the average pixel density of all faces in the model, faces further away from that value might appear bluer in color.

This option is seen commonly in applications like Blender, and I figured it would make a good fit here. Unfortunately, I haven't found any open issues for this idea, and thus I thought it would be best to create a new suggestion.