Originally Posted by Zorin

Oh dear...

This is not about the mechanical overlays...

Take the Bf 108 for example. The inner canopy frames, the pitot tube, roof handles, counter weights, spinner, oil cooler struts and tons more are just scattered on the texture map with NO REFERNCE as they are all painted in the base colour of your skin. That is why we need the UVW map to know where they are located.