Thought at first, Solo made it all in pure sketchup,I was dumbfounded til I read further.
But really, hats off to Solo for that perfect UV job.
Cloth modifiers in 3ds max and similar tools in blender does it so well and even animate it perfectly. That is letting the computer do the artistry and spare yourself from such tedious repetitive work (speed depends on ram though).
I wonder if its ever possible to make a plugin like this directly in sketchup in the current or in the future releases...