if this were that simple I'd have had all of my design work as maps by like 2006.
you can import the shapes, but the textures won't load; you need to go through an accessory 3d program like milkshape and add all of them again yourself, but milkshape doesn't take kindly to .dts sketchup files
that said, I wish you the best of luck and if you figure out how, please tell me. I've made a lot of sketchup models over the years that would make great maps or weapons, and can make quite a few more.