HI. I can help you regarding your problem why nothing model scene during exporting 3d. Well, you need to GROUP or make COMPONENTS of all your materials (like Walls, Tables, Door, etc.) in sketchup before Exporting to 3d. as a result, all which GROUPED materials (like Walls, Tables, Door, etc.) are only be exported to 3D, which is ".dae" files. IF you DON'T GROUP OF MAKE COMPONENTS, there will be nothing to do with exporting.

sorry for my bad english..
Greetings from PH.