Hi Motoko,
I was reading this thread hoping to find answers to some of my mesh house building problems. Your mention of SketcUp caught my attention because I am a SketchUp user and then I export it a DAE for Blender to create AO and Texture maps in Blender. If you don't mind I would like to seek your advise or tips in making mesh houses in SketchUp.
1. I have a problem in uploading the finished house in Second Life wherein the Texture maps and the AO maps doesn't show inworld when I export the house I created from SketchUp from Blender with the baked textures and AO. The house is all gray and some faces are scattered around even though I ticked the "include textures" when uploading.
2. My avatar cannot enter the house when uploaded it. It's like as if the mesh house is a solid block even though there's an opened door on it.
How can I upload a finished mesh house I created from SketchUp then exported as DAE for Blender to bake the AO and texture maps then exported as DAE to be uploaded for Second Life? Help!