I've made a model in sketchup, exported it as .dea to Blender, then exported it again to 3ds through blender. I have now imported it to Unity, where I can't see it at all. Any ideas on why?
Check the models scale to make sure it isn't too small to see when imported in Unity.
have assigned a material? if u use blender,try to export in FBX.
Make sure you've added a MeshRendered component to it also.
I just ran into this same problem, and as far as I can tell it was because I was using Blender 2.5 alpha 2. Been using it to learn all the new stuff. I switched to using blender 2.49 and it worked just fine.
[edit] Also, so far when using blender 2.49 I have had no need to export it as an fbx.
~Kine'Nan