Hello! I was just wondering a way to fix this… I’m trying to design a level in Blender, and when ever I import it into Unity it makes it look odd.
So here is what i did… I stuck with the original box that it gives you… and kept extruding the region (one edged side of my box) so it made sort of a tunnel. I kept doing this until i had a simple level. Everything looks fine in blender… but when i import it into Unity3D and place my character inside the tunnel, I don’t see anything except for the walls. No floor or celling. Now i did “generate colliders” in Unity3d but that still doesn’t seem to help. I can only see the “outside” of my level, not the inside.
Now if i position this above the terrain, I can see the bottom of my level perfectly, the colliders work and everything. But when I’m “inside it” aswell as the floors and cellings missing, some parts of the walls are too (randomly) and there is no collision.
Here is the blender pic ImageShack - Best place for all of your image hosting and image sharing needs
Here is it in Unity underneath (notice everything looks fine and the colliders are fine underneath ImageShack - Best place for all of your image hosting and image sharing needs
And lastly here is it above it, I also fall right through it
http://img822.imageshack.us/img822/5171/unity2.jpg
I also found this video which is actually what inspired me to create the level this way… In the first 6 seconds he does something to his cube that i think makes it so it “flips” the cube, not sure tho. And sense it is time-lapsed i cannot make it out. Maybe someone who actually knows blender can tell me 
http://www.youtube.com/watch?v=B4T07vO2THk
Thanks for any help!! It is very much appreciated!!