I have some meshes that are parts of hallways with different crossings but all walls have no thickness. For purposes of rendering it in a game I program they need thick walls (for avoiding artifacts with shadow mapping).
How can I achieve this thickness with Blender? My three conditions are
No self intersections: I know about the solidify-modifier but the angles of my mesh make it so, that the new thickness intersects with itself which is not ideal (z-fighting).
UV-coordinates of all pre-existing vertices have to stay the same. We have a cool looking texture and the texture-mapping has to stay the same.
Stay tileable: The meshes get positioned next to each other in order to form a maze. This has to be possible with the thick meshes.
The outward appearance of the mesh is not important since they are only seen from the inside. Additional I should be able to do this within a day for round about 10 meshes.