is there a way to make a material, in Blender Internal, that makes the outside faces of a mesh invisible, but the inner faces visible?
Turn on backface culling (turned on by default) and flip the normals of the mesh.
flip the normals
Thanks for the answers
backface culling only works in the editor not in render, but i found the way to do it, if anyone want to know, what I did was flip the normals, then I added a geometry node and connected front/back to the alpha of the output and in render pipeline options turned on the transparency