I finished my 3d model of a face and I tried to import it into Unity. I dragged in the .blend file and then into the scene. But I could only see the back half of the face from where I was looking. I could also see the whole model from the inside.
Face normals are in wrong direction and unity renders only one side of the face with this shader. Select everything in edit mode then click on mesh>>normals>>recalculate outside or flip normals. If you hit "n" and check in backface culling you will be able to check your model, and the inside of the faces are also darker.