Stylish Silheouette?!

I brought Oogami demo disk back from Tokyo Game Show 2005. After I tried it, I had to say I really admired Japan's talent of game producing. Especially that chinese drawing-like rendering effect, how did they do that? I tried to look for such information but I couldnt find any useful one. Somehow I heard it used a way to change the texture of the silheouette depending on the camera's position. I didnt know its true or not, so I made a small demo to see how it worked. The result are the pictures above. I used several kinds of textures to replace the silheouette. The result seemed ok...But if i want to do the chinese drawing-like rendering, how do I change textures base on camera position?_?; Oogami's Chinese drawing-like rendering effect, if anyone knows how to do it, please let me know~~ @_@;