MV's Cinema 4D Cinema4DXL Version seven introduced new 3D channel shaders, amoung them the 3D rust shader. This shader seems useful because it allows you to speckle an object with a user defined percentage. I was using this shader a lot until I discovered that it doesn't animate well. You will notice in the movie below that as the camera zooms away from the object, the rust quickly attenuates and then completely disappears.