In today’s tutorial we’ll break the laws of physics, and prove we can abuse nodes to make Cycles do anything we want
I posted about this effect on Twitter some time ago as a “useless experiment”. People were interested in it, so I’ve gone back to look deeper into it. The trick is fairly simple: make an object look like it’s being lit from the opposite side using only a Cycles material.
As you can see, there’s only one light in the scene, a Sun lamp. You can actually make the light come from any direction, since it’s controlled by a normal node.