Er, uhm...Humus is a coder for ATi now, they'll be using this technique with developers to improve ATi's performance. The reason it doesn't help performance for the nVidia cards is because of the way they handle stencil operations in the pipeline. There is a good explanation of it in the thread at Beyond3D. (Around page 7 I think) This is a real technique that really does do the same thing as dynamic branching, but apparently a bit quicker and in SM2.0. :) Nice one Humus, you never cease to amaze me.