This stuck with me. After some further, more detailed, reading and researching, you can totally create the van der Corput sequence that Hammersly and Halton based extended from in UDK. You'll need DX11 mode on to have it work, as that supports Shader Model 4 and therefore the bitwise operators that make the sequence fairly…
Mathematical construct issues aside, I've never, ever, had a piece of HLSL with a FOR loop work in a UDK custom node. Regardless of if it was fed a constant or variable for number of loops. This pretty well precludes the entire importance sample and gather functions and rather destroys the idea of implementing that in…