We're talking about the possibility of recreating a ray tracing utility in PDN, and I just can't see that happening.
It's not just the ray tracing, but the whole 3D modelling environment that need to be reproduced. I did look (briefly) at this, but quickly gave up as it's very daunting indeed!
If you really, really need to model 3D object with accurate lighting I suggest POV or a similar utility.