Ok, so here is an exterior night rendering I did (with a little post process) which I think looks alright. Definitely could use some work. But what I am trying to do is give it a real sketchy feel. It seems rather difficult to do this when transparency exists in the rendering. Sketch lines will not follow contours 'inside' of the model. This is also a problem with Piranesi as it does not recognize when an object is transparent or not (I don't know how it could).
So, that being said, does anyone have any suggestions on how to achieve a sketchy look for an exterior night rendering?
I'll post another image after this one to show a day time rendering of what I'm looking for.
RA 2012 x64, Piranesi 6 Pro, Sketchup 8, Windows 7 Pro x64, Intel Core i7, 10GB RAM, ATI Radeon Mobile 5870