Unfortunately, I’ve only ever used external programs like crazy bump and xNormal to take my greyscale sim flipbook and generate a normal map from that. It can work in a pinch, with no extensive steps to put it together.
Yeah I’ve done the same, but I think the results are often ok at best due to rhe issues mentioned.
Edit: No longer on the phone so, further explained:
Not necessarily saying that’s due to the normal map generation technique. I tend to think normalmapped particles in general offer very little lightingwise over non normalmapped. It is facing the camera after all so it will never do that much. Also, smoke would probably be better suited by tesselation since the “normaldifferences” usually represents a much larger change than a bolt or a rivet, for which normalmaps work great.
I just think it looks unnatural. If you are going to do light rigs, go whole hog and use the gnomonlight setup Anders Egleus presented at Siggraph. It looks a lot cooler than normalmaps.
Thank you for all the help! I’ve managed to get some halfway decent lighting using the light rig normal map method, but I’m still not entirely satisfied. (I’ve also been distracted with other projects…) I’d love to see the Siggraph presentation you mentioned!