Monday, September 11, 2006

Improved Lighting and using radiosity in my renders

KoyanFound a really good article in the 4th Issue of Brick Journal about rendering legos, setting good lighting, and correcting colors. There is a great link to Lego Colors, with full include files. There is also a great Tutorial that shows various lighting progressions with POV-Ray on the 5571 Black Cat set (it looks like this was the bulk of what was used for the Brick Journal article). The renders look phenomenal with the switch to radiosity processing, however, they have pushed my render times up from under 30 minutes on a 1280x1024 AA scene, to over 6 hours on a P4-2.8GHz with 2GB of RAM! But the results are pretty impressive. I hope to get one of the new Intel Core Duo processors soon, and hopefully POVRay 3.7 with SMTP is working better there.

Below are some pictures of the difference between using radiosity and the best lighting I could come up with on two tractor models (851 and 8859). Note how, first of all, the more realistic colors look with the new includes, and also how much better the model is lit with the radiosity modes (you don't get dark shadows and specular blinding reflections quite as much, because most of the lighting is coming from a natural ambient radiosity light). New mode is on the left. Render times (for a 1280x1024 AA scene) went from around 25 minutes the old way to around 1:15 with tweeked radiosity (no HDR) "fast" settings. I can get it to look just a little better (although that is a bit subjective on different models) if I crank it up to the 2 pass hi quality, but that was taking over 6 hours per render. I also spent more time on the POVRay code and managed to get a better way to set the camera angle and use the clock to rotate through 4 different angles (45, 135, 225, 315) around a central focal point that is NOT on the origin (vector math actually comes in handy!!). Anyway, I'm playing with some other things, like adding barns and lego "fence posts" to the scene, and played around with some grass include files, but when you get too much grass patch in the scene, I end up blowing up even my 2GB render space...grin...and that is with VERY sparse grass and a very limited patch. Makes sense, once you start exponentially increasing the blade counts (at one point I was up over 2.5 billion tokens rendered in the scene...I don't know where it was when it failed).
New radiosity and old renders
New radiosity and old renders

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