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View Full Version : Global Illumination and "Camera Animation" Mode ?!?


mmalone
11-27-2005, 02:49 PM
According to the manual, when I set Global Illumination (radiosity) to the "Camera Animation" mode, radiosity will only be calculated once thus rendering in a fraction of the time. It doesn't seem to work though. Every frame seems to take the same time to render. I get what looks like shading points being calculated on every frame.

Anyone see a huge decrease in render time using this mode?

I have 9.521 on Mac 10.4.3

thanks for any help

mike

Simon Wicker
11-27-2005, 03:19 PM
the answer is yes but with certain caveats. some people have found that with very long animations the rendering slows down towards the end as the gi cache becomes very large and has to be evaluated fully for each frame. also with fast moving cameras you are revealing new areas of the scene which have to be added to the gi cache and this also takes time.

as you have noticed the shading points are not calculated just on the first frame, they are still evaluated on every frame, however if a shading point already exists in the cache it will not be recalculated (red are new shading points, green are re-used shading points). this is where the speed up comes in.

cheers, simon w.

mmalone
11-27-2005, 06:59 PM
however if a shading point already exists in the cache it will not be recalculated (red are new shading points, green are re-used shading points). this is where the speed up comes in.

I do see a few red dots along the sides as the camera slowly pulls back. I just don't see any speed up from the first frame to all that follow. I'll put a stopwatch to it to make sure.

thanks

mike

Simon Wicker
11-27-2005, 07:58 PM
well the time decrease only occurs during the pre-pass phase - not during the rendering phase. by re-using shading points the pre-pass is calculated faster.

cheers, simon w.

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