Cars and GI....

[brian80]

I'm going to make an animation of a camera rotating around building.
I've also a street around this building where I animated few cars.
Since I'm going to do a precalculation of the GI I've a problem with the GI of the cars.
They leave a "black hole" on the asphalt due to the shadow they trace in each 5th frame I calculate the GI, and also on the body of the cars I've some kind of flickering problem, probably always to the wrong GI.
How can I solve this problem?
I tried to exclude cars and street from the GI calculation and added some self-illumination but it's not the same result.

Anybody solved this problem?
Thanks and sorry for my bad english.

[trixian]

You have to separate the cars from the rest.
Render out everything you can consider static geometry in a pass (or several if you wish) using the saved imap procedure. Then render the cars (or all animated objects) against the ground making the ground a matte object....and any other objects the car's reflections and shadows might interact with during your animation should be made intomatte objects as well.
This should solve your problem, but there is a thread here where Tom Schuelke describes this procedure more in detail for a scene he rendered.
Do a quick search for it