I am rendering short animations/fly-thrus and one of them has this scenario - you open the door and enter the apartment, apartment is very dark because shades (roll blinds?) block the light, then shades start going up and more light gets into the room. As soon as they`ll start to move the problem occurs.
http://www.hot.ee/sdaqk/problem.jpg
I use medium - animation preset for irr. map and incremental add to current map.
tnx in advance