Hate to bump an old thread but I found that apparently this is another PC port that relied on special hardware for a graphical effect.
According to this forum post: https://forums.geforce.com/default/topic/353473/pc-games/advent-rising
Apparently the shadows only worked on an ATI 9800 Pro card. I have tried enabling the shadow ticks in the config files but I have had no success. Even tried 3DAnalyze with no success to emulate the shadows. If there is a way to get them working or if someone knows how to get a wrapper to work with this game, I would love to know.