I didn't want my player's blob shadow to look directly down at him, so I put the projector at the same position as the light and used LookAt to make it look more real, but it twitches out. It randomly looks downward.
The player makes particles and has a character controller. I don't know if those would effect any thing, because I'm new to Unity.
I believe your problem is that you have put this in FixedUpdate (). FixedUpdate is framerate independent, as is explained here, and is called at fixed intervals as is defined at Edit > Project Settings > Time > Fixed Timestep. Its main purpose is for physics calculations, and unless it is absolutely necessary, should only ever be used for physics calculations.
In short, your LookAt is twitching because it is running at intervals independent of the framerate. In order to run every frame and in this case, you would instead use Update ().
Hope that helps, Klep
answered Mar 11 '12 at 04:21 AM