Planning tracking motions for an intelligent virtual camera

We consider the problem of automatically generating viewpoint motions for a virtual camera tracking a moving target. Given the target´s trajectory, we plan the motion of a camera to maintain visibility with the target while optimizing certain camera-specific criteria, such as preferred view angle or view distance. Previous work has shown that optimal paths for this problem can be found with a dynamic programming approach. However efficiency for this type of approach, even with a simplified view model, is not good enough for interactive applications. We propose an approach that searches for a collision-free path satisfying visibility constraints in the relative configuration space between the moving target and the tracking camera The search is conducted in a best-first fashion according to time and other optimization criteria. We have implemented this algorithm in a software package that is capable of generating such a tracking motion in fractions of a second. This software module is part of a virtual presence system that generates customizable guided tours to assist users in navigating a virtual scene