This paper describes a novel model known as the shadow obstacle model to generate a realistic coer-tuing be-havior in crowd simulation. The motivation for this model comes from the observation that people tend to choose a safer route rather than a shorter one when tuing a coer. To calculate a safer route, an optimization method is proposed to generate the coer-tuing rule that maximizes the viewing range for the agents. By combining psychological and physical forces together, a full crowd simulation framework is established to provide a more realistic crowd simulation. We demonstrate that our model produces a more realistic coer-tuing behavior by comparison with real data obtained from the experiments. Finally, we per-form parameter analysis to show the believability of our model through a series of experiments.