Abstract: In this paper, we propose a hybrid method for simulating water droplets on the glass pane. We model the motion of water droplets based on a particle system. The shape of the water droplets is constructed by converting the particles into a height map according to the water amount of the water droplets. To realistically compute the shape of the water droplets, we also consider their movement directions when the height map is computed. We have implemented our system and evaluated its performance. Our system can simulate the water droplets realistically at an interactive rate.