Physics-based animation of a trotting horse in a virtual environment

In this paper we describe the implementation of a physics-based animation of a trotting horse in real-time. The horse is modelled as a collection of connected bodies using the open dynamics engine library to simulate gravity. The animation is created by comparing the current state of the horse with a desired state and applying torques proportionally to the errors present between the two. The desired state is obtained from frames of video footage of a trotting horse. P-controllers are used to minimise the error between current and desired angle positions as well as global positioning and orientation of the horse's trajectory. Results show realistic movement patterns as compared to the video footage and realistic ground reaction force patterns of each individual leg.