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.