"Motion Capture Envelopes: An Investigation into Real-time Modification of Motion Capture Data in a Game Environment"

Supervised by S.Maddock

Abstract

Motion capture data is used widely throughout the games industry to enable human characters to take on a realistic appearance and action. The sequences used to animate the characters are large and expensive to produce, which limits the amount that can be used within a single game. This study aims to remove these limitations by allowing these existing motion capture sequences to be modified, in real-time, to allow the game characters more freedom of movement.

The study bases its research on the example of a goalkeeper performing a save, and aims to prove the existence of a catch envelope – an area of possible points that the goalkeeper can reach, and hence convincingly catch the ball. The study bases its research on two sequences, each of which has only a single point in the sequence where the ball can be caught. By merging the two sequences using varying degrees of dominance, any point between these two original points can be reached by the goalkeeper, hence satisfying the definition of an envelope.

The study begins by showing that merging mocap sequences is possible, and provides realistic results. It then moves on to show that the technique can be used within a game environment, by showing that the goalkeeper can automatically select the best merge factor to reach a specified ball position. Finally, it shows that the technique does in fact provide a significant amount of new sequences from just two original ones, proving the concept of a catch envelope. The study concludes that the technique is a success, and currently the best method for mocap modification that can be used in real-time. Future research is recommended, with exciting possibilities.