Real-Time Probabilistic Locomotion Synthesis for Uneven Terrain

Abstract: In modern games and animation there is a constant strive for more realistic motion. Today a lot of games use motion matching and blending with lots of post-processing steps to produce animations, but these methods often require huge amounts of motions clips while still having problems with realistic joint weights. Using machine learning for generating motion is a fairly new technique, and is proving to be a viable option due to the lower cost and potentially more realistic results. Probabilistic models could be suitable candidates for solving a problem such as this as the are able to model a wide variety of motions due to their built-in randomness. This thesis examines a few different models which could be used for generating motion for character when interacting with terrain, such as when walking up an incline. The main models examined in this thesis are the MoGlow model and a CVAE model. Firstly virtual scenes are built in Unity based upon loads of motion capture clips containing movements interacting with the terrain. A character is then inserted into the scene and the animation clips are played. Data is exported consisting of the character’s joint positions and rotations in relation to the surrounding terrain. This data is then used to train the models using supervised learning. Evaluation of this is done by having character go through an obstacles course of varying terrains, generating motion from the different models. After this foot sliding was measured as well as frame-rates. This was also compared to values from that of a selection of motion capture clips. In addition to this a user study is conducted where the users are asked to rate the quality of generated motion in certain video clips. The results show that both the MoGlow and CVAE models produced movement resembling real human movement on uneven terrain, with the MoGlow model’s results being most similar to that of a the motion capture training data. These were also found to be executable at interactive frame-rates, making them suitable for use in video games.