The Choreograph tool helps make Ubisoft's games more immersive.
Ubisoft La Forge showed how its Choreograph tool helped create more realistic animations in Far Cry 6 through an AI-driven motion matching technique.
"Motion matching is a way for the animation system to pick and choose the best animations to play based not only on the input variables, but also on how characters are currently positioned, and how they are expected to be animated next," explained Engine Programmer Raphael Saint-Pierre.
This makes the result look more natural and yields smoother transitions than a state-driven blending system. For example, when a character goes from a walk to a jog, a programmer just needs to change the requested speed, "and the motion-matching system figures out by itself that it first needs a walking animation, then an acceleration animation, and finally a jogging animation, and switches from one to the other at the most appropriate time." According to the developers, the system simplifies decision-making and blending systems.
A motion-matching engine understands the movement created by motion capture and performance capture and allows it to extract "interesting, reusable sequences that can be reordered and stitched into a pattern that may or may not have existed at capture time."
"Performance capture is necessary to provide the game with its unique signature in terms of how characters interact with the world," added Development Director Olivier Pomarez. "As you add more animations, the animation trees become very large and complex. Motion matching helps to organize and blend all that data together to create a seamless motion in an efficient way that doesn’t require actors to account for every one of potentially thousands of different motions."
As for the approach's usefulness for game development, the specialists say that Choreograph relaxes some of the restrictions of MOCAP data, and gives them more situational variety, more control over what gets used and what does not. It picks very short animation sequences making the data more versatile, which allows for better reactivity to unpredictable input.
Choreograph has not been shipped widely yet, but it has already introduced some new experiences to players, like a third-person camera mode for Far Cry 6. Saint-Pierre believes the tool offers more expressive and immersive animations and "frees up human time for a more polished result, as well as processing power for other systems."
Choreograph may be AI-based but it still needs some help from fellow humans: for instance, they need to define what kind of motion they want to be matched, so the gameplay code, animation data, and Choreograph have to be connected to produce a good result.
Ubisoft is not the only studio working on something like that: Saint-Pierre thinks the research presented by the team at GDC 2016 inspired other game developers, including EA, which has revealed that it's working on its own animation systems.