GenDesign CTO and animation director for Shadow of the Colossus and The Last Guardian, Masanobu Tanaka, gave a CEDEC 2021 talk last month on “5 Rules for Animating Giant Characters” he arrived at over the course of both those games.
Mass (01-06 in the video below)
Gravity and Weight (07-12)
Animation Resolution (14-19)
Design / Implementation (20-22)
While able to stop suddenly, large mass is unable to start suddenly, always following a smooth motion curve. Conversely, small mass can come to a sudden stop, a sudden start, and motion curves can break. While generally slow, large mass is not limited in terms of maximum speed.
Gravity and Weight
Gravitational acceleration (vertical axis only) is constant for any object, regardless of size. Determine your weight by referring to creatures of similar size, such as dinosaurs. Weight = Mass x Gravitational acceleration.
Organisms are always moving with optimal energy efficiency. Head and arms at such large masses are heavy so will fall. Muscles become stiff with force so be careful not to overuse overlapping motion.
Simply slowing motion to appear giant will lose detail in the animation. High-frequency detail such as during impacts must be added back in. Ensure you don’t make vibration/reactions too fast.
Design / Implementation
Giant characters can’t be cheated – any glitching will be immediately apparent. Animation system design must involve animators. Use techniques like additive layering to blend in animations without needing to quickly transition between animations.
The presentation is one of the cleanest I’ve ever seen and can be downloaded in PDF form here.