Hierarchical Motion Brushes for Animation Instancing

Our work on “motion brushes” provides a new workflow for the creation and reuse of 3D animation with a focus on stylized movement and depiction.

Conceptually, motion brushes expand existing brush models by incorporating hierarchies of 3D animated content including geometry, appearance information, and motion data as corebrushprimitivesthatareinstantiatedusingapaintinginterface. Because motion brushes can encompass all the richness of detail and movement offered by animation software, they accommodate complex, varied effects that are not easily created by other means. Tosupportreuseandprovideaneffectivemeansformanagingcomplexity, weproposeahierarchicalrepresentationthatallowssimple brushes to be combined into more complex ones. Our system providesstroke-basedcontrolovermotion-brushparameters,including toolstoeffectivelymanagethetemporalnatureofthemotionbrush instances. We demonstrate the flexibility and richness of our system with motion brushes for splashing rain, footsteps appearing in the snow, and stylized visual effects.