PoseTween: Pose-driven Tween Animation

Augmenting human action videos with visual effects often requires professional tools and skills. To make this more accessible by novice users, existing attempts have focused on automatically adding visual effects to faces and hands, or let virtual objects strictly track certain body parts, resulting in rigid-looking effects. We present PoseTween, an interactive system that allows novice users to easily add vivid virtual objects with their movement interacting with a moving subject in an input video. Our key idea is to leverage the motion of the subject to create pose-driven tween animations of virtual objects. With our tool, a user only needs to edit the properties of a virtual object with respect to the subject's movement at keyframes, and the object is associated with certain body parts automatically. The properties of the object at intermediate frames are then determined by both the body movement and the interpolated object keyframe properties, producing natural object movements and interactions with the subject. We design a user interface to facilitate editing of keyframes and previewing animation results. Our user study shows that PoseTween significantly requires less editing time and fewer keyframes than using the traditional tween animation in making pose-driven tween animations for novice users.