Expressive Animation Retiming from Impulse-Based Gestures

We present a method for retiming existing 3D animations able to handle seamlessly arbitrary impulse-like user gestures, thus enabling expressive video-based control inspired from common review sessions used in animation studios. The approach works in recording two videos with fast, impulse-based, gestures: one synchronized with the existing 3D animation and another featuring a new time sequence. We then propose an automatic generation of a modified 3D animation retimed to match the sequences of the second video. To this end, we introduce a robust and automatic method relying on Dynamic Time Warping able to compute the sequential correspondence between the timings of the impulse gestures. The method can adapt to various individual gestures without requiring dedicated learning, and can take into account the semantic integrity of the original 3D animation after retiming.