Leveraging the talent of hand animators to create three-dimensional animation

The skills required to create compelling three-dimensional animation using computer software are quite different from those required to create compelling hand animation with pencil and paper. The three-dimensional medium has several advantages over the traditional medium---it is easy to relight the scene, render it from different view-points, and add physical simulations. In this work, we propose a method to leverage the talent of traditionally trained hand animators to create three-dimensional animation of human motion, while allowing them to work in the medium that is familiar to them. The input to our algorithm is a set of hand-animated frames. Our key insight is to use motion capture data as a source of domain knowledge and 'lift' the two-dimensional animation to three dimensions, while maintaining the unique style of the input animation. A motion capture clip is projected to two dimensions. First, time alignment is done to match the timing of the hand-drawn frames and then, the limbs are aligned to better match the pose in the hand-drawn frames. Finally the motion is reconstructed in three dimensions. We demonstrate our algorithm on a variety of hand animated motion sequences on different characters, including ballet, a stylized sneaky walk, and a sequence of jumping jacks.