Despite the recent success and proliferation of 3D computergenerated
imagery, traditional 2D hand-drawn animation is still a
popular medium for animated films. Even in modern 3D production
pipelines, 2D animation plays an important role during preproduction
(such as in the story, layout, and animatic phases). The key
advantage of the 2D drawing metaphor is that it provides complete
artistic freedom without the restrictions imposed by a CG environment
(e.g., limited flexibility due to the 3D model and its animation