Software for creating, modifying and animating digital 3D shapes is a key component in many computer applications: computer aided design, engineering, computer animation and digital games to name a few. This proposal addresses research into dynamic hierarchical part hierarchies, which combine the interrelated topics of modeling and animating digital shapes into a coherent whole, as well as simple and effective sketch-based computer tools, with the ultimate goal of making these tasks more accessible to amateurs and professionals alike. Advances in consumer computer graphics, as well as the current inþux of user generated digital content, both in virtual 3D worlds as well as on the Internet, illustrate the demand for easy-to-use 3D content creation software. Recent research in shape modeling and animation, as well as sketch-based interfaces, has led to the development of experimental techniques, which clearly demonstrate their viability. Yet, most of these are highly specialized and domain specific, and they do not deal with these problems as a whole. The proposed research will build upon this previous work, but put an emphasis on developing new sketch-based interfaces, algorithms and shape representations that allow combining previously disjoint, yet intrinsically connected tasks of shape modeling and animation.