Cornell University Program of Computer Graphics
A sketch-based interface for parametric character modeling.Nasheet Zaman.
Master's thesis, Cornell University, Jan 2007.
We present an innovative modeling technique that allows artists to freely sketch changes to a realistically proportioned face mesh. Our concept builds a sketch-based interface over a parameterized, topologically optimized, rigged, textured, ready-to-animate prototype face model. Parametric modeling and sketch-based mesh editing are two previously disjoint areas of research we have merged to develop a unique system. The first component is the parametric setup. The prototype is marked with selectable anthropometric landmarks, which can be moved to locally reshape the geometry. As the user changes the positions of landmarks, facial measurements are recorded internally. Anatomical limits are calculated based on demographic data and figure drawing conventions. These limits may be visualized interactively to guide realistic modeling, or ignored by the artist for more stylized creations. The second component is the sketch-based interface, which streamlines the process of moving landmarks and reshaping the mesh. Using a tablet and stylus, the user first sketches a selection curve through some landmarks, and then sketches a second curve describing the desired shape of the region defined by the selected landmarks. The corresponding region of the mesh is automatically morphed in 3D space to conform to the new curve. During this process, the user can continue to use the parametric visualization mechanisms to maintain or exaggerate proportions. Thus, the artist can enjoy the freedom and simplicity of drawing to quickly design and generate a vast range of complex and original characters, using just one simple, intuitive, and familiar tool.
This paper is available as a PDF file Zam07.pdf (5.9M).