View Dependent Modeling

There has been considerable interest in sketch based mesh modeling and editing, from the simple, intuitive interface of Teddy [1], to the more recent techniques to preserve detail in an existing mesh while modifying it with sketched strokes [2]. These approaches apply to editing a single mesh that is consistent in all views, but it is often the case in 2D animation that a character will have a drastically different shape depending on the angle at which it is viewed. View dependent geometry seeks to provide a solution to animating 3D characters with meshes that should deform depending on the viewing angle [3]. With view dependent geometry, a single mesh is represented by several sets of vertex positions specified at different views. Each view corresponds to a point on a sphere, and the mesh vertex positions are interpolated from three key views that form a triangle containing the current view on the surface of the sphere. This project seeks to combine the idea of view dependent geometry with sketch based mesh editing to create an interface for producing 3D characters that might behave more naturally for producing animation that mimics 2D styles. Specifically, focus is given to the problem of resolving multiple, perhaps inconsistent, strokes drawn by a user to deform a mesh from several views. An approach to view dependent geometry that does not require adequate coverage and spacing of key views is also described.