Epipolar Methods for Multi-View Sketching .

Abstract

Single view sketch-based modelers like SKETCH and Teddy can be powerful tools, but sometimes their inferences are inadequate: in Teddy, for example, if one draws an animal shape, the centerline of the tail will always lie in a plane rather than being curved in 3D. In these cases, multiple-view sketching seems like a reasonable solution: a single sketch gets viewed from a new direction, in which further sketching modifies the shape in a way that's consistent with the original sketch. This paper describes a testbed implementation of such a multi-view sketching approach, based on epipolar lines, which is used for multi-view editing of the "backbone" lines for generalized cylinders. The method works well on many objects, particularly those where precise geometry is not important, but general shape and form must be richer than those with planar symmetry, but is difficult to use in other cases; some difficulties may be related to implementation choices, but we believe that the main problems are tied to the underlying approach, which while mathematically sound proves to be cognitively difficult. We analyze the limitations, and suggest approaches for future work in multi-view sketch-based modeling. Key words: Sketch-based interfaces, shape modeling.