Interactive sketch interpretation using arc-labeling and geometric constraint satisfaction

Abstract: "This paper describes the algorithms used by Viking, a solid modeling system whose user-interface is based on interactive sketch interpretation. Pencil and paper sketches are widely used early in the design process. Viking's user-interface lets the user create these sketches on the computer and automatically generate the corresponding three-dimensional interpretation. This user-interface combines the simplicity of pencil and paper sketches with the power of a solid modeling system. Sketch interpretation combines arc-labeling and constraint satisfaction. Arc-labeling generates a surface topology for the interpretation.This algorithm extends the line-labeling methodology to non- trihedral objects and uses heuristics to generate interpretations in order of decreasing desirability to the user. Constraint satisfaction solves for the vertex positions in the interpretation. Constraints are either generated from implicit relations in the line-drawing or explicitly created by the user."