Category: CMUTR
Institution: Department of Computer Science, Carnegie
        Mellon University
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 inter-
        pretation.
        This algorithm extends the line-labeling methodology to non-
        trihedral objects and uses heuristics to generate inter-
        pretations 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.
Number: CMU-CS-91-181
Bibtype: TechReport
Month: Sep
Author: David Pugh		
Title: Interactive Sketch Interpretation Using Arc-labeling and
        Geometric Constraint Satisfaction
Year: 1991
Address: Pittsburgh, PA
Super: @CMUTR