Title : 
Constraint-based curve manipulation
         
        
            Author : 
Fowler, Barry ; Bartels, Richard
         
        
            Author_Institution : 
Pacific Data Images, Sunnyvale, CA, USA
         
        
        
        
        
        
        
            Abstract : 
Alternative techniques for control-vertex manipulation of parametric curves are described. Their generality and flexibility make possible a wide range of curve-editing interfaces based on direct manipulation. A method for applying systems of constraints at one or more arbitrary points on a single or composite curve and an efficient technique for the interactive application of these systems are outlined. Analytic solutions and examples for useful systems of constraints are presented.<>
         
        
            Keywords : 
computational geometry; computer graphics; curve fitting; composite curve; constraint-based curve manipulation; control-vertex manipulation; curve-editing interfaces; direct manipulation; interactive application; parametric curves; Control systems; Equations; Graphics; Shape control; Solid modeling;
         
        
        
            Journal_Title : 
Computer Graphics and Applications, IEEE