Issue No. 05 - September/October (1993 vol. 13)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/38.232098
<p>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.</p>
R. Bartels and B. Fowler, "Constraint-Based Curve Manipulation," in IEEE Computer Graphics and Applications, vol. 13, no. , pp. 43-49, 1993.