In this paper, we present techniques for integrating constraint and direct manipulation approaches to geometric modeling. Direct manipulation positioning techniques are augmented to provide the option of making the relationships they establish persistent. Differential constraint techniques are used to maintain these relationships during subsequent editing. Issues in displaying and editing constraints are also addressed. By integrating constraints with direct manipulation, it is possible to build systems that provide the power of explicit representation of geometric relationships and the propertieswhich make direct manipulation so attractive.

@InProceedings{Gle92,
  author       = "Gleicher, Michael",
  title        = "Integrating Constraints and Direct Manipulation",
  booktitle    = "1992 Symposium on Interactive 3D Graphics",
  pages        = "171--174",
  month        = "mar",
  year         = "1992",
  url          = "http://graphics.cs.wisc.edu/Papers/1992/Gle92"
}