Symbolic Constraints In Constructive Geometric Constraint Solving

In this paper we show how geometric problems defined by constraints with interval parameters can be solved by combining a symbolic geometric constraint solving phase and a numerical evaluation phase based on interval analysis techniques.

Geometric constraint programming increases flexibility in CAD design specifications and leads to new conceptual design paradigms. This volume features a collection of work by leading researchers developing the various aspects of constraint-based product modeling. In an introductory chapter the role of constraints in CAD systems of the future and their implications for the STEP data exchange format are discussed. The main part of the book deals with the application of constraints to conceptual and collaborative design, as well as state-of-the-art mathematical and algorithmic methods for constraint solving.

In the report, we present some ideas how to extend the drawing scope and to improve the interactivity and f1exibility of constraint-based geometric modellers and drawing systems. These ideas were employed in the experimental 2D drawing system GemmaCAD 2D. Its main feature is the early exit for constraint problems solvable by an insertion of redundant constraints. This task is based on simple rules for solving triangles and calculation of sums of adjacent angles, and some more powerful rules for solving quadrangies. If a problem cannot be solved by local propagation after insertion of redundant distances and angles, it is partitioned into independent subproblems, and these are then solved by the well-known numerical optimisation method BFGS. We propose some ideas addressing partition and preparation of equations. All constraints are presented by the point coordinates. only. This transformation usually improves convergence, enables simple calculation of derivatives required by BFGS in symbolic form, and allows us to extend the constraint set by new constraint types.

This book provides a comprehensive coverage of the fields Geometric Modeling, Computer-Aided Design, and Scientific Visualization, or Computer-Aided Geometric Design. Leading international experts have contributed, thus creating a one-of-a-kind collection of authoritative articles. There are chapters outlining basic theory in tutorial style, as well as application-oriented articles. Aspects which are covered include: Historical outline Curve and surface methods Scientific Visualization Implicit methods Reverse engineering. This book is meant to be a reference text for researchers in the field as well as an introduction to graduate students wishing to get some exposure to this subject.

The Handbook of Geometric Constraint Systems Principles is an entry point to the currently used principal mathematical and computational tools and techniques of the geometric constraint system (GCS). It functions as a single source containing the core principles and results, accessible to both beginners and experts. The handbook provides a guide for students learning basic concepts, as well as experts looking to pinpoint specific results or approaches in the broad landscape. As such, the editors created this handbook to serve as a useful tool for navigating the varied concepts, approaches and results found in GCS research. Key Features: A comprehensive reference handbook authored by top researchers Includes fundamentals and techniques from multiple perspectives that span several research communities Provides recent results and a graded program of open problems and conjectures Can be used for senior undergraduate or graduate topics course introduction to the area Detailed list of figures and tables About the Editors: Meera Sitharam is currently an Associate Professor at the University of Florida’s Department of Computer & Information Science and Engineering. She received her Ph.D. at the University of Wisconsin, Madison. Audrey St. John is an Associate Professor of Computer Science at Mount Holyoke College, who received her Ph. D. from UMass Amherst. Jessica Sidman is a Professor of Mathematics on the John S. Kennedy Foundation at Mount Holyoke College. She received her Ph.D. from the University of Michigan.

This book constitutes the thoroughly refereed post-workshop proceedings of the 10th International Workshop on Automated Deduction in Geometry, ADG 2014, held in Coimbra, Portugal, in July 2014. The 11 revised full papers presented in this volume were carefully selected from 20 submissions. The papers show the trend set of current research in automated reasoning in geometry.