### Tuesday, November 2

## MS4

Consistent Topology and Geometry for CAGD

4:15 PM-6:15 PM

*Room: Rio Grande Ballroom*

In geometric modeling, exact symbolic data is used to represent topological
information whereas the corresponding geometry is only approximated. The approximations
within geometry creation algorithms must balance data volume, degree of the
surface and curve representations, and performance expectations, in the context
of floating point arithmetic. Today, informal use of tolerance values often
leads to unexpected results, particularly for distributed geometric design.
Progress requires both new mathematics and improved implementations. The speakers
in this session will illustrate how new uses of topology, numerical analysis,
and logic are leading to improved software prototypes for geometric modeling.

**Organizer: Thomas J. Peters**

*University of Connecticut, Storrs*

**4:15-4:40 Perturbations of Well-Formed Solids**
- Neil F. Stewart, Univeristé de Montréal, Canada
**4:45-5:10 Application Specific Equivalence Classes of Geometric Objects**
- Miriam L. Lucian, The Boeing Company
**5:15-5:40 Validity Verification and Rectification of B-rep Models**
- Nicholas M. Patrikalakis, Massachusetts Institute of Technology;
*Takis
Sakkalis*, University of Athens, Greece; and Guoling Shen, Massachusetts
Institute of Technology
**5:45-6:10 Regular Closed Sets in Geometric Modeling**
- Thomas J. Peters, Organizer

*Created LMH, 5/18/99; Last Updated MMD, 6/15/99
*