Meeting Agenda

Date:	January 28th
Location:	DC 2314
Time:	1:30
Chair:	Andrea Bunt

1. Changes to the Agenda - additions or deletions

2. Coffee Hour

Coffee hour last week:: Cherry- thanks!
Coffee hour this week:: Volunteers?
Coffee hour next week:: Volunteers?

3. Forthcoming

Date:	February 4th	February 11th	February 18th	February 25th
Location:	DC 1331 1:30	DC 1331 1:30	DC 1331 1:30	DC 1331 1:30
Chair:	Bill Cowan	Gabriel Esteves	Elodie Fourquet	Richard Fung
Technical Presentation:	Cam Zwarich	Andrea Bunt	Bill Cowan	Gabriel Esteves

4. Technical Presentation

Stephen Mann	Title : Tessellating Algebraic Curves and Surfaces Using A-Patches Abstract: This work approaches the problem of triangulating algebraic curves and surfaces with a subdivision-style algorithm using A-patches. An algebraic curve or surface is converted from the monomial basis to the Bernstein-B\'ezier basis over a simplex. If the coefficients are all positive or all negative, then the curve or surface does not pass through the domain simplex. If the scalar Bernstein coefficients are of mixed sign and have a layer separating the positive from the negative, then the patch is in A-patch format and can be efficiently tessellated. Cases of mixed sign without a separating layer are resolved by subdividing the structure into a set of smaller patches and repeating the algorithm. Using A-patches to generate a tessellation of the surface has the advantage of reducing the amount of subdivision required. And because of the A-patch properties, we are guaranteed that features within the designated region will not be missed.

Stephen Mann

Title : Tessellating Algebraic Curves and Surfaces Using A-Patches

Abstract:
This work approaches the problem of triangulating algebraic curves and surfaces with a subdivision-style algorithm using A-patches. An algebraic curve or surface is converted from the monomial basis to the Bernstein-B\'ezier basis over a simplex. If the coefficients are all positive or all negative, then the curve or surface does not pass through the domain simplex. If the scalar Bernstein coefficients are of mixed sign and have a layer separating the positive from the negative, then the patch is in A-patch format and can be efficiently tessellated. Cases of mixed sign without a separating layer are resolved by subdividing the structure into a set of smaller patches and repeating the algorithm.

Using A-patches to generate a tessellation of the surface has the advantage of reducing the amount of subdivision required. And because of the A-patch properties, we are guaranteed that features within the designated region will not be missed.

5. Discussion Items

None so far...

6. Action Items

7. Conferences and Special Journal Issues

8. Directors' Meeting

9. Seminars and Events

2009 Jan 28, 3:00 p.m., DC3323: Software Engineering Research Group PhD Seminar; Locating Features in Source Code: A Survey, Abbas Heydarnoori, PhD Candidate, David R. Cheriton School of Computer Science, University of Waterloo

2009 Jan 28, 3:00 p.m. - 4:30 p.m., DC1302 -- Smarter Health Seminar: Informatics and the Continuum of Care: The Changing Landscape, J. Wayne Gudbranson, President and CEO, Branham Group Inc.

2009 Jan 30, 9:30am, DC2314 -- PhD Defence (Supervisor: Craig Kaplan): Wholetoning: Synthesizing Abstract Black and White Illustrations, Jie Xu, PhD Candidate, David R. Cheriton School of Computer Science, UofW

2009 Jan 30,10:00am, DC3323 -- Computer Systems Group PhD Seminar

Towards Modeling and Verifying Distributed Event Based Systems, Rolando Maldonado Blanco, PhD Candidate, David R. Cheriton School of Computer Science, University of Waterloo 10:00 a.m.; DC3323

2009 Jan 30, 2pm DC 1331 -- Database Research Group PhD Seminar: High Availability Through Virtualization, Umar Farooq Minhas, PhD Candidate, David R. Cheriton School of Computer Science, University of Waterloo

2009 Jan 30, 2:30 p.m., DC1304 -- Computer Graphics Research Group Seminar: Removing Camera Shake from a Single Image, Aaron Hertzmann, University of Toronto

Also see other Math and CS postings.