Dr. Stephen Wismath

Professor Emeritus
Department of Mathematics and Computer Science,

University of Lethbridge,

4401 University Dr.,
Lethbridge, Alberta,
Canada
T1K-3M4

e-mail:

My Curriculum Vitae in pdf form.


Biography:

Dr. Wismath received his Ph.D. in Computer Science from U.B.C. in 1989. He obtained his B.Sc. (Hons., Mathematics) with a minor in Computing Science in 1975 and an M.Sc. (Computing Science) in 1980 from Queen's University. He is a Professor Emeritus and taught primarily computer science courses at the University of Lethbridge since 1983. He took a turn as Chair of the department, finishing June 30, 2009.


Hobbies:

I've been a runner for over 50 years and have completed 7 marathons and numerous shorter races (mostly 10 mile and 1/2 marathon distances recently). I also play go regularly and avidly.


Teaching:


No further teaching duties! Ever.

Here are some projects generated by my students in the Computer Graphics course recently.


Research Interests:

circle drawing

Currently, the main focus of my research is examining the nature and structure of visibility among objects in the plane and determining efficient and practical algorithms for such problems. More recently, graph drawing in three dimensions has been of primary interest. In general, my research can be categorized as: Analysis of Algorithms, Computational Geometry, Graph Drawing, Visibility Graphs. I gratefully acknowledge NSERC for their support of my research.

Conferences

I was invited to give a talk at Graph Theory with Altitude in May 2005.

I was invited to give a course on 3-Dimensional Straight-Line Graph Drawing at the Journees de Geometrie Algorithmique 2002 held in Obernai, France, Oct 14-18, 2002.

I hosted the 14th Canadian Conference on Computational Geometry here in Lethbridge August 12-14, 2002. Together with Hazel Everett (LORIA, U. Nancy, France), I was editor for a special issue devoted to this conference in the journal Computational Geometry: Theory and Applications Volume 28, Issue 1 [SPECIAL ISSUE], May-2004

Program Committees:

Recently:

Graduate Students:

LillAnne Jackson -- graduated in 1996. Thesis: Polygon Reconstruction from Visibility Information.

Elspeth Nickle -- graduated in Fall 2005 Thesis: Classes of Arrangement Graphs in 3D.

Sebastian Hanlon -- graduated in Spring 2006. Thesis: Visualizing 3D Graph Drawings.

Andrew Butcher -- cosupervised with Matt Tata (Neuroscience) -- graduated Spring 2012 Thesis: Free Field Auditory Localization and Perception.

Joel Bennett -- cosupervised with Kevin Grant -- graduated Fall 2014. Thesis: Voxel Octree intersection based 3D scanning.

Farshad Barahimi -- graduated Summer 2015 Thesis: Web-based drawing software for graphs in 3D and two layout algorithms.

Summer research (undergraduate) students:

In the last several years, I have hired the following students to work on research projects: Helen Pinto, Michael Closson, Breanne Dyck, Shane Gartshore, Ray Dufresne, John Johansen, Jill Joevenazzo, Jon Wilsdon, Kim Hansen, Sebastian Hanlon, Carrie Wang, Ethan Kim, Garret Johnson, Amy Smith, Ian Stewart, Fei Wang, Lezar DeGuzman.

Research Projects and Software:

3D Graph Visualization with the Oculus Rift with Farshad Barahimi is a poster accepted and presented at Graph Drawing 14.

Animation of an Algorithm for Drawing Graphs in 3D with Lezar DeGuzman is an animation accepted and presented at the Symposium on Computational Geometry, 2014 in Kyoto, Japan It comes in both a 2D and a 3D version.

3D Printed Graphs with GLuskap (with Joel Bennett) was a poster accepted and presented at Graph Drawing 13.

The GLUSKAP (version 3.0) package for 3D graph drawing is now available. An earlier version was presented as a poster at Graph Drawing 2003. Using this software we entered the graph drawing contest associated with the GD03 conference and tied for 2nd place. Our entry includes 2 animations and a stereogram poster.

An animation (by Carrie Wang with some post processing by Kim Hansen) is on upward drawings of trees in 3D and was entered in the Graph Drawing 2005 freestyle contest.

We have several other projects on the go. See this web site for various projects.

An animation on drawing planar graphs produced by my student Kim Hansen was accepted and presented at the Symposium on Computational Geometry 2005 Multimedia and Video session in Pisa, Italy, in June 2005.

Some more animations and pictures describing a paper on drawing planar graphs on curves is available both in English and Italian!

Software for drawing arrangement graphs in 3 dimensions was developed by Ray Dufresne: ArrangePak3D

In the Summer of 2002, I had 2 students working for me on upgrading the packages described below and making some lovely animations related to 3d graph drawing.

One project of interest to researchers in visibility graphs is the VisPak package of visibility algorithms written here at the U. of Lethbridge under my supervision.

My students have also written a package for manipulation of arrangements of lines and pseudo-lines (ArrangePak) and a package for 3-d orthogonal drawing of graphs (OrthoPak). This software is freely available for research and teaching purposes. You may download the PACKAGES.

An applet displaying the Z-planes of a 3-D orthogonal drawing of K100 is available that displays some joint work with T. Biedl, T. Shermer, and S. Whitesides.

An applet implementing an algorithm for determining an inducing path of length n in a set of lines can be viewed - joint work with J. Bose, and H. Everett.

A brief animation of some work on an orthogonal 3-d construction technique that we are developing can be viewed: Compressed version (about 4M)
Uncompressed (13M)

The following is an animated gif of some work on 3d graph drawing. Can you identify the graph?

animated K7

Selected Publications and Conference Presentations:

Note that the electronically available papers are for personal use only, and in some cases copyright rests with a publishing company.
An alternate research summary with pictures is also available.