CGL Meeting Agenda

Wednesday, November 20th, 1996

Valid HTML
Location:
DC 1304
Time:
11:30 AM
Chair:
Balasingham Balakumaran

1. Adoption of the Agenda - additions or deletions

2. Coffee Hour

Coffee hour this week:
Tali Zvi
Coffee hour next week:
To be determined

3. Next meeting

Date:
November 27th, 1996
Location:
DC 1304
Time:
11:30 AM
Chair:
Bill Cowan
Technical presentation:
Balasingham Balakumaran

4. Forthcoming

Chairs:
  1. Itai Danan
  2. Matthew Davidchuk
  3. Chris Davies
Tech Presenters:
  1. Bill Cowan
  2. Itai Danan
  3. Matthew Davidchuk

5. Technical Presentation

Presenter:
Richard Bartels
Title:
Towards a Generic Editor for Subdivision Surfaces
Abstract:
We'll tell you what a subdivision surface is and what software abstractions we looked at to produce an editor that can edit a number of different surfaces in a uniform way.

6. General Discussion Items

  1. CGL Christmas party -time -location
  2. Lab meeting next term - time

7. Action List

  1. Navid Sadikali and Richard Bartels:
    UofT visit in April

8. Director's Meeting

9. Seminars



           The Institute for Computer Research (ICR)

                      Presents a Seminar on

"Recent Progress in Modelling and Simulation of High-Speed VLSI Interconnects"


by:     Dr. Michel S. Nakhla

of:     Department of Electronics

        Carleton University


Date:   Monday, November 25, 1996

Time:   10:00 a.m.

Place:  William G. Davis Computer Research Centre, Room 1304



Abstract:

The intense drive for signal integrity has been at the  forefront
of  rapid  and new development in CAD algorithms. With increasing
demands for high signal speeds coupled with a decrease in feature
size,  interconnect  effects such as signal delay, distortion and
crosstalk become the dominant factors  limiting  overall  perfor-
mance of VLSI systems. On the other hand, interconnect structures
can be diverse and present at any of the  hierarchical  packaging
levels  including  integrated  circuits,  printed circuit boards,
multi-chip modules  and  backplanes.  Although  conventional  CAD
tools such as SPICE are used routinely by many engineers for ana-
log simulation and general circuit analysis, these tools  do  not
handle adequately the new emerging challenges of interconnect ef-
fects.

Moment-matching techniques have recently  proven  useful  in  the
analysis of large interconnect structures containing lossless and
lossy high-speed interconnects with linear or nonlinear  termina-
tions. At a CPU cost of a little more than one DC analysis, these
techniques are 2-3 orders of magnitude faster  than  conventional
methods.

In this talk  an overview of interconnect  simulation  techniques
will be presented with emphasis on the diverse algorithms and ap-
plications of moment-matching techniques.  The  underlying  basic
concepts will be demonstrated by several practical examples.


Host: Professor Ajoy Opal, Electrical and Computer Engineering



Everyone is welcome.  Refreshments served.



ICR gratefully acknowledges the support of its Corporate  Members
for  this  Seminar  Series:  DALSA INC., Hewlett-Packard (Canada)
Ltd., and NCR Canada Limited.




CS Colloquium Series
Computer Science Department
University of Waterloo


What Does It Mean To Be Right In Realistic Computer Graphics?



By:		Eugene Fiume
Of:		Department of Computer Science
		Alias/Wavefront and
		University of Toronto

Date:		Tuesday, November 26, 1996

Time:		4:00-5:00

Place:	        Davis Centre, Room 1304

Abstract:

The development of techniques to realistically model and render 
interesting visual phenomena is a preoccupation of many researchers in 
computer graphics.  Most of us work by adapting models from other 
mathematical sciences, from which we hope to derive good visual 
depictions.  But just what is a "good" depiction, and how true do we 
need to be to the "reality" expressed by mathematical models?  Perhaps 
by framing the question around a case study, some glimpses of an answer 
may emerge.  We consider the issue of visual error and distinguish it 
>from  numerical error.  We will then look at some recent work done with 
Jos Stam on the depiction of smoke, mist and fire under the influence of 
turbulent wind fields.  We use a stochastic model for generating 
fine-scale turbulence, and we use advection-diffusion equations to mimic 
the evolution of gaseous densities (e.g., wisps of smoke), temperature 
(fire), and light (multiple scattering).  At each step, we shall make 
egregious assumptions but the results nevertheless look pretty darned 
good.  Is realistic computer graphics just smoke and mirrors, or is it 
an emerging mathematical science of visual depiction? Both.

Biography:

Eugene Fiume has been on faculty in the Department of Computer Science 
at the University of Toronto since 1987.  From 1987-1992, he was also an 
NSERC University Research Fellow, and he helps to run the Dynamic 
Graphics Project.  Prior to his faculty appointment, he was Maitre 
Assistant at the University of Geneva, Switzerland.  He holds Ph.D. and 
M.Sc. degrees from the University of Toronto, and a B.Math. from the 
University of Waterloo.  His sabbatical last year was split between 
iMAGIS in Grenoble, France, and Alias/Wavefront in Toronto.  This year 
he has been splitting his time between the University of Toronto and 
Alias/Wavefront.  He won ITRC's Innovation Award in 1995 and a couple of 
teaching awards; he is a member of several scientific advisory boards, 
and he has published two books and about fifty papers.

Everyone is welcome



COMPUTER GRAPHICS SEMINAR

                    -Wednesday, November 27, 1996

Guenther  Greiner, IMMD, Friedrich Alexander University
of Erlangen-Nuernberg, Germany, will speak on ``Splines
in  Real  World  Applications:  CNC-Programs  and  Lens
Design''.

TIME:                3:30-4:30 p.m.

ROOM:                DC 3301

ABSTRACT

In  the  talk  we  present  two  applications of spline
theory.   Both  have  been  developped  with industrial
partners:

(1)   Optimization   of   CNC-Programs   (with  Siemens
Automation Group, Erlangen)

Modern  CNC control units can process spline data. Many
of  the  existing  NC-programs  still  use  linear path
description   for   specifying   the  geometry.   These
descriptions  usually  require  a  huge amount of data,
thus  making  the  production  process  very  slow.  By
conversion to a cubic spline representation, the amount
of  data  can  be  reduced  substantially.  Of  course,
specified  tolerances  have  to  be  met.  Among  other
features,   sharp   edges   have  to  be  detected  and
preserved.

(2)  Design of progressive lenses (with R + H, Optische
Fabrik, Bamberg).

When  designing  progressive lenses, i.e. lenses with a
varying refracting power, one cannot avoid that optical
errors  (astigmatism)  occur.  The aim is to keep these
errors  as  small  as  possible and try to move them to
non-important regions (boundary of the lens).  The tool
developed  uses  the  variational  approach  to  spline
modeling, i.e. suitable functionals will be minimized.

10. Lab Cleanup (until 12:30 or 5 minutes)