[ont.events] COMPUTER GRAPHICS SEMINAR

eas@utcsrgv.UUCP (Ann Struthers) (12/11/84)

			*** LATE ANNOUNCEMENT ***

		       COMPUTER GRAPHICS SEMINAR

                   
		       Tuesday, December 11, 1984

		     Sandford Fleming Building 1105


			  
			    Mark Green
                    Department of Computer Science
	              	University of Alberta
			 Edmonton, Alberta


               "The Design of Graphical User Interfaces"

A new approach to the design of graphical user interfaces is presented. This
approach is based on a design methodology and a set of design tools supporting
this methodology. The design methodology is motivated by research in both
ergonomics and software engineering. It consists of seven orthogonal design
tasks. Each of these design tasks has one well defined goal and a document
that records the result of the task. The division of the design process into
tasks allows the designer to concentrate on one aspect of the design at a time
and gives the design manager ability to establish milestones. A unique feature
of this design and methodology is its concentration on design evaluation and
correctness.

A consistent set of tools has been developed to support this design metho-
dology. The most important tools are a user modeling language for describing
the user's view of the problem and the user interface, and a specification 
language for user interfaces. The user modeling language is based on the
concepts of objects and operators. The specification language is based on
state machines. The combination of these two languages covers all four levels
in the language model of user interfaces propose by Foley. Techniques have
been developed for showing the compatibility of different descriptions of
the user interface and for calculating important ergonomic measures given
a description of the user interface.

henry@utzoo.UUCP (Henry Spencer) (12/11/84)

It would be nice to know *when* Mark's talk is...
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry

wlrush@water.waterloo.edu (Wenchantress Wench Wendall) (06/22/89)

Apple Computer, will speak on ``An In-Place Image Zoom Algorithm.''


DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

COMPUTER GRAPHICS SEMINAR

                    -Monday, June 26, 1989

Mr. Paul Heckbert, University of California-Berkeley and Apple Computer,
will speak on ``An In-Place Image Zoom Algorithm''

TIME:                 3:30 p.m.

ROOM:              DC 1302

ABSTRACT

Standard   image   processing   algorithms  operate  in
scanline  order.  If one attempts to translate or scale
an   image  with  overlapping  source  and  destination
windows using such an algorithm, information-destroying
feedback results.  Borrowing tricks from block transfer
firmware,  we  can  make  slight  modifications  to the
scanline algorithm to eliminate all feedback.  Happily,
the  technique  generalizes  easily  to allow arbitrary
finite   impulse  response  filtering.   The  resulting
algorithm  for  in-place filtered image zooming appears
to  subsume  previous  one-pass scanline algorithms for
both  in-place FIR filtering and in-place zooming, with
no loss in efficiency.

wlrush@water.waterloo.edu (Wenchantress Wench Wendall) (02/22/90)

will speak on ``Simulation of Dynamic Systems with 
Solid Modeling Support.''


DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

COMPUTER GRAPHICS SEMINAR

                    -Friday, March 2, 1990

Dr.   George   Vanecek  Jr.,  Purdue  University,  West
Lafayette,  Indiana,  will  speak  on  ``Simulation  of
Dynamic Systems with Solid Modeling Support''.

TIME:                 3:30 p.m.

ROOM:                 DC 1304

ABSTRACT

Newton  is  a  system  developed jointly at Cornell and
Purdue  for  simulating  systems  of  physical objects.
Much  of  Project  Newton  depends  on the support of a
solid  modeler.   This  includes the ability to create,
and  modify  solid  objects,  as well as to obtain mass
properties  of  objects,  or  to  determine the spatial
interaction between two objects.

To  provide such broad support, a solid modeling system
called   ProtoSolid   has  been  connected  to  Newton.
ProtoSolid  is a solid modeling system developed at the
University  of  Maryland.  It supports the creation and
modification    of    arbitrary    polyhedral   solids.
ProtoSolid  is  written in Common Lisp and runs on Lisp
machines  such  as  the Symbolics and the TI/Explorers.
It  can  also  be easily ported to any all-purpose UNIX
machine.

Internally, ProtoSolid models the boundaries of solids.
The solids are polyhedral objects including solids with
nonmanifold  topologies.   In  addition to the boundary
representation,  two other representations are provided
for  solids.   The  first  is a high level language for
specifying   the   operations   and  the  parameterized
primitives  for  creating  solid.  Among the operations
are  Boolean set operations for combining, intersecting
and  subtracting  two  solids,  and Euler operators for
making local changes to the boundary of a single solid.
Simple  solids  can  be instantiated from parameterized
primitives  such  as  block, cone, cylinder, sphere and


                         - 2 -

torus,  or  may  be  created as solids of revolution or
extrusion  from  contours.   ProtoSolid  can  translate
objects  into  a  second,  volume-based representation.
Here,  the volume of a solid is given by a binary space
partition  (BSP)  tree.   It  can be easily constructed
from   the   boundary   representation.    Volume-based
operations   such   as   point/solid   and   line/solid
classification,  and  detection of the interpenetration
of two solids are efficiently supported by BSP trees.

With  this  solid  modeler  it is possible to implement
algorithms that determine collision times of two moving
objects,  and  to analyze the point or surface contacts
of  the  collisions.   With  the  ability to detect and
resolve  collisions, and obtain mass properties such as
volume,  surface  area,  center  of  mass,  and various
moments  of  inertia,  the modeler readily supports the
Newton simulation system.  Currently, Project Newton is
a  distributed  system  consisting  of a graphical user
interface   on   a  Personal  Iris  that  utilizes  two
Symbolics  3620s,  one  with  ProtoSolid, and the other
with the Newton simulation system.

This  talk presents project Newton with emphasis on the
solid modeling support.