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.