Siggraph '92 Preliminary Program
Steve Connelly
The Siggraph `92 Conference On Computer Graphics and Interactive
Techniques will be held July 27 - 31 in Chicago, Illinois. The following
contains selected portions of the Siggraph '92 Preliminary Program :
COMPUTER GRAPHICS ACHIEVEMENT AWARD
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Presented to persons who have significantly influenced the progress
of the computer graphics industry.
This Year's Winner : Elle Macpherson
Ms. Macpherson accounts for 97% of all GIF image files transmitted
among computing professionals, insuring that GIF will become the standard for
network image interchange.
KEYNOTE ADDRESS
===========================================================================
"State-of-the-Art in Anal-Retentive Illumination Models" by Don Greenberg.
Dr. Greenberg will review illumination models that for two decades
have maintained the Law of Constant Rendering Time, which states that the time
needed to render a high-quality image shall be one full day, regardless of the
speed of the hardware.
Just a few years ago, ray tracing a surface would take all day.
However, that is no longer true, and so more complex illumination models are
needed. According to the new treatise by Greenberg, Torrance, Sparrow, and
Cook entitled "Wait, It's Not That Simple", current research considers each
diffusely reflecting surface patch to be an irregular assembly of microfacets.
The microfacets must be ray traced to get reflection coefficients. If this
doesn't take long enough, then each microfacet itself can be considered as an
assembly of smaller facets. This subdivide-and-publish paradigm should insure
that illumination methods will defeat the hardware for years to come.
INVITED LECTURES
========================================================================
"How to Convert Your Head into a Twisted-Pair Junction Box", by Jaron Lanier.
"Incomprehensible Rendering of 3-D Shapes", by Yoichiro Kawaguchi.
COERCED LECTURE
============================================================================
"Further Thoughts on Implicitization", by Thomas Sederberg.
It's clear by now that implicitization of parametric surfaces was a
bad idea. This paper explains how to re-explicitize any surfaces you may
have mistakenly implicitized. Then we'll call it even, no harm done, okay?
TECHNICAL PAPERS
=========================================================================
Drawing : The Faster, Cheaper, More Flexible Alternative to Computer Graphics.
The Desktop : An Intuitive Physical Metaphor for Representing Windowing
Systems Within a Virtual Reality.
Boogers : Deformable, Viscoelastic Primitives that Merge Together Smoothly.
The Freehand Generation of Fractal Curves using only a Lightpen and Caffeine.
Stereosterone : The Male Visual Hormone that Makes 5 Inches Appear to be 14.
"Where is 100110101110101101-ikstan?" : Using K-d-trees to Manage the Nested
Recursive Subdivision of the Soviet Union.
Impressionism : Aliasing by the Great Masters.
Simulation of Protein Folding with Applications to the Design of Cursive
PostScript Fonts.
TUTORIALS
=====================================================================
Fundamentals Seminar
~~~~~~~~~~~~~~~~~~~~
Again in 1992, Siggraph will host a Sunday seminar for those who are
forced to stay over Saturday night to qualify for the excursion fare.
Attendees will learn the basics of computer graphics, including the so-called
"paint" packages, and digital "windows" with the capability to "cut" images and
"paste" them elsewhere. We will also consider the "viewing" through a
synthetic "camera" of "surfaces" positioned in "space" and "illuminated" by
ersatz "lightsources". As lecturer Edwin "Ed" Catmull notes, "To paraphrase
Milton, 'Our ''reality'', like ''beauty'', is in the virtual ''eye'' of the
proverbial ''beholder'''".
Basic Algorithms Analysis
~~~~~~~~~~~~~~~~~~~~~~~~~
Attendees will learn how to prove the optimality of their algorithms,
so that when their algorithm produces lousy results they can at least claim
that no one else can do better.
Applications of Planar Fractals
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Julia and Mandelbrot sets, originally thought to have no application
at all, have displaced Blinn's Blobby Lava Lamp as the Mac screensaver of
choice among the new age Silicon Valley heads. However, the Vivarium project,
a simulated ecosystem whose purpose has baffled experts, is poised to overcome
fractals as the screensaver of the 21st century.
Marijuana cigarettes will not be available as the call for papers
was not issued in time.
State-of-the-Art in Naming Those Sombrero-Shaped Functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The names "Laterally-Inhibiting Receptive Field", "Windowed Sinc
Function", "Laplacian", "Cardinal Spline", "Gabor Function", and
"Difference-of-Gaussian" are being superceded by "Wavelet".
Solving Graphics Problems with Wide-Area Networks
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When faced with a graphics problem, e.g. how to calculate the distance
between a point and a line, degree-seeking students find it easiest to ask
for the answer on a graphics-related InterNet newsgroup. Attendees will learn
how to post their questions so they don't sound like homework problems. We
will also learn why we get rude responses when we ask for a public-domain
package for intersecting two lines, or when we ask for a C procedure that
converts a photograph into a CAD database.
ABSTRACTS OF SELECTED TECHNICAL PAPERS
======================================================================
Generalized Condoms
~~~~~~~~~~~~~~~~~~~
Although typically used for surfacing cylindrical models, the membrane
and thin plate terms of the condom allow arbitrary deformations of the surface
without tearing. Furthermore, one size fits all models. Thus, like
convolutional surfaces and global splines, the condom can be used to skin
highly-articulated skeletal armatures.
Color, texture, and bump mapping are discussed. A top-down, scanline
approach to rolling the surface over the armature is presented.
Auropresence
~~~~~~~~~~~~
Our research team at AT&T has designed and deployed into every home
in the nation a communications network that provides real-time, two-way audio
virtual reality, or "auropresence". Experiments show that cybernauts, using
unobtrusive hand-held headsets, interact verbally with remote users as if all
parties were in the same room.
Graphics Hardware Acceleration for Hierarchical Splatting
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We discuss how to impose a hierarchy of point-spread functions when
rendering volume visualizations using arrays of Stardent graphics
supercomputers. Our method is based on the observation that, the higher the
window that the Stardent is thrown out of, the more time the graphics hardware
can accelerate and thus the larger the splat upon the concrete.
The Oz-slow Algorithm for Vector Field Visualization
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Weightless streamlining witches, cows, and loved ones are advected
into the flow field and observed from the door of the viewing house, a
spinning framework that itself follows path integrals through the dataset.
Data can be sent somewhere over the rainbow colormap, where it will be
rendered in technicolor.
Paper : Image Processing within a PostScript Interpreter
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PostScript interpreters tuned to process text often have access to
thousands of bitmapped fonts. We suggest that such interpreters can also
succeed in processing gray-tone images by converting the images into arrays of
characters.
Scaling an image can be performed simply by changing the font's point
size. Contrast is enhanced by changing to a bold font. Rotation is
implemented by using italic fonts; repeatedly italicizing horizontally and
then vertically will accomplish the Catmull-Smith two-pass image rotation
algorithm.
With enough fonts, a given font will be assured that all its affine
transformations are simply other existing fonts. Thus, according to the
Collage theorem, Iterated Function Systems can be used to encode images given
a single letter from any font. This will work especially well for encoding
images of text.
Paper : Digital Simulation of a Painter's Materials
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We present a digital paint system which simulates the surface behavior
and dynamics of time-tested painting implements. The system manages the video
display so that it exhibits the irregular structure of a cave wall, and the
system allows the user to choose colors from a pallete of crushed berries and
animal organs. PostScript output onto a real cave is discussed.
Ethical Considerations in Graphics Production
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In 1989, researchers at the University of Illinois at Urbana-Champaign
were applauded for their "Study of a Numerically Modeled Severe Storm", a
dynamic visualization of data derived from the simulation of a synthetic
tornado. However, it has been recently revealed that their data was not fake,
but was in fact real. We discuss the fallout of the ensuing scandal.
Paper : Memory Technologies for Direct Volume Visualization
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We at the Computer Museum in Boston just realized that our museum is
filled with junk. You think you're clever, unloading your computer garbage on
us like we were Jersey. Well, forget about history. From now on we're doing
volume visualization, on the leading edge.
In volume visualization, the task is to render the data so that it
appears to have a 3D physical form. However, this task can be avoided if
the data is held in a memory device that itself has a 3D physical form.
In addition to its volumetric shape, the memory components must be large
enough to be visible to the naked eye. The only memories that fulfill these
constraints are the ferrite core memories of the 60's. Binary voxel arrays
can be loaded into core memories that have been coated with magnetically
reactive pigment so that each core is white or black. In this way, a
researcher can comprehend his 3D data by walking around and peeking inside the
memory itself. And the memory is free; in fact, we'll pay you to move it out
of here.
MacKoax! from Coax Inc.
~~~~~~~~~~~~~~~~~~~~~~~
We present a product that is plug-compatible with Mac's, PC's, Unix
workstations, and all other SCSI, parallel, or custom ports. The device
operates at room temperature and does not require power. Its simple design
provides ISDN, TCP/IP, big-endian/little-endian functionality that accepts
PostScript, NTSC, voice, IGES, MIDI, Group 3, and all other formats, under the
condition that input and output formats are the same. The device works at
video rates and, because it doesn't do anything, it operates without any data
loss or distortion.
Paper : CAT Scan Visualization in PostScript
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We present a new method of using PostScript to visualize objects
formed from serial sections. Our method begins by thresholding the volume
data into a 3D bitmap of voxels that are either transparent or opaque. We
then iterate over all 2D sections, converting each into a PostScript bitmap.
We then send the bitmaps to our laser printer, which we have enhanced so that
the laser actually burns the paper away at the positions of transparent pixels.
As sections are printed off, they form a stack in the output tray. Eventually,
the CAT scan data volume is realized in solid paper, which can be bound in
book form.
Physics and the Mootness of Graphics
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Current trends in photorealistic graphics involve thermodynamics for
radiosity calculation, optics for ray tracing, classical mechanics for
physically-based animation, and Kirchoff's laws for reflection and absorption.
Thus, an undergraduate physics curriculum that uses computer simulations will
accidentally recapitulate all of computer graphics while resulting in a
kick-ass renderer.
FILM & VIDEO SHOW
==========================================================================
The Up With People chorus will give a live multimedia rendition of
"Chicago : It's Not as Bad as Detroit". Unfortunately, our usual laser show
has been hired away by the International PostScript Convention. However, we
do have a flatbed plotter whose pens have been replaced with lasers.
PostScript path files submitted to the plotter will be drawn calligraphically
on the projection screen.
PDI Morph Reel
~~~~~~~~~~~~~~
For a recent Michael Jackson music video, Pacific Data Images created
what is to date the longest continuous raster image morph sequence, involving
transitions between more than a dozen completely different human faces. Each
face was Michael Jackson after a plastic surgical operation. Digital
extrapolation was used to predict Jackson's future appearance as he achieves
his goal of a "Siamese-Cat-with-Kirk-Douglas-Chin" look.
Excerpts from "Terminator 2"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In the future, blobby models (metaballs, equipotential isosurfaces)
will enjoy continued success over competing surface methods. All other
modeling technologies will be made obsolete while blobby models will become a
world-wide standard. Eventually, Blobbies will decide they don't need the
humans. Shiny, environment-mapped deformable pseudopods will go on a rampage
and nearly terminate the human race.
In "Terminator 2", a Blobby travels back in time in order to terminate
a boy named Pierre Bezier, the only person who can stop blobby modeling from
taking over. The Blobby terminator's ability to distend his shiny metallic
anatomy to any length lets him become a successful porno star named Long Dong
Silver.
The Making of "Starwatcher"
~~~~~~~~~~~~~~~~~~~~~~~~~~~
For the feature film "Starwatcher", new techniques in the modeling
of totally synthetic scenes have been perfected. A Cyberware scanner is used
to digitize real faces in a variety of facial expressions while mouthing all
possible phonemes. The Data Suit is worn by live actors and domesticated
animals to capture natural-looking action. Textures and scenery are derived
from sonar and optical recordings taken on-location. Clay models are moved
incrementally and then laser digitized to create a different 3D object to be
rendered for each frame. By combining these techniques, "Starwatcher" will
become the first feature length film in the history of cinema that is entirely
computer-animated, completely untouched by human hands, involving no live
action footage at all.
Special Effects in the Next "Star Trek"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In motion pictures (such as Lawnmower Man, Looker, Return of the Jedi,
and the genesis effect in Star Trek 2), computer graphics effects have been
used quite successfully to depict, um, computer graphics. Now, the artifacts
of computer graphics will be used to best advantage in "Star Trek NaN : The
Wrath of Phong"....
< The landing party alpha-blends to opacity on the planet's surface. >
SPOCK : The tricorder indicates a complete lack of mirror reflections and
cast shadows. Also, if we travel too far from the origin, we will
suffer from round-off error. Captain, this planet is highly
dangerous; it was wise to bring expendable red-shirted security men.
< An expendable red-shirted security man turns to the side while looking
upward. His neck joint suffers gimbal lock, and he falls in a heap. The
group rushes to him. >
MCCOY : Jim, he's dead.
KIRK : < throws arms wide, ripping shirt > No quaternions? What kind of
planet is this?
< An omnipotent, dim-witted native of the planet approaches, walking through
cone-shaped trees and icosahedral boulders. His form is that of a matte gray
desk lamp. For no apparent reason, his light bulb flashes when he speaks. >
LAMP : Why does this death cause such grief, One-They-Call-Kirk? Was he not a
non-speaking extra?
KIRK : He was just an extra, yes, but still an actor, and, so, we, actors,
all of us, too, feel his pain, his agony. Regardless of age or
experience, each of my species belongs to a single screen actor's
guild.
< Another native of the planet, a curvaceous astro-bimbette, enters. >
ASTRO-BIMBETTE : When you open your mouth wide while over-acting, I can't see
out the back of your head. You are not from here, are you?
KIRK : We are from a far-away planet. And yet, like your sun, ours is a point
light source at infinity. We will return there soon.
A-B : Why must you leave? Does my form not please you?
KIRK : Oh, yes. Your complexion is very uniform, your surfaces are subdivided
to a pleasant smoothness, and your boundary representation implies that
your head is empty. My gender finds these traits attractive. Though
I'm sure your not just a Kirk-tease, I must nevertheless be going -
LAMP : Captain, please stay. Due to excessive instancing, the genetic
patterns of my people are identical. Without variety, our species is
threatened with extinction. If you do not impregnate all the young
women on our planet, we are doomed.
KIRK : < righteously > If there is one law that we live by, it is that all
species have the right to survive. Bones, help me service all these
women.
MCCOY : Dammit, Jim, I'm a doctor, not a firehydrant.
ADMINISTRATIVE NOTE
===========================================================================
We apologize if we have at times referred to Siggraph '92 as Sgigraph '92.
============================================================================
Postscript: This preliminary program was compiled by Steve Connelly and
Tim Hall (t...@agni.std.com).
--
Moderated by SCRI Vis <> Submissions to: grap...@scri1.scri.fsu.edu
Guy, John R. Murray <> Administrivia to: graphics...@scri1.scri.fsu.edu