Imager Events

SFU/Imager Visit 2003

Friday May 2nd, 2003

SFU Talks (2:00 - 2:45)  Location:  CICSR Board Room (CS 288)


Jason Sze
Understanding the Role of Haptics in Bimanual Coordination

Many of the tasks we perform each day make use of both our hands, and the
sensory output they provide gives us important information about our
environment.  Unfortunately, our current interaction technique with the
computer is predominately one-handed, mostly with the hand that controls the
mouse. Tasks which are normally performed simultaneously by the two hands
are now imposed on this single hand, resulting in longer execution time and
awkwardness.  As well, there is no "touch" information returned to us,
resulting in added awkwardness and inaccuracy. I'm interested in ways two
haptic mice can be used to improve this situation.

Richard Zhang
Spectral Processing of Mesh Geometry

Frequency-domain characterization of irregular triangle meshes based on
eigenvalue decomposition has led to some new and promising developments in
mesh filtering, compression, watermarking, and mesh partitioning. I will
first give a short 5-minute introduction to this topic and related
applications. Then I will concentrate on two new Laplacian operators that
can be used to derive the mesh spectrum and demonstrate their advantages
over existing operators, such as the combinatorial and discrete uniform
mesh Laplacian. If time permits, I will also talk about linear mesh
filtering using Butterworth filters and the numerical challenge we face.
Finally, some future research problems are suggested.

Reza Entezari
Wavelets on Hexagonal Lattices

This talk will quickly cover sampling lattices and advantages
of hexagonal lattices over the commonly used cartesian lattices
in sampling theory. The optimal sampling theory is then applied
to the subsampling operation when designing Perfect Reconstruction
filter banks for 3D volumetric datasets. Hence, a more efficient
multiresolution transform is obtained. The talk is then concluded
with some images obtained from this new non-separable subsampling
method versus the traditional separable subsampling methods.

UBC Demos (2:45 - 3:15)  (Forestry Sciences Center)

Dave Burke and Matt Thorne  
Motion Doodles:  A Sketch Based System for Character Animation
Location:  Imager Large (FSC 2330)

We present a system that uses a sketch-based interface to create and
animate a human figure.  First, a simple articulated figure is sketched
and decorated by the user, then the character is animated by sketching a
sequence of arcs and loops which are interpreted as jumps, leaps, flips
and steps.

Daniel Archambault
Visual Hull-Based Silhouette Edge Location on Distant Terrain
Location:  Imager Large (FSC 2330)

In Geographic Information System (GIS) applications, terrains are required
to express significant amounts of detail over large surface areas.  This large
amount of detail almost directly translates into a high polygon count for
their corresponding geometric models.  At great distances, a large amount
of this detail has little visual impact on the appearance of the terrain as
a whole.  Therefore many of these polygons can be omitted. 

In this research, we assume that the visually significant points of the terrain
are edges of the polygons in the terrain that support a line of sight that touches
no other point in the model.  These lines of sight are known as visual lines
through the works of Aldo Laurentini.  Our algorithm is designed to locate
all such edges on the terrain from any distant orthographic viewpoint 360
degrees around it.

Mario Enriquez with Karen MacLean
A Tool in Support of Haptic Communication Research
Location:  Experiment Room (FSC 2331)

We define haptic icons, or "hapticons", as brief programmed forces applied
to a user through a haptic interface, with the role of communicating a
simple idea in manner similar to visual or auditory icons. We present the
design and implementation of an innovative software tool and graphical
interface for the creation and editing of hapticons.
The tool's features include various methods for creating new icons including
direct recording of manual trajectories and creation from a choice of basis
waveforms; novel direct-manipulation icon editing mechanisms, integrated
playback and convenient storage of icons to file. We discuss some ways in
which the tool has aided our research in the area of haptic iconography and
present an innovative approach for generating and rendering simple textures
on a low degree of freedom haptic device using what we call terrain display.


Leah Findlater, Dustin Lang, and Michael Shaver
CoolPaint: Direct Interaction Painting
Location:  LIL (Lanscape Immersion Lab) (FSC 2430)

Traditional computer graphics packages have several drawbacks, including a
crude use of metaphor for virtual tools, an indirect interaction
technique, and limited orientation and size of the display. To create a
more immersive, natural painting environment, CoolPaint uses real
paintbrushes instrumented with six-degree-of-freedom trackers and a
large-scale tabletop display. The painting interaction occurs directly on
the display surface, removing the layer of abstraction found with mouse or
stylus input. The paintbrushes maintain their semantics through the use of
corresponding 3-dimensional virtual models for each brush.

UBC Demos (3:15 - 3:45) (Forestry Sciences Center)

Hendrik Kueck
Shape from Contours and Multiple Stereo - A Hierarchical, Mesh-Based Approach
Location:  Imager Small (FSC 2333)

In this project, we developed a novel method for 3D shape recovery based
on a combination of visual hull information and multi image stereo.  We
start from a coarse triangle mesh created from silhouette information.
The mesh is then hierarchically refined while its vertex positions are
optimized based on multi image stereo information.  This optimization
procedure utilizes 3D graphics hardware to evaluate the quality of
vertex positions, and takes both color consistency, and occlusion
effects as well as silhouette information into account.

Shu Zhen Wang
An Inexpensive 122 Million Pixel Scan Camera
Location:  Imager Large (FSC 2330)

In this work we present the design of a low-cost, very high
resolution scan camera which can be used in image-based modeling and
rendering, cultural heritage applications and professional digital
photography. The camera can take color/near-infrared images with the
resolution of 122 million pixels, while the camera itself can be built
from off-the-shelf components for only $1200. We will discuss the issues
in the hardware setup and the calibration process of the camera.
Finally, we compare the image quality to a commercial SLR digital camera.


Jason Harrison with Ron Rensink, Michiel van de Panne, Kathy Bruggencate, and Ritesh Shah
Plausible Physics Meets Psychophysics
Location:  Imager Large (FSC 2330)

Many computer animation researchers are interested in achieving
accurate physical simulations of natural phenomenon while other
researchers are "simply" interested in achieving "physical
plausibility" in their simulations.  Since I've never been very good at
physics, I'm more interested the plausible approach as it also requires
us to know a lot about human perception, which leads to great demos and
talk material. I'll discuss some of the related research and a few of
the experiments run over the last year to determine limits on human
motion perception.  Eventually this work will allow us to more easily
hide artifacts of constraint satisfaction -- such as foot contacts --
within the "unnecessary" and "imperceivable" degrees of freedom,
leading to simulations that are physically plausible and computationally tractable.

Colin Swindells
TorqueBAR:  An Ungrounded Haptic Feedback Device
Location:  Imager Small (FSC 2333)

Kinesthetic feedback is a key mechanism by which people
perceive object properties during their daily tasks -- particularly
inertial properties. For example, transporting a glass of water
without spilling, or dynamically positioning a handheld tool such
as a hammer, both require inertial kinesthetic feedback.
We describe a novel ungrounded haptic feedback device, the TorqueBAR, that
exploits a kinesthetic awareness of dynamic inertia to simulate complex
coupled motion as both a display and input device. As a user tilts the
TorqueBAR to sense and control computer programmed stimuli, the TorqueBAR's
centre-of-mass changes in real-time according to the user's actions.


SFU Talks (3:45 - 4:45)  Location:  CICSR Board Room (CS 288)

Ted Kirkpatrick
The Effects of Operating System and System Load on Haptic Interface Performance

The quality of haptic display is determined by the rate at which the forces
are recomputed.  Typically, this is done in a high-priority loop executing
at 1000 Hz.  This rate is only nominal, however.  The design of the
operating system and the concurrent load imposed by other applications (or
other threads in the same haptic application) can cause the actual execution
rate to differ substantially from this nominal value.  I will discuss
measurements that Jason Sze and I have made on response times for a PHANTOM
running under Windows 2000 and XP.  I will show that certain system loads
can make the force computation highly erratic.  However, dual-processor
configurations essentially eliminate this source of jitter.

Maryam Samiei
Using Information Visualization techniques to Manage Email

Although email was originally designed as a communication application,
it is increasingly being used for task management, reminding, and
scheduling. Email users need help in organizing and structuring of
incoming and outgoing "information flow" into workable units. Only
advanced visualization methods can really help accomplish this. The
purpose of our visualization is to help manage email by displaying the
content of messages in detail while preserving the context overview and
presenting the relationships among messages.

Tony Wong
CZTalk

Online discussion and conferencing have become popular ways for people to
share ideas.  Unfortunately, existing software interfaces exhibit a number
of usability problems and these may result in impediment to discussion flow.
  In this talk I am going to describe CZTalk, a graphical tool for online
discussion and conferencing, which is designed to alleviate some of the
usability problems in current software interfaces.  Features of CZTalk
include: displaying messages in a network structure, allowing of multiple
message reply, visual organization of messages and detail-in-context displays.

Tom Calvert
Graphics Research at SFU Surrey

This talk will provide an overview of graphics research efforts at the
SFU Surrey campus.

FOOD!  BBQ!  (4:45 - 6:30)