VisAD
Learn About VisAD in Course 35 at
Siggraph 98
We'll be teaching about VisAD in Course #35 at Siggraph 98, in
Room 312 ABC of the Orange County Convention Center in Orlando,
from 8:30 AM to 5 PM on Tuesday, 21 July 98. The VisAD segments
begin at 8:30 AM and at 4 PM. We'll also be in the Computer
Applications Lab (CAL) from 11:45 AM - 1:30 PM on Wednesday.
Misprints in August 1998 Computer Graphics article about VisAD
The VisAD article in the VisFiles column of the August 1998 issue of
Computer Graphics has incorrectly printed arrow characters ("->" and
"<-->") as underscores ("_"). Here is a correct postscript version of:
Introduction
VisAD is a Java class library for interactive and collaborative
visualization and analysis of numerical data. It combines:
- The use of pure Java for platform independence and to support data sharing
and real-time collaboration among geographically distributed users. Support
for distributed computing is integrated at the lowest levels of the system.
- A general mathematical data model that can be adapted to virtually any
numerical data, that supports data sharing among different users, different
data sources and different scientific disciplines, and that provides
transparent access to data independent of storage format and location (i.e.,
memory, disk or remote).
- A general display model that supports interactive 3-D, data fusion,
multiple data views, direct manipulation, collaboration, and virtual
reality.
- Data analysis and computation integrated with visualization to support
computational steering and other complex interaction modes.
- Support for two distinct communities: developers who create domain-
specific systems based on VisAD, and users of those domain-specific systems.
VisAD is designed to support a wide variety of user interfaces, ranging from
simple data browser applets to complex applications that allow groups of
scientists to collaboratively develop data analysis algorithms.
- Developer extensibility in as many ways as possible.
VisAD was written by programmers at the
Visualization Project
at the University of Wisconsin-Madison
Space Science and Engineering Center
(SSEC), and by programmers at the
Unidata Program Office.
How to get VisAD
The source code of VisAD is freely available as:
You may need to click on the jar file with the SHIFT button held
down to get your browser to load it. If you still have trouble,
get the compressed tar file. See the
README
file for installation instructions.
The VisAD Java Class Library Developers Guide is the key document
for understanding how to use VisAD. It is available in the following
forms:
Other doumentation includes:
VisAD is also available as jar files containing compiled classes.
The classes of all VisAD packages are available as
You may need to click on the jar file with the SHIFT button held
down to get your browser to load it. If you still have trouble,
get the tar file - it contains one file - the jar file. See the
README
file for installation instructions.
Prerequisites
VisAD requires Java 1.2 (at least jdk1.2beta3). Displays may be
generated with either Java2D (included in Java 1.2) or Java3D.
They are available from:
the Java Developer Connection.
If you are in Europe
The
Deutsches Klimarechenzentrum
has offered to serve as a mirror site for our software. The
VisAD files are available from
this ftp
directory.
Collaborative Application Example
Here's a screen snapshot of a collaborative GOES satellite
sounding analysis application using VisAD:
The GOES satellite sounding analysis application supports remote
collaboration. It serves as a good example of how to build
collaborative applications using VisAD and is freely available
including complete source code as:
You may need to click on the jar file with the SHIFT button held
down to get your browser to load it. If you still have trouble,
get the compressed tar file. See the
README.paoloa file for installation instructions.
Support for File Formats
VisAD includes support for accessing data in various file
formats, including:
- FITS
- netCDF
- HDF-EOS
- Vis5D
- GIF and JPEG
Here's an interesting astronomical image from a FITS file displayed
using VisAD:
Computational Steering Example
The 2-D shallow fluid model lets you experiment with physical
and numerical parameters of the simulation and visualize the
consequences. It is freely available including complete source
code as:
You may need to click on the jar file with the SHIFT button held
down to get your browser to load it. If you still have trouble,
get the compressed tar file. See the
README.aune file for installation instructions.
Equinox: an Information Mining Example
Equinox is an information mining tool that utilizes machine
intelligence applied to natural language processing to significantly
enhance the innovative discovery process. Equinox uses VisAD.
Custom Texture Mapping Example
Lutz Laemmer has created an
extension of DataRenderer for customized texture mapping.
Interactive Earth Globe Example
Steve Emmerson has created an interactive globe display of Earth
topography and bathymetry using VisAD. It is included in the
VisAD source distribution as the visad/examples/Earth.java
class. You'll need to download
the netCDF topography file
into your visad/examples directory (you may need to click on this
file with the SHIFT key held down to get your browser to save it
on your disk), then run:
java -Xmx64m Earth lowresTerrain.nc
Image Stretching Applet Example
Curtis Rueden has written an
image stretching
applet using VisAD.
Other Information
You may be interested in two papers presented at the January 1997
AMS IIPS conference:
- Java and the World Wide Web: The Right Choice for Interactive Systems
available as
postscript
and ascii
- A Java and the World Wide Web Implementation of VisAD
available as
postscript
and ascii
The earlier version VisAD, written in C, has been freely available for
years and also has a
web page.
Getting Help
There is a VisAD mailing list. To subscribe to it send an email
message to
majordomo@ssec.wisc.edu
with
subscribe visad-list
as the first line of the message body. You can also subscribe to
visad-list-digest if you only want a daily summary of messages to
visad-list. To unsubscribe, send email to majordomo@ssec.wisc.edu
with
unsubscribe visad-list
as the first line of the message body.
Check out
Unidata's visad-list archive.
To contact the authors...
Email can be sent to Bill Hibbard at whibbard@macc.wisc.edu.
Postal mail can be sent to:
Bill Hibbard
Space Science and Engineering Center
University of Wisconsin - Madison
1225 W. Dayton St.
Madison, WI 53706
If you create extension packages to VisAD we will be happy to add
links to your web page describing and serving your extensions.
Disclaimer
VisAD is free software and as such we do not provide real support
for it. However, we will be happy to answer short questions and/or
help with minor problems (preferably by email).
P.S.
We also have a home page for
Vis5D.