We have created a 3-D model of nearly two thousand galaxies that you can download
over the Web and view on your computer. To use this 3-D model, however, requires
that you have a "fast enough"
computer, install some software, and learn how to move around in 3-D. It
takes some work, but nobody said exploring the universe would be easy.
We'll try to walk you through the process in four steps.
Step 1 - VRML & 3-D on the Web
VRML is an acronym for Virtual Reality Modelling Language; it is usually
pronounced "ver-mul." It is a programming language used to describe 3-D
models, called "worlds." A VRML world file, which usually has the extension
".wrl", is text file of instructions (or a compressed text file), and thus
easily distributable over the Web. An international VRML standard has been
established so that any standard-conforming worlds can be viewed by any
standard-conforming VRML browser. VRML browsers are generally distributed
as plug-ins to Internet browsers, and most are free.
Beyond just VRML, you may encounter the term Web3D. Web3D encompasses
all sorts of technologies for distributing 3-D content over the internet,
including Java3D, MPEG4, and about 100 proprietary technologies from
100 different companies. To date (Nov 2000), VRML is the only Web3D
technology that is standardized, in widespread use, on several platforms,
and freely available. But who knows what the future will bring?
Step 2 - System Requirements
The universe is a big place. It is hard to squeeze it down to fit inside
a computer. It is even harder when you want to interact with that universe
In short, older computers are unlikely to be able to run this 3-D model.
Based on our (admittedly limited) testing, we recommend:
PC (minimum) - Pentium II 233 MHz, 64 MB memory
PC (recommended) - Pentium III 500 MHz, 128 MB memory, 3Dfx Voodoo
3 or NVidia TNT2 graphics
Mac (minimum) - not tested sufficiently
Mac (recommended) - G3, PowerPC 300MHz, 128 MB memory
*NOTE: Load times do not include the time required to download the
VRML world file across the internet, which is highly dependent on your
connection speed and on internet traffic.
Due to the very wide diversity in graphic cards and installed software on
computers, we know there will be conflicts and bugs out there—potentially
some serious ones that may affect how your computer operates. We can't fix
such bugs. We probably can't even give you good advice on such bugs. We just
created a VRML world. We have no control over the VRML browser or your
internet browser or your graphics card drivers. About the only advice we can
provide is to be sure that you are using the latest version of the plugin.
To learn more, go to known bugs within "Top Ten Things to Know About
Step 3 - Download a VRML Browser Plug-in
VRML worlds are viewed using a VRML browser plug-in to your internet browser.
There are many VRML browser plug-ins available, but we recommend CosmoPlayer
2.1. It is available for PCs, Macs, and SGIs as a plug-in to Netscape
Navigator and Microsoft Internet Explorer.
Please look at these Installation Notes
for tips on installing CosmoPlayer. Also note that CosmoPlayer was developed
a couple years ago and has not been updated. It has some bugs that we will
discuss in Step 4. Further, the Mac version was never fully released; it
was only released in "beta" version. Even with these caveats, we feel it
is the best VRML browser plug-in.
Step 4 - Top 10 Things to Know About VRML
Exploring space in 3-D is unfamiliar to most everybody. Even those who have
played hundreds of hours of Quake have been moving mostly in familiar 2-D
terrain: where there are floors that define 2-D levels and stairs take you
between levels. Intergalactic space has no floors, walls, or ceilings.
Everyone must learn to move around in 3-D, and here that means learning
to use a VRML browser plug-in. The link below is a quick start guide: the
ten things everyone must know to have success. It will get you up and running
with the least amount of pain. Learn these points, practice them, and you
are on your way to becoming a master of 3-D. The instructions on these pages
are customized to the CosmoPlayer 2.1 VRML browser plug-in, but the concepts
are applicable to all browsers.
The "Local Universe in 3-D" VRML world contains 1793 nearby galaxies and covers
a good fraction of the Virgo Supercluster, including the Virgo Cluster and the
Local Group of Galaxies. Our Milky Way Galaxy is located at the origin of the
coordinate axes, since it is our reference point.
Click on the image at left to download the "Local Universe in 3-D" VRML world.
After the file has been downloaded to your computer, you can expect it
to take anywhere from 15 seconds to a couple minutes to load the world
and the first graphics to appear on the screen.
The above link is to a compressed version of the VRML world. Almost all
VRML browsers can handle compressed files. If your browser complains that
the above file is not a VRML world, you may want to try downloading the
uncompressed version. But beware, the uncompressed version is 1.2 megabytes,
almost 10 times larger.
Look at a screen shot -
You can use the screeen shot image to adjust your monitor, so that you
can see all the details in the model. If you know how to adjust the color
curve (i.e., gamma), it can greatly help you see more range of detail.
Turn off the lights - If you turn off the lights in the room, you will
be able to see more in the VRML World. This is especially true because
space is black, and you need to see color contrasts against black.
Patience - On the mininum level computers, it will take some time between
when you click and when the computer responds. Don't try to move around
quickly. Move slowly, and learn by practice how fast your computer will
let you explore. Note that the more galaxies that are in view, the slower
the computer will go.
Viewpoints - Remember that viewpoints will take you automatically to interesting
places in the VRML world. If you get lost, disoriented, or want to get
someplace easily, use the list of viewpoints.