rick@pangea.stanford.edu (Rick Ottolini) (01/16/91)
NASA in Mountain View California has been developing this application for many years. They are one the VR pioneers, doing research before there were cheap eyephones and 3-D graphics systems. VRs constructed by remote sensors are called "telepresence" in some of the literature.
uselton@nas.nasa.gov (Samuel P. Uselton) (01/16/91)
Some of the people in Mike McGreavy's group here at NASA Ames ARE working on a virtual reality explorer using sattelite photo data of Mars. Lou Hitchner is the person who has shown me demos. They are using a Stardent platform and various View Lab developed displays. Yes it is true that un-manned exploration generates MUCH more science per dollar spent. I don't think you can expect it to generate the excitement that manned flight does. Even expanding the base of "explorers" as widely as described in the previous post doesn't provide the same attention. The danger and risk are part of what grabs our attention. (How long do you spend watching someone *else* play video games? This would be very similar.) There is very little *scientific* justification for some of the more subtle body cues described in the post. I think that the virtual explorers are going to be highly trained scientists (at least some graduate work in most cases), they just won't need the physical attributes of the astronauts. ...but that doesn't make them good for our romanticized "hero" images. The equipment will be configured to give the explorer the information needed to make judgements of "interesting to explore with the robots" (or not). Extra stuff may find its way into one or two prototypes, for the sake of exploring the technology, but the sensations of landing a rocket or the sound of hypothesized wind over the cockpit don't really add to getting the job done. VR lends itself to very vivid fantasies. And they are a lot of fun. But we are trying to find places to apply the technology to get work done in a more efficient way than without VR technology. When real workstations are getting real work done, the marketing folks will get interested and economies of scale can help the price come down. The work context defines the kinds of interactions appropriate for multiple occupants, so we can avoid (for now) the difficult philosophical and sociological issues. Well, back to work. Sam Uselton uselton@nas.nasa.gov lurker at NASA Ames Research Ctr. employed by CSC working for NASA speaking for myself PS Creon Levit and Steve Bryson will be giving demonstrations of the prototype Virtual Wind Tunnel using a head tracked, boom mounted, stereo viewer from Fake Space Labs, at various Conferences this year. Stop by and say "hi". Mention this posting and get a free....what? Oh. Sorry..
frerichs@ux1.cso.uiuc.edu (David J Frerichs) (01/16/91)
A problem remains with the virtual exploration of Mars... The speed of light. No robotic exploration can be truly interactive at that distance, the lag time makes that impossible. telepresence sensations are possible but they would not be in realtime in the sense that what you see is what is happening on Mars at this instant. Which makes the idea that the poster of "virtual mars" introduced quite impossible. (at least my impression of what he was saying) But even delayed telepresence would be a good addition to any remote robotic probe... imagine flying over Jupiter... Saturn... Uranus seeing things as the voyagers did or with computer enhancement. That is something I would like to experience. [dfRERICHS University of Illinois, Urbana Designing VR systems that work... Dept. of Computer Engineering IEEE/SigGraph Looking for cyberspace? frerichs@ux1.cso.uiuc.edu Well stop your snivelin', son, frerichs@well.sf.ca.us you've been in here all along! ]
bungi@milton.u.washington.edu (Timothy Wood) (01/16/91)
In article <14441@milton.u.washington.edu> scarlson@csa1.lbl.gov (Shawn Carlson) writes: > ... > Suppose we begin our Martian adventure by deploying a few >satellites to take high resolution pictures of the entire surface >of Mars. ... >You are flying a simulator and exploring a >computer generated "virtual world" that blends those high >resolution satellite photos into moving 3-D images and is >therefore identical in every detail to the real Martian surface. It seems to me that in order to be even slightly interesting to the virtual explorers, one would have to be able to image the surface of Mars with realatively fine resolution no matter how far one was from the virtual surface. Mars has a mean radius of something close to 3,400km. This give a surface area of about 145.3E6 square kilometers (assuming Mars is spherical, the actual figure could be much higher, depending upon how 'bumpy' Mars is...) To obtain an even slightly usefull picture, let's say that we use 8 bits per square centimeter. The appoximate size of the file would be something like 116E15 bits. Too be _fun_ we would need to be working on a much smaller scale, say square millimeters. At this small of a scale, the slight fractal nature of the surface would cause the area mapped be be far greater than the spherical approximation, and the spherical approximation _ain't_ small ( 'bout 11.6E18 bits ). If this were a mere pleasure simulation, one could easily use a rougher scale and make whatever random bumps we wanted. My question is this, is it possible to access and image this much data at a rate that would be necessary for a good graphical simulation? --- Timothy Wood tjwood@wolf.cs.washington.edu ---
leech@cs.unc.edu (Jonathan Leech) (01/17/91)
In article <14505@milton.u.washington.edu>, frerichs@ux1.cso.uiuc.edu (David J Frerichs) writes: |>imagine flying over Jupiter... Saturn... Uranus seeing things as the voyagers |>did or with computer enhancement. That is something I would like to experience. JPL already does this, as witness "Miranda: The Movie" and a number of other short features with similarly exciting titles. They use photoclinometry to recovery topography from the images. Unfortunately the resolution of Voyager images is usually many kilometers, so the movies aren't all that impressive. What is impressive is how *quickly* they can process the data - within a day or two of receiving the image. Jon (leech@cs.unc.edu) __@/
hitchner@riacs.edu (Lewis Hitchner) (01/17/91)
As several respondents have noted, NASA has already begun
implementation of a "Virtual Mars" system. Mike McGreevy has publicized
the concept of virtual planetary exploration for several years in both
spoken (e.g., keynote speech at ACM's CHI '89) and published form.
We also have an on-going project (on-going in spite of recent federal
budget cutbacks in NASA's Mars-Lunar Initiative program) entitled
"Visualization for Planetary Exploration" that already implements many
of the concepts proposed by Shawn Carlson in his article. However, our
project is merely a prototype and the "reality" is somewhat limited due
to the limited resolution data currently available (digital elevation
data derived from Viking orbiter satelite imagery) and due to the limitations
of current display technology and graphics hardware technology. But,
even given these limitations, we have been successful (at least, in our
opinions) in demonstrating that virtual planetary exploration is feasible
-- in a limited way today, and in a much more realistic way in the not too
distant future. The system we are developing is intended for use by
research scientists, such as the NASA, USGS, and university planetary geologists
who are funded by NASA to study geological features of the planets (and, I might
add, who have been doing so for a number of years using both remotely gathered
satellite data as well as first hand data collection at terrestial study sites
similar to Martian terrain -- Death Valley, and Antartica). Some initial
presentations of our system to some of these people have indicated that they
feel such systems will be very useful in their research (however, they also
strongly support the need for human presence for examining micro-features).
A few extra comments:
- Carlson and one of the follow-up'ers referred to data resolution and the
quantities needed, storage problems, etc.
Our data is quite low resolution -- 1 km grid spacing, measured in meters
16 bits per elevation value. That's pretty crude when you want to see
things smaller than continents. BUT -- we have that data for the whole
planet. So, it amounts to nearly 1/2 GigaByte (we also have another
9/10 GByte of higher resolution digital imagery or texture map data for
about 35% of the planet). By the way, this data is in the public domain
and is available from NASA Goddard's NSSDC (Natl. Space Sciences Data
Center).
What we are working with now is orders of magnitude less data than what will
be available real soon. Venus is now being imaged by Magellan's SAR
radar imager which is moderately high res. (I don't know figures, but
I believe it is somewhat comparable to USGS DEM data which is 150 meter
grid spacing, i.e., roughly 36 times the res. of our Viking Mars data).
In 1992 or later (depending on funding) NASA will launch the Mars Observer
satellite. MO has a laser altimeter that can directly measure surface
topography. It will be capable at its highest resolution of measuring
surface elevations to 1.5 meter resolution at similar spatial sampling
as that of Magellan I believe (maybe higher).
- regarding who might use such systems
Though I agree strongly with Carlson's feelings regarding virtual versus
real exploration, I'd take exception to his suggestions about how they would
be used and by whom. True, there is a great deal of educational and
entertainment potential for virtual exploration systems. However, our
"prototype" system with its limited performance requires about 1/4 million
dollars of computer equipment and highly trained technicians to operate it.
Hopefully, some day system development and operation cost will be much, much
lower. But, for the near future I can forsee such systems primarily used by
highly trained experts in planetary geology. We can't really afford to devote
use of such systems to non-specialists who spend "a week" being trained to
use the system (by comparison Shuttle astronauts spend 1 to 2 years training
for each mission, AFTER their years of general astronaut training, AFTER their
years of aviation or science training and education). Initially, at least,
I think virtual exploration systems would be most productive when used by
experts. For now, I think it would be possible to provide useful educational
or entertainment systems without the data accuracy requirements of a scientist
.
Current commercial systems can satisfy this audience by presenting good lookin
g,
although physically inaccurate, scenes at a much better cost/benefit ratio
than technically precise systems such as ours. Of course, as technology marche
s
on, we all hope and expect that such systems will become available to a much
less restricted audience -- school children, citizens, thrill seeking "virtual
explorers" -- for everyone to use.