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<title>Re: [simpits-tech] Falcon views 360? (Long)</title>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>If you go over to L3’s web site (and
there is a similar, if not the same picture on simpits), they have a setup up
that is essentially a large faceted canopy. The front is a pentagonal
screen and the sides are rectangular and reach back past the pilot. I’m
hoping that if the new Falcon ever does come out, it would offer a scalable
image to attempt something of this nature. Granted, you would spend a
pretty penny on 5-6 projectors (not to mention the computers and bandwidth
needed to drive these), but if you could approach a 360 degree image as well as
one that covers the sight lines laterally below the canopy sill, it might just
be worth it. I may even consider MSFS200x if I could have this scale of visibility.
Nice explanation Marv.</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Jay</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b>
simpits-tech-bounces@simpits.org [mailto:simpits-tech-bounces@simpits.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Marv De Beque<br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, October 16, 2003
6:27 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Simulator Cockpit tech list<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [simpits-tech] Falcon
views 360? (Long)</span></font></p>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal style='margin-right:0in;margin-bottom:12.0pt;margin-left:
.5in'><font size=3 face=Verdana><span style='font-size:12.0pt;font-family:Verdana'>1:
Version of Falcon (or other flight sim software) to support multiple
monitors (either directly or through some sort of network). The narrow
FOV will need a way to be switched to any desired panned position rapidly.<br>
<br>
2: Displayable dome (Can be partial or full depending on your needs).
Probably 15 feet in diameter is the minimum size.<br>
<br>
3: Two projectors. You will need some optics to narrow the field of
view for one and a fish eye optic lens for the wide view. Edmund
Scientific, here we come!<br>
<br>
4: 2 Optical grade flat mirrors. One is stationary, the second
would be mounted to a two-axis gimbal controlled by high-speed servos.
Basically, the pair form a periscope so that the narrow view projector
image can be aimed at the pilots field of view. This can be done without
the mirrors, but that would require the projector be mounted on the gimbal.
The problem with that approach is mass. Rapid movements would
require overcoming larger amounts of inertia and can result in over shoot or
ringing as the system stops. The ringing could be computer dampened, but
the mechanical stress would most likely be detrimental to the projector and the
bulb.<br>
<br>
5: Head Tracking hardware and a PC to control the servo actuated mirror.
Software to drive the servo system.<br>
<br>
Obviously, the dome would require a lot of space, but you could reduce the size
by limiting the view area to whatever works well.<br>
<br>
A slight modification of the above plan would be to reduce the wide angle
projector to something closer to 180 degrees or less. The second
projector would also be slaved to the narrow view projector’s image so it
would move in tandem.<br>
<br>
A low tech solution would be to use one projector and project the image where
the pilot is gazing. You loose peripheral images, but you save buying two
projectors. This may be a good plan for getting started. Getting
the head tracking and image projection working would be the lion’s
share of the technical hurdles out of the way. Adding a second projector
would be relatively easy.<br>
<br>
However, all of those ideas require a large room for a dome of some sort.
I don’t have a theater in my home!<br>
<br>
Another thought would be to project the image from above onto a cockpit canopy
that is translucent. This would reduce the amount of room size required
and reduce the amount of swept area for the second projector. One problem
with this approach would be a loss in depth perception. Your focal
distance would be very close. I don’t know how that would be
interpreted, but I would not think that it would be too bad. Still,
I’ll bet that it will look like someone has projected an image onto your
canopy, rather than an out the window view. Might be an interesting
experiment.<br>
<br>
Projection onto a canopy has another interesting challenge. The image
would need to be projected from at least two positions and the focal length
would need to be a function of angular position. When you project onto a
concaved curved surface from the inside and the radius of the curved surface
coincides with the optic lens, the focal length is the same at every point on
the sphere’s surface. Think of a very large ping pong ball with a
projector at the very center. Now, if you project from the outside of
that ball onto a convex surface, the focal length changes over the surface of
the sphere you project onto.<br>
<br>
I think this can be compensated for optically. You will need to do this
anyway since the image will also be grossly distorted. Imagine trying to
project a uniform grid (like the Earth’s latitude and longitude lines)
from inside a ball. If it was projected from the inside radius, as I
cited in the first example, the grid would look perfectly uniform. When
projected from the outside onto a sphere the grid would be highly distorted.<br>
<br>
Since a canopy is not a perfect sphere, but an irregular shaped object, the
distortion would be even more complex. Again, if you can model the
surface to be projected onto mathematically, then you could, in theory, grind a
special lens or mirror to compensate for this. Well, to a point.<br>
<br>
Additionally, you need to also add either additional projectors to cover the
outside surface or beam splitters to split off the projector’s output and
project from multiple angles onto the canopy. Why do we need more
projectors? Well the best coverage you can get for illumination of a
sphere from the outside is no more than half a sphere. Even at that, the
edges have a high degree of distortion. Since a full cockpit view is
technically larger than 1/2 a sphere, multiple sources are the only
answer.<br>
<br>
A compromise would be to construct a canopy that is faceted and project
separate images onto each flat facet. Maybe 4 to 6 projectors could cover
a very large field of view. At some point with enough facets, the
projector resolution for a given area or facet becomes good enough that the
head tracking is no longer needed. Flat surfaces provide a wonderful way
to relieve the problem of complex optics, but you still have seams between the
facets.<br>
<br>
Another problem with projecting onto a surface that is in close proximity to
the pilot is the parallax effect. When you view some object out the
window and the observer moves slightly side to side, the object moves relative
to the window. You loose this with an image that is close to your field
of view. Head tracking can be used to apply an image shift to compensate
for the movement and would give back that illusion of the object’s
intended distance. I think that would greatly reduce the painted on my
canopy feeling.<br>
<br>
Personally, I think that there may be some advantages to this system.
While more projection systems are required, the space needed to do it
would be much less than a full or even a partial dome! You also could
eliminate some of the complexity of having head tracking.<br>
<br>
Further down the road would be the use of VR goggles. As we mentioned
before, the current resolution is poor and you don’t have the ability to
see real objects such as your real cockpit. However, that problem is not
really a technological barrier that hasn’t already been solved.
There has been work already for specialized application (such as surgery)
where both real world and virtual images are mixed. This can be done via
small cameras on the glasses for the real world view or a complex shuttering
mechanism that allows external light to pass through selectively. Both
systems would require a computer to have a programmed field of view that is
predetermined (such as the cockpit rails where the canopy intersects).
Either pattern recognition or head tracking system would determine where
the virtual and real world intersect.<br>
<br>
Obviously, there are cost issues with this since the technology is new and high
resolution images for VR goggles are very expensive. If the market for
this type of technology expands, the cost may someday drop to a point where we
could afford it.<br>
<br>
However, today we are seeing a significant drop in the price of projectors and
a new family of projectors that use DLP. DLP essentially is a high
density array of miniature mirrors that are electronically steered by a silicon
chip. Rather than pass light through a LCD, light is reflected off of the
DLP mirrors which are precisely positioned electronically to produce an image.
The result is a much, much improved image brightness. And, no smoke
is required. :-)<br>
<br>
Marv<br>
<br>
<br>
On 10/14/03 9:56 PM, "JL" <Johnlimd@bellsouth.net> wrote:</span></font></p>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-left:.5in'><font size=3 face=Verdana><span
style='font-size:12.0pt;font-family:Verdana'>What I proposed is not a perfect
solution (you would have to fly a real jet), but think of the possibilities.
First, you only need two views. You could easily build this system
today for under $3,000. Probably under $2,000. The projectors are
80% to 90% the total cost. What are the alternatives? Placing
a half dozen monitors around your desk? What about all those seems?
How much area can 6 monitors really cover? VR goggles?
Good field of view, but lousy resolution. You get 60 degrees or so
of FOV at 1024 by 768 pixels on a really good pair. Most goggles have
mush less resolution and still cost some bucks. Of course if you have
$100,000 you buy what the military uses. Add to that you can’t see
your cockpit (which you just spent years putting all that detail into).
Would you rather flip a virtual switch or a real one you can feel?<br>
<br>
Marv<br>
</span></font><font size=2 color=blue face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:blue'><br>
</span></font><font face=Verdana><span style='font-family:Verdana'><br>
<br>
Alright Marv!<br>
I dare say that many of us would love to see your idea work for $2000.<br>
I'm in, even at a cost of $3000. Who else is in?<br>
<br>
Design and implementation plan? -- All smoke and mirrors??<br>
Doesn't Falcon 5 need to be written to support the low rez 360 view?<br>
<br>
H</span></font><font size=2 color=blue face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:blue'> </span></font><font face=Verdana><span
style='font-family:Verdana'>ere's another idea.... With projectors
getting so lightweight (< 3 lb) and relatively less expensive, how about
mounting one on your helmet so it paints hi rez where you're looking.</span></font><font
size=2 color=blue face=Verdana><span style='font-size:10.0pt;font-family:Verdana;
color:blue'> </span></font><font face=Verdana><span style='font-family:Verdana'>Gives
new meaning to "Hot headed pilot"<br>
<br>
B</span></font><font size=2 color=blue face=Arial><span style='font-size:10.0pt;
font-family:Arial;color:blue'> </span></font><font face=Verdana><span
style='font-family:Verdana'>ut seriously, can you enumerate the steps
that need to happen to make this reality? (not that you don't have enough to
do... ;- )<br>
<br>
John</span></font><font size=2 color=blue face=Verdana><span style='font-size:
10.0pt;font-family:Verdana;color:blue'> </span></font></p>
</blockquote>
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