Star Maps

21 posts ยท Sep 9 1997 to Oct 28 2003

From: Kyle Klingler <kklinglr@f...>

Date: Tue, 9 Sep 1997 16:37:24 -0400

Subject: Star Maps

I bought a copy of the computer game Frontier: Elite II because the star maps
impressed me. There was a grid level plane with circles for stars when you
looked at the map from above. But when you rotated it using the mouse, you
would see that each star had a line going to the grid show whether it was "up"
or "down" from it and the distance from it. The rotation worked very smoothly.
At the time it seemed impressive. That and the fact it had over 2000 star
systems mapped out (not sure if all of the stars were real).

From: Joachim Heck - SunSoft <jheck@E...>

Date: Tue, 9 Sep 1997 16:58:18 -0400

Subject: Star Maps

> Kyle Klingler writes:

@:) I bought a copy of the computer game Frontier: Elite II because @:) the
star maps impressed me.... At the time it seemed impressive. @:) That and the
fact it had over 2000 star systems mapped out (not @:) sure if all of the
stars were real).

I would expect you could visit them all if that's what you mean.
Whether they were stars that are actually in the sky - I dunno.  I
haven't played this but I was a big fan of the original Elite and it
sounds like they turned that game's radar system into a starmap -
interesting idea. I still think Elite's 3D combat system was better than that
found in most modern video games. Maybe they patented the
stuff or something - can't think why else no one would have used it
since.

From: Robertson, Brendan <Brendan.Robertson@d...>

Date: Tue, 9 Sep 1997 19:12:41 -0400

Subject: RE: Star Maps

One reason I can think of why no-one else used the combat system, was it
is just too difficult to hit anything!!! Realistic I suppose, but at
relative speeds of 20000km/s, even facing the target is a challenge
against the lighter fighters.

(w) Brendan.Robertson @ employment.gov.au 'Neath Southern Skies

From: Donald A. Chipman III <tre@i...>

Date: Tue, 9 Sep 1997 20:13:02 -0400

Subject: Re: Star Maps

> At 04:58 PM 9/9/97 -0400, you wrote:

Actually, Elite had an infinite star system. What they did is set the
computer's random number seed to a predetermined number (I think it was
based on X/Y coordinates of the sector or something like that), rather
than using the system clock like most programs do. Then, it simply generated
the universe based on those values.   Provided that you re-use the same
seed, the computer will always "randomly" generate the exact same universe, on
the fly, and without taking up a ton of storage space. It's really a pretty
elegant way to do things, from a programming standpoint.

Take care,

From: Steve Pugh <steve@p...>

Date: Wed, 10 Sep 1997 06:50:55 -0400

Subject: Re: Star Maps

> Kyle wrote:

There were several problems with the Frontier star map. First it was very
shallow, all the stars were at most 10 (or was it 20?) parsecs above or below
the plain of the map.

Secondly, a lot of the stars were in the wrong place! Look at
Alpha/Proxima Centauri: it isn't even the closest star to Sol on that
map.

Thirdly, a lot of real stars got missed out and a lot of made up ones included
even in the regions near to Sol.

From: Phillip E. Pournelle <pepourne@n...>

Date: Mon, 11 Oct 1999 21:50:28 -0400

Subject: Star Maps

I'm very impressed by the work done by the gentleman who built the star maps
for the GZG universe. The impression I get is that the gathering of a number
of stars is based
on their 3-D positioning.  While a group of stars apear to be so far
apart as to denigh any sense of contiguency, in a three D view they actually
do.

Unfortunately, the three D view is not effective for a campaign map. Is it
possible to generate a 2D map, perhaps on a hex sheet, where there are
distortions of the star's actual position, but positioned to create a sense of
how far apart they would be for a strategic view?

From: Andrew Martin <Al.Bri@x...>

Date: Tue, 12 Oct 1999 16:57:21 +1300

Subject: Re: Star Maps

> Phillip Pournelle wrote:
Is it possible to generate a 2D map, perhaps on a hex sheet, where there are
distortions of the star's actual position, but positioned to create a sense of
how far apart they would be for a strategic view?

I don't know about a hex map, but certainly a point and line map could be
drawn for subsets of the stars. Each star empire could have it's own map. The
"capital" stars of each empire could then be placed on their own map. For the
point and lines map, there's an application in Sun's sample Java applets which
could be useful for a web based system. Unfortunately, I've forgotten the name
of the applet.

From: Ndege Diamond <nezach@e...>

Date: Mon, 11 Oct 1999 21:20:54 -0700

Subject: Re: Star Maps

> At 09:50 PM 10/11/99 -0400, you wrote:

If I may be so bold I would recommend you check out ChView. It is a small app
(267KB, some of the map files are bigger than the program itself!) that
aids you in viewing 3D starmaps.  The print-outs it produces are not
professional quality but you make up for it by being able to quickly change
the view angles and zoom levels without having to resort to editing the map in
a graphics program.

The ChView home page is at http://members.fcac.org/~sol/chview/  Map
files are also avalable from the site. You can edit the star data or just make
your own.

From: Nyrath the nearly wise <nyrath@c...>

Date: Tue, 12 Oct 1999 06:59:41 -0400

Subject: Re: Star Maps

> Phillip Pournelle wrote:

Yes, I'm the person in question who made the maps (and I am also a big fan of
your father's novels, BTW).

I used my homemade program to make the maps, available at
        http://www.clark.net/pub/nyrath/smapx.html
        for Win95/98.  It will make flat maps, but will also
        display in rotating 3-D.  I did try to make things so
        stars were close in 3-D, even though they look odd on
a flat map.

Alas, it is rather difficult to do what you ask, flattening

From: Thomas Anderson <thomas.anderson@u...>

Date: Wed, 13 Oct 1999 19:26:36 +0100 (BST)

Subject: Re: Star Maps

> On Tue, 12 Oct 1999, Nyrath the nearly wise wrote:

> > Phillip Pournelle wrote:

i've had a quick look at this; it looks rather keen. sadly, the only hard
info on the algorithm is a c program (c is a write-only language :(, and
it doesn't help that the programmer's first language is Dutch) so i have no
real idea how it works.

basically, Kohonen mapping can be used to 'flatten' a set of points in 3
dimensions to a set of points in 2 dimensions such that the distance relations
between them are more or less preserved. it can't be used to make a real 2d
map (where measured distance is proportional to real distance), but it can be
used to lay out points on a chart in such a way that jump paths (which are to
nearby stars) will tend to be to nearby points.

is there any chance Mr Crook will do any work on a 3d -> 2d flattener
himself? if not, i'll put this on my almost infinite pile of things to do.
actually, it turns out Kohonen maps have applications in visualising protein
structure, so i can sort of justify learning about them!

tom

From: Laserlight <laserlight@q...>

Date: Wed, 13 Oct 1999 20:19:21 -0400

Subject: Re: Star Maps

> > Phillip Pournelle wrote:

How many stars are you thinking of? If the whole
Nyrath-map, then no.  If you have a fairly small number of
stars, then yes, kind of.

You can determine which plane (x, y, z) has the smallest difference from
minimum to maximum value and make that your "z" on your 2D map, then just plot
your other two coordinates as the x and y and ignore the z.

Or you can use graduated circles to depict the Z. Say your
Z covers from +5 to -5 parsecs--use a large circle to
represent +5, a medium at 0, and a tiny one at -5, plus
intermediate diameters to taste. I don't much like this because I don't have
the patience to draw circles.

Or you can pick the three most important points on your map (in my case,
Alarish, New Arabia, and Huy Braseal, the latter because it's closest to
everything else), plot those three distances correctly, and fit everything
else in as best you can.

From: Tim Jones <Tim.Jones@S...>

Date: Thu, 14 Oct 1999 08:38:54 +0100

Subject: RE: Star Maps

> i've had a quick look at this; it looks rather keen. sadly,

Plus its a comment free zone.

From: Thomas Anderson <thomas.anderson@u...>

Date: Thu, 14 Oct 1999 12:55:04 +0100 (BST)

Subject: Re: Star Maps

> On Wed, 13 Oct 1999, Laserlight wrote:

> >> > Phillip Pournelle wrote:

in principle, the plane of projection needn't be any of the zy, xz or yz
planes (is that how you name planes?); they have no significnt physical
meaning, they're just convenient. thus, you could pick any plane and project
the 3d map onto that; that way, you could absolutely minimise the total
vertical height covered by the map. i'm not sure how you'd calculate which it
was, although some sort of 3D generalisation of linear regression (planar
regression?) might do the trick. i'm also not sure how you'd do the
projection. i suspect linear algebra is involved, and so my mind is refusing
to think about this any more until i've had lunch.

> Or you can use graduated circles to depict the Z. Say your

i like this idea - you could use this in concert with a snazzy
projection method for extra supa dope results.

also, for large maps, you could split the space into layers, and draw separate
maps for each layer. this may not be very usable, though.

> Or you can pick the three most important points on your map

one way to do this would be to pick a plane which passes through all three
points (in 3-space, there is exactly one plane which passes through 3
points [1]) and project onto that. this should be easier than the
full-blown height-minimiser.

i still think a Kohonen map is the way to go...:)

tom

[1] unless they're in a line

From: Samuel Reynolds <reynol@p...>

Date: Sat, 16 Oct 1999 09:34:54 -0600

Subject: Re: Star Maps

> On Tue, 12 Oct 1999, Nyrath the nearly wise wrote:

An alternative might be to do a direct planar projection, but to label or
otherwise mark lines between stars with their distances
(in parsecs, LY, jumps or jump-factors, etc.). That would require
only minor changes to a projection program (or perhaps none!).

- Sam

From: Samuel Reynolds <reynol@p...>

Date: Sat, 16 Oct 1999 09:41:12 -0600

Subject: Re: Star Maps

> in principle, the plane of projection needn't be any of the zy, xz or

To determine plane that will provide the least z-axis distortion
(i.e., the plane that is nearest to containing all the stars), by minimizing
the mean squared distance from a plane to the stars. Without actually doing
this, I think this would also minimize the
apparent errors in the x- and y-axis relative locations of the
stars. All inter-star paths not parallel to the resultant plane
would still be foreshortened, however.

- Sam

From: Indy Kochte <kochte@s...>

Date: Mon, 25 Oct 1999 08:50:47 -0500 (EST)

Subject: Star Maps

With the recent(-ish) discussion on star mapping that had been
going on here (and subsequently moved over to the gzg computer core list) I
thought some of you might be interested in knowing that National Geographic
put out a *very* nice Milky Way star map recently (I think last month's issue;
I just found it this
past weekend - that's how busy I've been, I'm months behind in
my magazine reading :-/ ). Within this double-sided poster are
relative positional maps of the stars within 20 ly of our sun
(I haven't cross-checked this to verify it is showing each and
EVERY star w/in 20 ly, but there's pleny shown so prolly close
enough). then our position within the Milky Way, then the pos-
ition of the Milky Way within the Local Group, and the Local Group's position
within the Supercluster [of galaxies], etc.

As I said, very nicely done map. I believe you can order these maps directly
from National Geographic (at www.nationalgeographic.com)

Anyway, just fyi, for those mapmakers and interested parties in seeing this
sort of stuff.

Mk

From: Michael Llaneza <maserati@e...>

Date: Mon, 25 Oct 1999 07:57:43 -0700

Subject: Re:Star Maps

At 8:50 AM -0500 10/25/99, "The ledge is a favorite hangout for
> pigeons. The white stuff wrote:

There's also a 3D tour of the solar system (requires a Windows only plugin) at
National Geographic's website.

From: Matt Tope <mptope@o...>

Date: Mon, 27 Oct 2003 15:44:49 -0000

Subject: RE: Star Maps

Tim, is this what you were after?

http://www.idcproductions.com/SFBmain.htm

Regards

From: Flak Magnet <flakmagnet@t...>

Date: Mon, 27 Oct 2003 13:52:56 -0500

Subject: Re: Star Maps

Yes, that is it exactly, that you muchly!

--Tim

> On Monday 27 October 2003 10:44 am, Matt Tope wrote:

From: Flak Magnet <flakmagnet@t...>

Date: Mon, 27 Oct 2003 14:15:36 -0500

Subject: Re: Star Maps

Erm, "thank you muchly", rather...

> On Monday 27 October 2003 1:52 pm, FlakMagnet72 wrote:

From: Matt Tope <mptope@o...>

Date: Tue, 28 Oct 2003 10:29:01 -0000

Subject: RE: Star Maps

Mulchy is good, helps the roses grow...

Cheers,

Matt

[quoted original message omitted]