Designing an AI for Computer Pilots. Help.

Designing an AI for Computer Pilots. Help.

Post by Piza » Mon, 27 Apr 1998 04:00:00



Hello,

I was wondering if there were any resources out there where i could find
information on how to design an AI for computer controlled spacecraft,
specifically for space combat.  I really dont know where to start at this
point.  I do know that i want to have accurate physics modeling (with the
exception that i 'might' ignore gravity wells and limit the scope to strict
0 g engagements).  What types of rules system should i use.  What type of AI
classification would this fall under? (i.e. state based?)

Essentially, I need to know what would a real space battle be like?  What
types of basic combat maneuvers apply in space?  Under what conditions would
/ should a ship attempt to flee?  Is fleeing even a feasible option in space
combat?  I suppose the only option is to attempt to outrun them?
Complicating this are the different types and sizes of ships.  For instance,
fighters will be engaging in close combat while huge Destroyer class
battleships could probably engage each other from many many miles away
(especially if they were using lasers and had very accurate targetting
systems).

Beyond that, there's mass combat.  This is way down the road, but given my
eventual implimentation of the above, i'd eventually hope to take the
simulation to this point of being able to place any number of ships from
various sides and have them go at it with all sides determining on their own
how they will formulate their attacks given a mission goal.   For instance,
if the goal were simply to annihalate the opposing forces the sides would
react one way... if the goal were to Capture a specific ship or Protect a
specific ship then they would / should use different tactics.

I really  need help designing this sytem.  Can anyone offer assistance?

 
 
 

Designing an AI for Computer Pilots. Help.

Post by John DiCamil » Tue, 28 Apr 1998 04:00:00



>I was wondering if there were any resources out there where i could find
>information on how to design an AI for computer controlled spacecraft,
>specifically for space combat.  I really dont know where to start at this
>point.  I do know that i want to have accurate physics modeling (with the
>exception that i 'might' ignore gravity wells and limit the scope to strict
>0 g engagements).

Well, I can give you a place to start: Flocking.  Do a web
search on "boids", or check out my web page for links to
flocking resources: http://www.irth.net/milo/ogr.htm

An interesting thing to note: most existing space sims use
different physics models for the player's ship and the AI
controlled ships.  The latest crop of sims (mostly still
in development) are moving toward using a more complete
physics model for all ships.  This poses additional problems
for the AI designer - you can no longer cheat and set the
ship velocity directly, the AI has to *steer* the ship using
a control system analogous to the player's joystick and
throttle.

Oh, it would also be worthwhile to look into digital control
systems.  For example, in my nascent space sim, the AI pilots
have a steering routine to seek a target.  This routine
computes the error between the target position and the AI
ship position, and seeks to minimize that error by steering.
This is a classic digital control system problem.  Incidently,
the same logic can be used to make effective AI guided missiles.

Quote:>What types of rules system should i use.  What type of AI
>classification would this fall under? (i.e. state based?)

Sure, you could use a state based rules system on top of
the low level flight behavior.  The rules engine would
decide when to attack and which target to attack, and
which threats to evade, and so on...

Quote:>Essentially, I need to know what would a real space battle be like?

Uh, no.  You want to know what a game or movie space battle
would be like.  Real world battle tactics are based on the
capabilities and limitations of real world weapons systems.
Well, there are no real world weapons systems that can be
used in meaningful space battles today.  So since you need
to invent ficticious technology anyway, you may as well make
it fun and exciting.

Quote:>What types of basic combat maneuvers apply in space?

It doesn't work that way.  Air combat BCM is all about making
the best possible use of an airframe's kinetic and potential
energy in an aerodynamic environment.  Most maneuvers in an
air combat sim involve trading altitude for speed and con-
trolling turn rate and radius to get within weapons parameters
without becoming a sitting duck yourself.  None of that applies
in space where you have no gravity, drag, or lift.

The remainder of ACM involves using teams of aircraft to
create a favorable tactical situation (e.g. drags, brackets,
the grinder, etc.).  Some of these may be applicable in space,
if you make the appropriate limitations on space craft speed,
agility, and sensor range.

Quote:>fighters will be engaging in close combat while huge Destroyer class
>battleships could probably engage each other from many many miles away
>(especially if they were using lasers and had very accurate targetting
>systems).

Another excellent reference on real world tactics is "Fleet
Tactics" by Hughes.  This covers the history of naval battle
tactics from the age of sail through the World Wars and into
the modern fleet.  Space operas usually model space combat
in two phases: fighter ships that emulate modern jet fighters
in space, and capital ships that emulate age of sail war
ships in space.

Quote:>Beyond that, there's mass combat.  This is way down the road, but given my
>eventual implimentation of the above, i'd eventually hope to take the
>simulation to this point of being able to place any number of ships from
>various sides and have them go at it with all sides determining on their own
>how they will formulate their attacks given a mission goal.   For instance,
>if the goal were simply to annihalate the opposing forces the sides would
>react one way... if the goal were to Capture a specific ship or Protect a
>specific ship then they would / should use different tactics.

Sure.  Of course, in this scenario you will be more limited by
the number of ships you can physically model and render than by
the performance of your AI routines...

Anway, that should get you started.  Good luck.

--

================================================================
John DiCamillo                             Fiery the Angels Fell

www.irth.net/milo                  Burning with the fires of Orc

 
 
 

Designing an AI for Computer Pilots. Help.

Post by Hugh Bothwel » Tue, 28 Apr 1998 04:00:00



> point.  I do know that i want to have accurate physics
> modeling (with the exception that i 'might' ignore gravity
> wells and limit the scope to strict 0 g engagements).

Depends on the scale you are working with.  If your ships are
interstellar, this might be reasonable; on the other hand, in-system,
using gravitational fields should be a very important part of strategy.

Quote:> Essentially, I need to know what would a real space battle
> be like?  What types of basic combat maneuvers apply in space?

Try reading "The Gripping Hand", "The Children's Hour" (from Man-Kzin
Wars 3 or 4, I think) by Larry Niven and Jerry Pournelle, "Through the
Breach" and "Fire Ships" (and maybe also "The Voyage") by David Drake.
Fred Saberhagen's Berserker series might also be useful, as would Greg
Bear's "Anvil of Stars" and maybe Vernor Vinge's "A Fire Upon the Deep".

Those should give you some basic ideas toward single-ship and multi-ship
combat in space, in atmosphere, and while grounded; also boarding
actions and orbital bombardment, and very different alien types.

Quote:> Is fleeing even a feasible option in space
> combat?  I suppose the only option is to attempt to outrun them?

... or switch to a trajectory which is too costly for them to follow; if
you are far enough ahead of them, you could use a moon-gravity-assisted
boost which skims the planetary atmosphere closely enough that by the
time they get there the planet blocks the chase trajectory.

It depends very heavily on your flight physics.  With current
technology, we are very fuel-limited; gravity boosts are a hugely
important source of energy, so much that non-assisted interplanetary
paths are prohibitively expensive in most cases.

Scifi-dom has come up with many work-arounds for this - Niven's fusion
spines and transit points, Alan Dean Foster's KK drive (really cute),
Drake's universe flipping, wormholes, ram drives, stasis fields,
hibernation ("cold sleep"), solar sails, etc, etc.  But basically they
fall into three categories: "fly faster", "teleport from here to there",
or "be patient".

Quote:> Complicating this are the different types and sizes of ships.
> For instance, fighters will be engaging in close combat

... also consider drones and parasitic outriders.

Figure, too, that at orbital velocities, ball bearings are potent
weapons.  In fact, _water vapor_ could do horrific damage (see "Startide
Rising" by David Brin, or "Songs of Distant Earth" by Arthur C Clarke
who uses a multi-megaton dust shield of water ice).

Quote:> while huge Destroyer class
> battleships could probably engage each other from many many
> miles away (especially if they were using lasers and had
> very accurate targetting systems).

Uh, "many miles"?  I think in most cases we are talking thousands or
tens of thousands of kilometers.  At these ranges, you can dodge laser
fire; closer, and it devolves into "who can slag who faster".

Also maybe look at MechWars (the original board-based role-playing game
game); I know there is a spaceship variant/derivative of it, and I'm
quite sure they'll have worked out extensive lists of ship types,
weapons, and tactics.  Surely you could draw ideas from some of this
material.

---------
Hugh Bothwell

 
 
 

Designing an AI for Computer Pilots. Help.

Post by Steven Woodcoc » Tue, 28 Apr 1998 04:00:00



: I was wondering if there were any resources out there where i could find
: information on how to design an AI for computer controlled spacecraft,
: specifically for space combat.  I really dont know where to start at this
: point.  I do know that i want to have accurate physics modeling (with the
: exception that i 'might' ignore gravity wells and limit the scope to strict
: 0 g engagements).  What types of rules system should i use.  What type of AI
: classification would this fall under? (i.e. state based?)

  The work being done for the SOAR/IFOR project (automated pilots for
combat aircraft) might be of use.  You can find out more at

           http://www.isi.edu/soar/soar.html

Steve, from the High Mountains of Colorado
"Don't Trust Anyone Under 14,000 Feet"
+=============================================================================+
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+=============================================================================+

 
 
 

Designing an AI for Computer Pilots. Help.

Post by Isaac K » Tue, 28 Apr 1998 04:00:00


In article <6i05jp$n1...@texas.nwlink.com>,

Pizaz <mi...@nwlink.comNOSPAM> wrote:
>Hello,
>I was wondering if there were any resources out there where i could find
>information on how to design an AI for computer controlled spacecraft,
>specifically for space combat.  I really dont know where to start at this
>point.  I do know that i want to have accurate physics modeling (with the
>exception that i 'might' ignore gravity wells and limit the scope to strict
>0 g engagements).

First off, you have a whole lot of issues to think about even
before worrying about computer AIs.  First figure out the human
side of the equation.

The big thing you have to figure out is the time/space scale.
You should realize that unless you're going to be flying
spacecraft next to black holes or near the surface of
planets, practically any playable realtime outer space game
can completely ignore gravity.

You can pretty much forget about realistic weapons, fuel,
and thrust considerations.  The time/space scales of such
things would lead to battles taking hours or days to
finish, and neither side would ever be in visual range of
the other (except through powerful telescopes).

So you'll just have to make up the numbers and go for
something playable.

There are basically three sorts of weapons with realistic
physics that lead to three sorts of combat maneuvering:

1. "Missiles".  These are long range disposable guided
   weapons which have superior thrust and delta-v than
   their targets, which ram the target and/or use
   relatively short range weapons.

   These weapons lead to combat maneuvering similar to
   current blue water navy ships.  Essentially, the
   maneuvers of the ships don't matter.  It's a battle
   of numbers as the "missiles" fly.

2. "Beams".  These are multi-shot weapons with a limited
   practical range, but with a high "muzzle velocity" so
   that the relative velocity with the target doesn't
   matter.  This includes lasers, particle beams, and
   possibly fancy projectile weapons.

   These weapons lead to combat maneuvering a little
   like WW1 style big gun ship combat.  Both sides
   try to maneuver their ship(s) to the most favorable
   combat range.  In a simple duel, the one with
   superior longer range firepower will attempt to
   keep its distance while the other one will attempt
   to close the distance or run away.

   With real life physics, these maneuvers will mostly
   be one dimensional--only thrusting directly towards
   or away from the enemy is relevant, much of the time.

3. "Bombs".  These are projectiles which may have
   superior thrust, but _inferior_ delta-v than their
   targets.  They ram the target and/or use short
   range weapons to damage the target.

   These weapons lead to complex combat maneuvering
   which has no terrestrial parallel, although it's
   sort of analagous to ancient ship combat mixed
   with air combat maneuvering.  In order to attack,
   the firing ship must either thrust towards the
   target to sling its "bombs" toward the target or
   wait for the target to thrust towards him.  In
   order to avoid counterattack, the firing ship
   must break off.

   In the case of a duel, this leads to two dimensional
   maneuvering as both sides dance around each other.
   In any other case, extremely complex 3D maneuvers
   result.

For playability, either option 2 or a mix of option
2 and 3 is best.  While option 1 is arguable most
realistic, it does mean maneuvers are largely irrelevant.
It turns the game into something like Missile Command.

I'd probably go with option 2 alone for an easy to
grasp, game.  I'd suggest option 2 with some option
3 weapons for advanced players.

Option 3 alone would lead to an incredible amount
of tactical richness, but most players would be
completely bewildered.  The only game I've played which
uses this is the Amiga version of Spacewar.  I'm used to
it, and it's very interesting playing against another
skilled player.  However, novices are just hopeless.
They just don't understand the implications of having
a low muzzle velocity compared to your thrust.  They
think that the typical engagement will be some sort
of "blow-through", but that's a mistake.  It would
simply lead to both sides destroying each other, since
neither can hope to get out of the way of the enemy's
fire.  The experienced player will simply fire its
torps toward the incoming novice and break off,
avoiding the novice's fire while he rams into the slow
wall of torps.

>What types of rules system should i use.  What type of AI
>classification would this fall under? (i.e. state based?)
>Essentially, I need to know what would a real space battle
>be like?

It depends upon the technology involved.  With most
plausible technology assumptions, it would be essentially
very long range and taking place over days, weeks, or
months.  So don't worry about that.

>What types of basic combat maneuvers apply in space?

It varies drastically depending upon what sort of
technology is involved.  Note that this is an area
in which very few people have seriously thought
things out.  For instance, most seem to think that
some sort of "blow through" maneuvers with thrusting
to reengage would be typical.  In fact, this would
be a mistake.  Under no circumstances will _both_
sides correctly want to reengage.  One side is
attempting to stop the other, and the other is
trying to break through.  However, the side that
is attempting to stop the other has made a big
mistake if it allows a "blow through" to occur in
the first place and it has the thrust needed to
reengage.

If it has the thrust needed to reengage after a
blow through, it certainly had enough thrust to
match velocities--and this would require less
fuel.  Matching velocities would allow them to
continuously engage the forces trying to break
through until they were destroyed, rather than
getting in some sporadic fire in a couple blow
through passes.

Of course, with most semi-plausible technology
assumptions, the real result of a "blowthrough"
pass is that both sides are obliterated, even
if one side is greatly inferior to the other.
That makes any possiblity of reengagement moot.

>Under what conditions would should a ship attempt to flee?
>Is fleeing even a feasible option in space combat?

It depends upon the strategic situation, and the
technology involved.  Assuming a very simple
strategic situation--this is a simple duel between
two private ships with captains who have a mortal
grudge against each other--a ship should flee
if it faces poor odds.  Fleeing is an option,
in the proper circumstances.  Typically, a ship
with superior delta-v can flee from a ship with
inferior delta-v and comparable thrust.

(For ships with equal average exhaust velocity and
equal payload mass, the one with more fuel has
superior delta-v.)

>I suppose the only option is to attempt to outrun them?

Not exactly,  In space maneuvering, fuel is not a
limit on how far you can go, it's a limit on how
much you can thrust.

>Complicating this are the different types and sizes of ships.  For instance,
>fighters will be engaging in close combat while huge Destroyer class
>battleships could probably engage each other from many many miles away
>(especially if they were using lasers and had very accurate targetting
>systems).

How realistic do you want to be?  You should realize that
even a 20mm airplane gun could be very accurately fired
over many miles in space.  There isn't any air to mess
with the aim, and no gravity/ground to limit how far the
shells go.

Now, there are a whole lot of non-intuitive issues with
lasers (in particular, the ways in which they may do
damage), but here's a single number on the matter of
range.  The 4m diameter Star Lite high power laser which
has already been fired on the ground has an estimated
practical range in space of more than 5000km (the
actual limit is classified).

>I really  need help designing this sytem.  Can anyone offer assistance?

Well, thoughts on realistic space combat is a hobby of mine.
--
    _____     Isaac Kuo k...@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
 __|_)o(_|__
/___________\ "Mari-san...  Yokatta...
\=\)-----(/=/  ...Yokatta go-buji de..." - Karigari Hiroshi
 
 
 

Designing an AI for Computer Pilots. Help.

Post by Steven Woodcoc » Tue, 28 Apr 1998 04:00:00



:>Essentially, I need to know what would a real space battle be like?

: Uh, no.  You want to know what a game or movie space battle
: would be like.  Real world battle tactics are based on the
: capabilities and limitations of real world weapons systems.
: Well, there are no real world weapons systems that can be
: used in meaningful space battles today.  So since you need
: to invent ficticious technology anyway, you may as well make
: it fun and exciting.

  This is not at all true...I speak from the point of view of somebody
who has done space-based weapons research and simulations.

  A lot of today's weapons systems, from simple projectile weapons
(machine guns, cannons) to nukes are quite suited to space use.  In
fact nukes are GREAT weapons for destroying large masses of enemy
ships (as I believe one Wing Commander addon pack demonstrated).  If
I'm being chased and can afford to do so, I could easily drop a nuclear
package behind me in orbit and prime it to detonate when my opponent
comes within range.  Orbital mechanics being what they are it would be
VERY expensive for him to avoid such surprises, and the resulting
near-burst EMP would wreak havoc with his electronics.

Steve, from the High Mountains of Colorado
"Don't Trust Anyone Under 14,000 Feet"
+=============================================================================+
|                                                           _                 |
| Steven Woodcock                                     _____C .._.             |
| Hired Gun, Gameware, 3D, and AI                ____/     \___/              |
| Wyrd Wyrks Consulting                         <____/\_---\_\    "Ferretman" |
| Phone:   719-392-4746                                                       |

| Web:     http://www.concentric.net/~swoodcoc/ai.html (Dedicated to Game AI) |
| Disclaimer:  I might work for Real3D Inc., but *speak* for them?  Nah...    |
| Lead Developer:  Behind Enemy Lines (Sega)                                  |
+=============================================================================+

 
 
 

Designing an AI for Computer Pilots. Help.

Post by John DiCamil » Wed, 29 Apr 1998 04:00:00




>> point.  I do know that i want to have accurate physics
>> modeling (with the exception that i 'might' ignore gravity
>> wells and limit the scope to strict 0 g engagements).
>Depends on the scale you are working with.  If your ships are
>interstellar, this might be reasonable; on the other hand, in-system,
>using gravitational fields should be a very important part of strategy.

Eh.  Orbital mechanics in space combat?  With a minimum
energy Earth/Mars transfer orbit taking six to nine months
of real time?  Sounds a bit...dull.

Quote:>> Essentially, I need to know what would a real space battle
>> be like?  What types of basic combat maneuvers apply in space?
>Try reading "The Gripping Hand", "The Children's Hour" (from Man-Kzin
>Wars 3 or 4, I think) by Larry Niven and Jerry Pournelle, "Through the
>Breach" and "Fire Ships" (and maybe also "The Voyage") by David Drake.
>Fred Saberhagen's Berserker series might also be useful, as would Greg
>Bear's "Anvil of Stars" and maybe Vernor Vinge's "A Fire Upon the Deep".

Vinge has a peculiar, but interesting take on FTL combat using
a system of micro jumps (essentially, turns) every few milliseconds.
The ships fire sub-light missile drones at each other across
space-like distances.  It is all a matter of synchronizing the
jumps so that your missiles happen to occupy the same volume
of space-time as your target between jumps.

Quote:>you are far enough ahead of them, you could use a moon-gravity-assisted
>boost which skims the planetary atmosphere closely enough that by the
>time they get there the planet blocks the chase trajectory.

Ah, technically that's an "angular-momentum-assisted boost".
The moon's gravity gets you both coming and going so there
is no net gain.  The benefit comes from borrowing some of
the moon's angular momentum as you approach it, slowing the
moon down in its orbit, while speeding you up.

--

================================================================
John DiCamillo                             Fiery the Angels Fell

www.irth.net/milo                  Burning with the fires of Orc

 
 
 

Designing an AI for Computer Pilots. Help.

Post by John DiCamil » Wed, 29 Apr 1998 04:00:00




>>I was wondering if there were any resources out there where i could find
>>information on how to design an AI for computer controlled spacecraft,
>>specifically for space combat.  I really dont know where to start at this
>>point.  I do know that i want to have accurate physics modeling (with the
>>exception that i 'might' ignore gravity wells and limit the scope to strict
>>0 g engagements).
>Well, I can give you a place to start: Flocking.  Do a web
>search on "boids", or check out my web page for links to
>flocking resources: http://www.irth.net/milo/ogr.htm

Oops, that should be:

http://www.irth.net/milo/3dgames/ogr.htm

--

================================================================
John DiCamillo                             Fiery the Angels Fell

www.irth.net/milo                  Burning with the fires of Orc

 
 
 

Designing an AI for Computer Pilots. Help.

Post by Randolph M. Jone » Wed, 29 Apr 1998 04:00:00



>   The work being done for the SOAR/IFOR project (automated pilots for
> combat aircraft) might be of use.  You can find out more at

>            http://www.isi.edu/soar/soar.html

Thanks for the plug.  I just wanted to chime in that the above
URL is a good "jumping off" place to a variety of research projects
using the "Soar Architecture for Cognition".  The central page
for the Soar/IFOR project is at:

   http://ai.eecs.umich.edu/ifor/

Note that some of the links from this page are password-protected,
due to government requirements, but you can usually get access to
them if you have a "legitimate" reason.

Randy

 
 
 

Designing an AI for Computer Pilots. Help.

Post by Randolph M. Jone » Wed, 29 Apr 1998 04:00:00


I think these are some pretty interesting questions, especially
if you are talking about "realistic" physical modeling of what
space combat would be like.  My impression of most "space fighting"
games is that they are not much like the real physics at all.

There was a video game back in the 70s (I think called "space war")
that used realistic gravity and near-zero friction for battling
between two space ships.  Also, the classic "asteroids" game might
give some idea of what high-speed battle maneuvering in space might
be like.

In air-to-air combat in the earth's atmosphere, a key component
for success is "energy management".  There is a lot of trade off
between potential energy (altitude) and kinetic energy (speed),
and if you ever let you total energy fall too low during a battle,
you are probably in trouble.  In space, you're basically not going
to have any potential energy without gravity.  In addition, with
littl-to-no friction, the physics of quick turns is not going to
be the same.  If you're going fast enough to keep the other guy
from shooting you, it's going to be very difficult to do any kind
of evasive maneuvering.  These same arguments apply to the
maneuverability of any weapons you might employ.

All of this is going to make fuel even more important than it is
in "earth-atmosphere combat", because using fuel is basically the
only way you will be able to control your craft (without altitude,
friction, air-foils, etc.).  Thus, I expect successful space
combat would look quite a bit different from traditional "dog-fighting".
My guess is that battles would take place at very large ranges
and very high speeds, with not too much maneuvering.

However, if you can write a simulation with realistic physics,
that would be an ideal playground to see whether I'm right.

Randy Jones

 
 
 

Designing an AI for Computer Pilots. Help.

Post by David Rus » Wed, 29 Apr 1998 04:00:00




> > Essentially, I need to know what would a real space battle
> > be like?  What types of basic combat maneuvers apply in space?

> Try reading "The Gripping Hand", "The Children's Hour" (from Man-Kzin
> Wars 3 or 4, I think) by Larry Niven and Jerry Pournelle, "Through the
> Breach" and "Fire Ships" (and maybe also "The Voyage") by David Drake.
> Fred Saberhagen's Berserker series might also be useful, as would Greg
> Bear's "Anvil of Stars" and maybe Vernor Vinge's "A Fire Upon the Deep".

A *must* read is Harry Harrison's _To_The_Stars_ trilogy, particularly
to last book (_Starworld_, IIRC). Niven and Pournelle, while they are
very consistent in their constructions, "invented" technology to
enable the sociology of their milieu. Saberhagen's beserker's do use
some viable tactics with no magic technology active, but they never
seemed to really be properly thought out from the standpoint of what
would really be effective. I can't say anything about Drake, Bear, and
Vinge.

Harrison points out that (as Niven has pointed out in some of his
essays) that kinetic energy and orbital mechanics pretty much define
the battleground for space combat. In doing so, projectile weapons
remain as effective as ever, and in some respects are even more
effective. If you have some idea of the performance parameters of your
opponent's ship, orbital mechanics allows you to devise inescapable
traps.

Energy weapons also won't do it, because the distances are simply
too big. If your target is a light-second away (and earth-to-sun is
over 8 light-*minutes*), he just won't be where you're aiming. Your
only chance is a surprise attack, because he can dodge as long as his
delta-V holds out.

david rush

 
 
 

Designing an AI for Computer Pilots. Help.

Post by James W Sager Ii » Wed, 29 Apr 1998 04:00:00


Excerpts from netnews.rec.games.programmer: 28-Apr-98 Re: Designing an

Quote:> Ah, technically that's an "angular-momentum-assisted boost".
> The moon's gravity gets you both coming and going so there
> is no net gain.  The benefit comes from borrowing some of
> the moon's angular momentum as you approach it, slowing the
> moon down in its orbit, while speeding you up.

This could lead to amusing aspects in a game if heavenly bodies
are held accountable for their momentum.
Ie, 8,000 ships a day do a moon boost... How many
days until the moon drops onto earth :P
 
 
 

Designing an AI for Computer Pilots. Help.

Post by James W Sager Ii » Wed, 29 Apr 1998 04:00:00


Excerpts from netnews.rec.games.programmer: 28-Apr-98 Re: Designing an

Quote:> There was a video game back in the 70s (I think called "space war")
> that used realistic gravity and near-zero friction for battling
> between two space ships.  Also, the classic "asteroids" game might
> give some idea of what high-speed battle maneuvering in space might
> be like.

Yeah, actually, this would be my guess to.
So long as you're below .87 the speed of light.
I believe that if you had a low thrust
Ie 10x the acceleration of your car or something,
the game play would be like you stated with asteroids.
if you started to go REALLY fast because there is nothing
slowing you down and someone was pursing you, then
you and him would look like you're playing a game
of asteroids, to everyone else standing still, you'd
just look like a blur going by.  <shrug>
The only real problem I've found with making silly 2-d
space combat simulators is getting the turn rate set,
eg. the rate at which the engine's swing around or what not.
 
 
 

Designing an AI for Computer Pilots. Help.

Post by Chris Bur » Wed, 29 Apr 1998 04:00:00


Quote:> A *must* read is Harry Harrison's _To_The_Stars_ trilogy, particularly
> to last book (_Starworld_, IIRC).

You might also read Roger MacBride Allen's "The Torch of Honor" for some
interesting manuever and weapons ideas like fuel management, using a
fusion drive's plume as a weapon, and solar/planetary shadows among
others.

One of his big ships uses a non-orbital re-entry approach (basicly
over-taking the planet in its orbit) that is at least interesting.
Can't vouch for the math though.

Some other ideas I heard/read/dreamed:

Using a moon to place your ship/missle in a retrograde orbit for less
delta-v than launching against the planet's rotation.

Using a planet's atmosphere to kill enough velocity for an orbit, a la
Arthur C. Clarke's baloot in "2010"

Anti-satellite weapons can use the targets own velocity, i.e. they don't
have to have enough momentum to make orbit, just get high enough to put
a bunch of cubes/rocks/debris in the target's path when it gets there,
then fall back after doing thier work.

Anyway, my two cents

Chris

 
 
 

Designing an AI for Computer Pilots. Help.

Post by Gerry Qui » Thu, 30 Apr 1998 04:00:00




>Excerpts from netnews.rec.games.programmer: 28-Apr-98 Re: Designing an

>> Ah, technically that's an "angular-momentum-assisted boost".
>> The moon's gravity gets you both coming and going so there
>> is no net gain.  The benefit comes from borrowing some of
>> the moon's angular momentum as you approach it, slowing the
>> moon down in its orbit, while speeding you up.
>This could lead to amusing aspects in a game if heavenly bodies
>are held accountable for their momentum.
>Ie, 8,000 ships a day do a moon boost... How many
>days until the moon drops onto earth :P

Brian Aldiss wrote a story (it's in 'The Airs of Earth' collection) in
which a planet was used to brake huge starships.  They would link by
some type of tractor beam to stations on the planet, and when a
ship braked the planet would turn suddenly, and day turn into night.

Now I come to think of it... why did the planet slow down to its
normal speed again?  I must find the book and see if there was an
answer to this!

- Gerry

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