7 replies to this topic

[Stainless]

I have been designing the combat for my new game and so I have been thinking about space combat ... a lot.

I thought it would be a good discussion to while away the down time when technical support for everything is not available.

When it comes to space combat, we seem to have two models. One based on Star Wars, lot's of small agile ships dogfighting, and one based on Star Trek. Large powerful ships where the technology is king.

I don't think either is 100% correct.

Issues of scale

Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

A spacecraft passing Pluto gets detected by Earth's defenses. Travelling at the speed of light, it is still over 5 hours away from Earth. A laser fired at it would take over 5 hours to get there. So you would have to aim at an intercept point 2.5 hours away from the targets current position, you can do a hell of a lot of maneuvering in 2.5 hours.

So does that mean that space combat can only work at short ranges?

Well possibly, or it might just mean that lasers are only useful at short ranges. Guided missiles could easily be used at long ranges. It depends on the next issue.

Inertia issues

Spock: Have you disengaged the external inertial dampener?
Hikaru Sulu: [Embarrassed. Without looking at anyone, he punches in the correct sequence] Ready for warp, sir.


F=Ma is a bitch. You have a huge space craft, you need a huge force to move it. In space you have nothing to push against. A modern plane uses the atmosphere around it, without an atmosphere, it's useless.

NASA's Dawn spacecraft has just set a new record for acceleration of a space craft, it only took it's ion drives four days to go from 0-60 miles per hour.

Star Trek got around this issue by inventing inertial dampers, originally they where invented to explain how the crew of a spacecraft could survive the acceleration to warp speed, but they also help with acceleration issues while at sub-light speeds.

So if our game has this issue, then we need inertial dampers. However if we have inertial dampers, then it implies that our space craft can be incredibly agile. Firing a laser at short range now has no guarantee of hitting as the ship can dodge at the speed of light.

It also makes the idea of dogfighting redundant. What is the point of performing an immelman turn if the enemy can just move vertically up without taking it's nose off you.


Computer issues

"Forty-two," said Deep Thought, with infinite majesty and calm.”

So if we now have space craft whizzing around like flees on steroids, how the hell can we shoot them?

Well it's time to bring in computers. A computer can react a lot faster than a human. A computer could predict the position of a rapidly moving object and plot an intercept. However the target also has a computer, and it's trying to avoid being shot.

So does space combat come down to a decryption issue? If my computer works out which random number generator your computer is using in the evade sub-routine, can it negate that sub-routine and turn your shiny new ship into space debris?

So does space combat reduce to the player with the most powerful computer wins?

Kinda boring.

Damage issues

So this is it," said Arthur, "We are going to die."
"Yes," said Ford, "except... no! Wait a minute!" He suddenly lunged across the chamber at something behind Arthur's line of vision. "What's this switch?" he cried.
"What? Where?" cried Arthur, twisting round.
"No, I was only fooling," said Ford, "we are going to die after all.”

A spacecraft is a tiny bubble of life support in a vast ocean of nothing. A tiny failure nearly killed the crew of Apollo 13. What would a missile hit have done?

This issue is not just a problem for space games, how much fun would modern warfare 3 be if a single bullet killed you?

So we have deflector shields and hull plating and men who can heal themselves just by not being shot for a few seconds.

Realistic? Hell no, but it solves the problem. Is it enough?

I don't think so. I think we need to model some kind of intelligent damage allocation, response, and effect system.

Your shield emitter may be destroyed, but you can reconfigure the sensor grid to project a defensive shield, or something like that.

A naval vessel is probably our best model to use. Redundant systems, backups, damage control.



I hope this has given you something to think about while digesting huge quantities of Meleagris gallopavo.

Ok well I better go now, there's an infinite number of monkeys outside who want to talk to me about this script for Hamlet they've worked out.

[}:+()___ (Smile)]

Scale:
Yes, I think a laser is a short range weapon. For long ranges you need missiles, maybe even small automated kamikaze spacecrafts.
Also there is another scale issue: even in short ranges angular size of spacecrafts is tiny. You cannot directly visualize space combat at scale, you must use tactical monitors with scematic spacecraft view.

Inertia:
I think you can always limit inertial dampers to the desired level of operation. Say, it works only for max 100g, or can only reduce acceleration by factor 100.
Personally I prefer something like microwarps without inertial dampers: spacecrafts move slowly but can periodically make jumps. It also reduces scale issue and has many tuning parameters.

Computer:
Space combats have a tactical/strategic level: even if you can't hit enemy spacecraft with single laser, you can concentrate fire from several friend spacecrafts. Still most powerful computer wins.

[rouncer]

if you wanted to make it realistic theres no way youll ever get out of the solar system so dont be afraid to make things up, as long as its believable perhaps, little made up things here and there are a necessity.

[fireside]

Space games are kind of like fantasy, the rules don't have to totally make sense, they just have to be consistent and imaginable. First off, dog fighting is fun. It's ridiculous that you have to plan where the ship will be when a computer would do a much better job, but that wouldn't be fun.
Controlling the logistics of a large ship can also be fun in a management type of way. I'm not sure a smaller game could handle the scope of both types of game play. If you do small ships, I think it's necessary to be near planet terrain at times to break it up.

I have to say, I'm more of a sucker for the space dog fighting, but some management, like Privateer added to it to spice it up. Another game that really pulled me in was Homeworld, which was almost completely management but really interesting because I was collecting and building on such a grand scale. At that point, the time it takes to get from place to place makes the game more exciting because it's harder to predict what will happen. Relatively speaking though, a gamer isn't going to want to wait more than a few minutes to get from point a to point b no matter how vast and infinite space is.

[Stainless]

}:+()___ (Smile), on 25 December 2012 - 07:22 AM, said:

Inertia:
I think you can always limit inertial dampers to the desired level of operation. Say, it works only for max 100g, or can only reduce acceleration by factor 100.
Personally I prefer something like microwarps without inertial dampers: spacecrafts move slowly but can periodically make jumps. It also reduces scale issue and has many tuning parameters.

100G would not be enough for a warp, think about 0-N * C in a couple of seconds. I can't be bothered to work out the maths but its a LOT of g.

I am now thinking that instead of accelerating very rapidly, maybe they change some other factor in the equation. Make the mass really small or the time very long.

“Time is an illusion. Lunchtime doubly so.”

Quote

You cannot directly visualize space combat at scale, you must use tactical monitors with scematic spacecraft view.

I agree. I have already started coding a scaleable tactical display based on modified NATO symbols.

I have also given my objects a radar and thermal cross section (only 8 bytes for each, but better than nothing).

Radar is modeled on transmitted power, reflected power, range, ecm and receiver sensitivity.

At these scales the sensitivity has to be amazing.

“A hole had just appeared in the Galaxy. It was exactly a nothingth of a second long, a nothingth of an inch wide, and quite a lot of millions of light-years from end to end.”

rouncer said:

if you wanted to make it realistic theres no way youll ever get out of the solar system so dont be afraid to make things up, as long as its believable perhaps, little made up things here and there are a necessity.

Yes I agree, but the best games have a consistent logic to them that makes it easier to believe in them, The immersion you are aiming for when you write a game is harder to achieve when little things nag away at the sub-conscious.

“The ships hung in the sky in much the same way that bricks don't.”

fireside said:

I have to say, I'm more of a sucker for the space dog fighting,

Not in my current game, the issues with the input system make it impossible. You just won't be able to survive trying to dog fight with a TV remote.

I don't mean actually fight the TV remote, that would be a short fight with an obvious result. A trip to Maplin's to buy another.

“The bird that would soar above the plain of tradition and prejudice must have strong wings. ”

[Stainless]

I have implemented missile combat.

It works in the radiation area.. not very well put .. but I'll try and explain.

Each object has a thermal and radar cross section.

Sensors try and lock onto a target.

In the code, each element is a program that you run on your ships computer. Each one has parameters that change with versions of the software.

For example SEEK1 has a range of 3000 km and a strength of 0.25 SEEK4 has a range of 10,000 km and a strength of 1.0

The seek code queries the targets computer to see if it is running any ecm, again ECM programs have various parameters including range and strength.

So in the seek program they query the targets computer, it has ECM1. In the ECM1 code it works out the range between the target and the missile and scales the strength based on range. This gets returned to the seek code.

The seek code applies it's strength value to this and normalises the result to the range 0-1. It then generates a random number and if this is less than the calculated value, the seek program has won and the missile tracks the target.

If it loses, then it either flies straight on, or it tracks a false reading projected by the ecm (this is for large vessels, jamming a missiles guidance is not a lot of use if it just flies straight ahead and you ship is the size of a carrier) for small vessels that are moving, the cheaper ecm is fine.

So missile combat is in three stages.

1) Acquisition
The enemy attempts to get a missile lock on the target. (SCAN software fighting ECM software)
2) Track
The missile tries to home in on the target (SEEK software fighting ECM software)
3) Resolution
What happens when the missile gets to the target

The final stage is what I am working on now. I want ships to have POINTDEFENCE software which uses all the available ships weapons as a final last ditch attempt to destroy an incoming missile. Or specialist radar guided cannons specifically for this task.

I also want more expensive missiles to have ECCM ..... this is getting interesting

[fireside]

This sounds like a strategy game, then, where the players main choices are type of computer, type of missile, and placement of defense ships? The defense appears to be fully automatic.

[Stainless]

Almost, it's more like a RPG combat system.... think Blue Dragon type of thing