Capital ships physics

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Turbo12
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Capital ships physics

Post by Turbo12 » Sun, 30. Oct 11, 01:52

I would like to make a suggestion regarding the implementation of this statement:
When flying closer to large ships, your ship (or the drone you are remote controlling), will gradually be drawn into the influence of that ship.
I would also like capital ships to force fast ships to slow down. This way the fast ship would be forced to spend more time strafing, enjoying the scenery, and be in range of point defenses!
The model of this influence could be in the form of friction from a fluid that moves with the capital ship. It tends to move the surrounding ships with it and also slows them down in relation to the capital ship.

And I imagine two ways of putting it in the game universe:
The first one involves having a capital ship equipment module, say "EM field generator", that creates this drag that diminishes with distance. You could upgrade both the distance and drag generated.
The second one, involves having big, globe-like perimeter shields, some hundred meters larger than the capital ship itself. Any ship closing in below a set speed could cross it without crashing into it. And once inside, it would be under the influence of this atmosphere, that would vanish if the shields are depleted. Of course, the fighters would be able to attack the capital ship bypassing perimeter shields!

What do you think?

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Post by Chris0132 » Sun, 30. Oct 11, 02:41

Er, wouldn't it just be much easier to extend the range of point defence guns?

Ships towing around a giant bubble of atmoshere would look kinda silly and be hard to justify.

bobxii
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Post by bobxii » Sun, 30. Oct 11, 05:15

Just call it a tractor beam field and you're golden. Good idea - it makes capital ships risky targets to try and take on, makes them less susceptible to missiles (at least missiles without Anti-Tractor Field Technology 3.4...) in the process - possibly enforcing the idea that little ships don't have any business taking down bigships without some serious work.

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Post by A5PECT » Sun, 30. Oct 11, 08:41

The way I interpreted the one of the dev's description (I'll try to dig up a link, it's somewhere on the forums) of the capital ship "gravity" system is that if a small ship wishes to interact with a large ship (attacking, docking, etc.), the small ship will establish the big ship as its "anchor," and the small ship's navigation and flight systems will make all maneuvers based off of the big ship as a sort of point of reference. It's not that the big ship actually generates a significant gravitational force towards the small ship, it's that the small ship changes its flight behavior to imitate it being anchored to the large ship.

The best analogy I can think of is a parent-child relationship between two objects in a 3D modelling program. The big ship is the parent, and the small ship is the child.

But you'd probably have to be familiar with 3D modelling programs in order to fully understand the analogy. :roll:

Anyways, that would mean that the small ship has control over "anchored" mode and "unanchored" mode. So if a fighter wants to attack a capital ship, it will enter anchored mode and begin its strafing runs. If the fighter just wants to fly past the capital ship without engaging it, the fighter will stay in unanchored mode and whiz by.


Edit: Huh. That gives an interesting gameplay possibility: a "gravity well" sort of device that forces nearby ships into anchored mode and doesn't let them out of a certain radius until the device is deactivated or destroyed. A tractor beam could be used to a similar effect on individual ships, too.

Ack! The possibilities are driving me nuts!
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Post by Deeparth » Sun, 30. Oct 11, 11:57

Or maybe its plain old gravity. Remember capships are very large and drones tiny. Gravity of the capship will have an influence on small drones in a 0g environment.

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Post by A5PECT » Sun, 30. Oct 11, 12:00

Deeparth wrote:Or maybe its plain old gravity. Remember capships are very large and drones tiny. Gravity of the capship will have an influence on small drones in a 0g environment.
I've shied away from that explanation ever since I saw the amount of "SPACE DOES NOT WORK THAT WAY" rhetoric it spawned on these forums. People just ended up talking about how unrealistic a ship of that (assumed) mass wouldn't significantly affect a smaller ship and blah, blah, blah. :roll:

When the debate first cropped up I remember one of the developers was quick to elaborate on the subject (though not completely) and try to make it clear that it wasn't actual gravity affecting the ships.
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Post by Deeparth » Sun, 30. Oct 11, 12:11

KloHunt3r wrote:
Deeparth wrote:Or maybe its plain old gravity. Remember capships are very large and drones tiny. Gravity of the capship will have an influence on small drones in a 0g environment.
I've shied away from that explanation ever since I saw the amount of "SPACE DOES NOT WORK THAT WAY" rhetoric it spawned on these forums. People just ended up talking about how unrealistic a ship of that (assumed) mass wouldn't significantly affect a smaller ship and blah, blah, blah. :roll:

When the debate first cropped up I remember one of the developers was quick to elaborate on the subject (though not completely) and try to make it clear that it wasn't actual gravity affecting the ships.
Thats strange as experimens show its possible(even in orbit around Earth).

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Post by EmperorJon » Sun, 30. Oct 11, 12:38

Let's assume Hull is directly proportional to how much mass an empty ship has, ok? And assume that a scout is going to have a mass of several thousand kg. A Discoverer has around 1000 hull, IIRC, and judging by its size in comparison to a spacesuit is about as big as a large family car. But wider.

So, let's say it weighs 5000kg, probably an underestimate.

So each 200 hull = 1000kg.

Now, a Titan has a hull of about half a million, IIRC.

So it's only 500 times as massive as a Discoverer!

Oh dear! :P
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Post by Dantrithor » Sun, 30. Oct 11, 12:49

Deeparth wrote: Thats strange as experimens show its possible(even in orbit around Earth).
It is, but only affects noticeably during long periods. With a minor calculation I could get the forces applied on the ships by gravity:

* asumming a 4Km*1Km*1Km capital ship and a 20m*5m*10M fighter, with the fighter at 1.01k above the center of mass of the ship. The average mass is calculated at 4.507 Kg/m^3 (titanium). Outrageously high, but this is made to show a point.

Capital ship mass: 18028x10^9 Kg
Fighter mass: 4507*10^3 Kg

Force exerted on each ship: 5312.7 N

Acceleration induced on the fighter: 0,0011 m/s^2.

This means, our tiny fighter would be indeed affected by the gravity field of the capital ship. And it would accelerate towards it at 0,0011 m/s^2, or more simply written, 1,1 milimetre/second^2. And this is considering both bodies to have -huge- masses (even if it's hull was made of pure titanium, the capital ship should have about 1/5th of this mass due to corridors and other materials used for electronics, fuel, air, ...)

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Post by A5PECT » Sun, 30. Oct 11, 12:58

And here we go...
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Post by Deeparth » Sun, 30. Oct 11, 13:19

Ah...ok...i took the masses much higher. Plus...i didn't take the acceleration into consideration...and i was taking the force in Newtons as kg :evil: :oops:

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Post by Dantrithor » Sun, 30. Oct 11, 13:30

KloHunt3r wrote:And here we go...
If we talk about gravity, we're talking about real stuff.

If X-Universe space is filled with energetically linked particles which exert force on their pairs and get paired between metals close enough, then I can live with it :lol:


EDIT: Wait. You assumed the masses would be much higher??? At most, it could be osmium-made cube, at 22,600Kg/m^3... but even then... :D

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Post by bobxii » Sun, 30. Oct 11, 16:50

Point is that gravity is extremely weak, far too weak to act as a tractor beam vs power vehicles.

Moving on....

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Post by caleb » Sun, 30. Oct 11, 17:08

I think the way Egosoft is doing it, is just to increase playability. To be able to fly a drone more freely without crashing so easily. Adding tractor beams, or tractor fields would probably complicate things a bit too much, and add many layers of computational work into every fight. That computational work has to come from somewhere, so they would have to give something else up to make that work without lagging the game...

So I would prefer it is not included. X games are not exact simulators anyway, so no need to go too deep into physics for it.

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Post by bobxii » Sun, 30. Oct 11, 17:28

Nonono, not actually doing any calculations, just checking "ship within X meters of BigShip... No.. .moving on...". Done.

Turbo12
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Post by Turbo12 » Sun, 30. Oct 11, 18:05

I think you are missing the two points of my first post.
The first one is, slowing fighters down when close to the surface of capships.
And the second, some ideas for where to start the interactions with the capship. Either gradually, as was already suggested, or inside a volume with a defined shape.
I also like the idea of small fighters being able to fly inside the enemy shields. And on the other hand, capships being able to protect smaller vessels with their own shields.

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Freeman_79
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Post by Freeman_79 » Sun, 30. Oct 11, 19:44

Leave these calculations to the big boys at NASA instead, and save us and Egosoft some headache :D

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Post by ragamer » Sun, 30. Oct 11, 21:58

Not going to enter into the usual "realism" theories this time (Gravitation is a long range force... You can't restrict its action to "just a few meters" without resorting to fantasy, aka SciFi)

I think some ppl is looking at the wrong side of things...

...My interpretation of why they want small ships to "glue" to the "big brothers" is to make "Trench Runs" possible with normal flight controls so big surfaces can become easily "horizons" for the small ships and the surface elements obstacles (and cover) to dodge (or hide behind) while dogfighting.

The purpose here is to allow close inspection of a surface in as easy way as possible, after all they have devoted a good portion of the new engine to give us detailed and meaningfull surfaces.

It's also a way to ensure you reduce the ammount of collisions and probably will also help escort formations as the parent ship (Very good analogy that one with the typical 3D modeller hychearchy) will transfer its movement to the whole array of small ships surrounding it meaning that relative distance will be very easy to keep and, OFC manual docking "on the move" will be possible without "Elite-hourly manual approaches" ;).

Depends on how "strong" the "glue" is... But if you can check Iwar2:EoC formations you will get an idea on how effective this way to proceed can be (It's unreallistic, I know, specially when you see whole formations moving as a single perfect rigid body). it helps TONS to deal with the real anoyances of space/flight sims were fleets are involved... The intraformation collisions (Specially when the pointman does alter its speed abruptly).

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Post by Bobucles » Mon, 31. Oct 11, 01:15

But it's not a tractor field.
It's not gravity.
It's not magnetism.

The best explanation is that the big ship becomes the "point of reference" for your tiny ship's maneuvers. Why would that ever be interesting? So you can do insane daring heroics, of course!

I think that Star Wars explains it pretty well
http://www.youtube.com/watch?v=DOFgFAcG ... re=related

Try doing that in X3, when the enemy ship is moving. It is insanely hard to avoid crashing and blowing up.

Chris0132
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Post by Chris0132 » Mon, 31. Oct 11, 01:18

Basically, when you're close to a ship, the ship behaves like terrain, its movement will cause you to track with it, such that it appears as though you're flying over stationary terrain, when in reality both you and the terrain are cruising through space.

So yeah, you can do trench runs basically.

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