Oolite Bulletins

Ahruman wrote:

My guiding rule when it comes to things like the flight model are: “for games that make more sense than Elite, see: games that aren’t Oolite.”

It does make sense, for a given value of "sense". My preferred technobabble explanation involves the assumption that the all the ship's drives are essentially the same thing: the Witchspace broomstick.

A broomstick drive, of itself, can propel a ship at relativistic speeds (e.g. 0.35C) by manipulating the localised gravity field. The blue glow from the engines is not caused by thrusters: it's Cherenkov radiation produced by the mechanism of the drive -- hence no fuel is required for in-system travel, and the ships exhibit non-Newtonian flight characteristics.

When local spacetime is flat enough, e.g. when the ship is far enough away from a sufficiently large gravitational field and/or another broomstick drive (both of which distort spacetime), a broomstick can achieve speeds greater than C, but still too low for practical interstellar flight: this is the Torus jumpdrive.

When quirium, a stable transplutonic element naturally occuring in tiny quantities within the coronae of stars, is pushed through a broomstick, it can produce a temporary wormhole, whether or not other masses or broomstick drives are in the vicinity. More quirium = longer wormholes, up to the disputed "Q limit" of 7 light years (some theories suggest that other, as-yet undiscovered, stable transplutonics may be able to generate longer wormholes).

When smaller amounts of quirium are forced through a broomstick in a controlled flow, the drive can achieve speeds greatly in excess of the normal functioning, but lower than the Torus effect. Because of the quirium, this works, again, whether or not any large masses or other broomsticks are around. The amount of Cherenkov radiation produced is, of course, much larger -- hence the powerful purple glow emanating from a ship using fuel injectors.

A broomstick drive is, as the name implies, long and thin -- the superficial resemblance to an actual broomstick is what gives "Witchspace" its name -- and has to run down the z-axis of the ship. Because of Drivel's Law, a ship can be easily spun around this axis, or pitched up and down -- but it's extremely difficult to drag it laterally from side to side. Ship designers and pilots, though, are used to working with these small limitations, given the huge benefits of witchdrive technology. Thrusters, reaction mass and the like are, in the Ooniverse, massively outdated concepts: adding them to modern starships would be like putting sails on an aircraft carrier.

Disembodied wrote:

A broomstick drive, of itself, can propel a ship at relativistic speeds (e.g. 0.35C) by manipulating the localised gravity field. The blue glow from the engines is not caused by thrusters: it's Cherenkov radiation produced by the mechanism of the drive -- hence no fuel is required for in-system travel, and the ships exhibit non-Newtonian flight characteristics.

When local spacetime is flat enough, e.g. when the ship is far enough away from a sufficiently large gravitational field and/or another broomstick drive (both of which distort spacetime), a broomstick can achieve speeds greater than C, but still too low for practical interstellar flight: this is the Torus jumpdrive.

Do you mean something in the line of the Alcubierre drive?

nice. i was thinking of something more like a scramjet using the small particulate dust matter you always see floating by as reaction mass, than the alcubierre drive. although that would explain the insystem normal drive and jump drive, it wouldn't cover the witchdrive.

nijineko wrote:

is it possible to graft those abilities on in an oxp-say one type of ship only?

No.

nijineko wrote:

or would that entail core changes?

Yes.

Cmdr. Maegil wrote:

Do you mean something in the line of the Alcubierre drive?

<waves hands vaguely>That kind of thing, yes... Something that lets you guddle about with the fabric of the universe.

I thought some more about this (possibly I have too much time on my hands) and have a more pleasing solution/excuse as to why you can pitch and roll but not swing from side to side. It's because of the physical shape of the witchdrive, which looks like this from above:

<front> ------O-----##

and this from the side:

<front> ------=-----##

(I'd spend more time on the drawings but I'm at work ).

Note the big doughnut -- or torus -- in the middle, sitting horizontally. This is a quirium flywheel, which does most of the fancy spacetime-bending. It's this which prevents ships from swinging from side to side. If the witchdrive was mounted so that the torus sat vertically, not horizontally, then the ship would swing from side to side and roll around the central axis, but not pitch up and down: the inertial forces generated in subspace by the rapidly spinning quirium run perpendicular to realspace (the actual forces generated, of course, are minute: the rest of the witchdrive serves to amplify them to practical levels).

The yaw controls introduced from 1.68 manage to finagle this limitation by (very) gently twisting the broomstick, allowing a ship to dip left and right. This, as you might imagine, puts enormous strain on the drive mountings, and has only been made possible through recent developments in ultragel bearings and the subspace gimbal joint. Most ships don't yet have them fitted, and many pilots still regard such manouevres as deeply unnatural.

My word this thread got interesting.

I've worked out why my docking was (and sometimes still is) so bad. It's actually counter-intuitive in that docking at slow speeds is really dangerous. If I go in at a dead crawl, all the correcting measures seem to send me off in the strangest of angles rather than where I want them to. Matching the speed of rotation is bloody hard with keys, hammering away with small taps hoping it matches. Nope, always goes wrong.

But if I just perch a bit outside, get myself lined up, then lean on the accelerator and rush the docking port before it can all go wrong ... yeah, that works. Bit scary, but it will do until I can afford docking computers on my new ship.

The OXPs help as well. I was at Zaonce (I think), and I had some very tasty trading going in-system by ferrying stuff between the Ho0py Casino, a Space Dredger, and the PI-42 store. Got gemstones from the dredger which sold well at the casino, where I picked up furs to sell at the space station etc. Bought some fuel scoops and started looking for victims in the next system. (It wasn't piracy, just a "differently legal" way of acquiring goods to sell.) Of course, I picked on some bugger that was toting missiles and I learned not to start a fight with a trader until AFTER installing an ECM system.

I'd like to go on record and state that the yaw thrusters addition was truly helpful in all docking encounters so far, and has made the difference between dying lots, and dying less. Cheers.

I always though a Broomstick drive was, like, a Nimbus 3000......

...I'll get me cloak

Captain Hesperus

Stuff completely unrelated to yaw thrusters moved over here.

Ahruman wrote:

Lateral thrusters are very definitely not happening, because they would require us to abandon all semblance of the original Elite flight model.

Which is exactly what I did in one of my unpublished experiments - I replaced the player's ship flight model with a newtonian one using the ODE physics library.

It did make docking a hell of a lot easier, as long as you kept a tight rein on your velocity. But it didn't feel much like Elite. I even sort of regret putting in the yaw code because as soon as you use it, it feels different from Elite.

I agree with the sentiment that the Elite flight model makes no sense - all that time in the future and we've lost lateral thrusters and all, but hey, that's the game we're recreating here.

I’m not yet committed to including yaw thrusters in the next stable release. They’re experimental. I’m planning to put up a poll in this at a future point.

Maybe I’ll work on a real space sim game one day (with sufficient emphasis on the game part, as well as the sim part). But I’m not going to turn Oolite into that.

Oh, and: hi, dajt. :-)

dajt wrote:

Which is exactly what I did in one of my unpublished experiments - I replaced the player's ship flight model with a newtonian one using the ODE physics library.

OMFG!!! You did that?! Can I have it?! Can you make it an OXP???

(Yes, I know, I'm admitedly a newtonian physics junkie...)

Cmdr. Maegil wrote:

Can you make it an OXP??

No, dammit, you can’t do that sort of thing in an OXP. Even if you have magic programming powers. We’ve covered this already upthread…

Ahruman wrote:

I’m not yet committed to including yaw thrusters in the next stable release. They’re experimental. I’m planning to put up a poll in this at a future point.

Why a poll? Just put them up for sale on the shipyards as a new invention by some brilliant (and expensive) feat of engeneering - If someone doesn't like the idea, all they have to do is ignore it.

I think Big A is right, it would be almost sacrilege, Oolite is fundamentally Elite.

TGHC wrote:

it would be almost sacrilege

Luckily I'm an atheist so I don't have that kind of quelms.