Hyperspace

[robn]

Just quick notes, not in response to any particular post (I'm catching up after returning from holiday)

* The current entry point is (<radius of primary star in AU>+1) * ~11AU. Or roughly, the larger the primary star, the further out you'll be. It doesn't care at all about any other bodies, and can theoretically place you inside one. The concept is right, but it probably needs some work.

* We've discussed the mechanics of hyperspace a lot in the last couple of years, so this isn't quite new ground. I don't think we've ever really had consensus (mostly because of lack of working code to try things out).

* The idea of gravity wells limiting range has come up a few times. It seems like a nice explanation of why you can't jump all the way to near a planet, though it would mean requiring you to travel away from a body before jumping. That might be a good thing though - it would cause more interaction around starports as you might have to run away from an attacker before jumping, for example.

* We've talked about in-system jumps as well. The gravity well idea kind of works here too, if only short jumps were possible. The one thing we get stuck on is that it should never be too easy to get to where you want to be, otherwise you lose the possibilities for interaction with other ships. We haven't really been able to find the right balance here (though as noted, we haven't really tried much code).

* The idea of jumping being based on Lagrange points is an interesting one that I hadn't considered before.

Relatedly, I just read Ian Douglas' Star Carrier series while I was away. The FTL drives in those books work much like this gravity well thing- the drive only works safely in a "flat" spacetime. The ships will typically fly out to 40AU before they jump, and usually arraive in the Kuiper Belt of a system.

(Actually there's a lot of good ideas in those books. I'm quite sure they're not the first place they've come up, but still.)

[jmf]

Hyperspace is sometimes a bit too easy when the police is behind you.
When you realize that the police is too strong, just hyperjump until the alarm status is taken back.
Even with the gravity limitation - the police is also in space station far away from gravity.
Maybe a warmup phase would be useful that depends on weight of the ship and the type of the drive.

[Zordey]

I liked the frontier explanation that hyperdrives were locked out from use from within the atmosphere of a planet due to detrimental environmental issues. This could easily be triggered when the altitude gauge disappears i suppose?

A book I read a while ago (and never finished now i come to think of it) had some general explanations of hyperdrives that I thought were quite relevant, from memory:

• The further away the target system is the more accurate (and therefore more difficult) the calculations are required to get a correct exit point. ie the longer it takes to calculate correct direction and exit coordinates.
• It is almost impossible to calculate an exit point close to a gravity well because the calculations get so complex, there are too many unknown variables to take into account. Jumping into the correct system and away from planets / stars is generally all that can be calculated.
• The further the target system was away the more power was required and thus it took longer for the hyperdrive capacitors to charge. (This probably ties in with the amount of fuel used to complete the jump). In the book it took several minutes to charge the hyperdrive capacitors but this probably would not be good for gameplay in Pioneer. Maybe only a couple of seconds per lightyear traveled or something?

To limit the use of hyperdrive if attacked by pirates / police could be that you cannot maneuver the ship while it is calculating the jump solution. This would mean you would have to trade off jumping to safety with being "a sitting duck" for a period of time. One of the "X" games had a system similar to this.

[NeuralKernel]

Actually a charging mechanism might serve the purpose quite well. When you are docked you could buy a charge... when flying aroun you could build a charge with hydrogen (or military fuel) and maybe in an emergency you could charge by flying close to a star...

[Tichy]

Just to add some spice... And if we reuse the Elite idea of witch/hyperspace beacons?
The systems with a richer economy could place a beacon to be used as exit point for all the ships jumping in the system.
The volume of space could be patroled by police. There could be a space station in there, to be used as custom, or some kind of outpost. In that way, we will also force some intercation between player and npc. It will be a new kind of place to be used for missions.

For every other system, the exit point could be more random or follow some safe phisical rules.

[bszlrd]

Specified L-points could work as a beacon. The advantage of it is that there are certain orbits near to L-points where a station could be placed. And if they are far enough from the inner planets then there's a way to get the player traveling. Especially if you have to fly very far from the sun if you want to jump without an L-point, but you could use larger body's (Jupiter-Sun for example) L-point for interstellar travel and the minor L-points are usable only in-system. Like if the ratio of the Body-Parent body mass dictates ranges and costs.

This is still only about gravity and mass, and not any artificial beacon that needs power and such.

I kinda like the idea about buying charge at a station, or charging yourself with hydrogen. If the charge time is long enough then the player will consider buying it instead. And saves cargo space at the same time. And maybe it could lose charge with time, so you can't keep it indefinitely. And if you misjump without fuel this way, you might get screwed heavily.

[jmf]

Men-made hyperspace beacons would be cool.
Finally a proper use for a navigation buoys.
I think a buoy that can send its position over thousands of AU must be very expensive.
Maybe only systems with more than 5 or equal high numbers of starports can have one.
Of course there can be exceptations like Barnard's star being a very important prison system for sol.
Those buoys could also be matter of missions - Destroy one in an independant system and it will ask sol for help -> sol can invade (see expansion policy in wiki "story").

[lwho]

FYI: In https://github.com/pioneerspacesim/pioneer/pull/2399 I implemented limitations, where you can initiate hyperjumps, since I was annoyed that trade ships were jumping directly over the starting pod:

• Ship must not be within an atmosphere.
• Ship must be more than 15km above surface of a planet.
• Ship must be more than 15km away from a spacestation.

(and the non-location dependent conditions that the ship must be FLYING and have its wheels retracted).

The most complex part was providing an AIHyperspaceTo function, so that AI ships could obey the restrictions (the command flies to the closest safe place and jumps there). It will also be exposed to the player if he has an autopilot equipped.

With that in place, it should be easy to experiment with other conditions. The above rules are encapsulated in a single method Ship::GetHyperspaceSafetyDistance.

However, I think more complex rules must be presented to the player in a decent way in the GUI. Otherwise, we would have a hard time explaining users why they could not jump and how to determine where they could jump. That's why I sticked to the straight-forward rules above.

[zeonicore]

What if the police, planets, and space stations have hyperspace jammers? It could even show up on the player's GUI that their hyperspace is "jammed" in some way or another so that they know they cannot take off.