Feedback Required Your Opinion - Planetary Gravitational Fields ?

Discussion in 'General Discussion' started by Hummel-o-War, Sep 9, 2019.

?

Have gravity fields around planets?

  1. Yes

    78.4%
  2. No

    21.6%
  1. Hummel-o-War

    Hummel-o-War Administrator
    Staff Member Community Manager

    • Developer
    Joined:
    Jun 15, 2015
    Messages:
    9,899
    Likes Received:
    14,695
    As a follow up on our thread about which additions would make them more lively (https://empyriononline.com/threads/...e-the-game-world-more-vivid-and-lively.51208/) there is a very specific topic that is discussed once and a while:

    In the early versions of Empyrion, you could not park your Vessel close to a planet with engines off - as the planet would drag it into the atmosphere due to its gravitational pull. If a gravitational pull is strong enought, it might lead to not being able to get away as well (although the setting of this mechanic never was THAT strong back then) On the other hand, you could basically reach a planet if you managed to get close enough for its gravitational field to drag you in.

    What do you think - should this be part of the game again or better not?


    Disclaimer: This thread and the poll are created to get your opinion about a specific topic. It might or might not lead to being discussed further, independent from the results of the poll or how the thread goes.
     
    #1
  2. SacredGlade

    SacredGlade Captain

    Joined:
    Oct 18, 2016
    Messages:
    298
    Likes Received:
    352
    It becomes another, small consideration for players, a little step back towards "survival" and gameplay difficulty.

    Would would get better still, would be to make this a config per planet moon. So there could be variations that players encounter.

    Perhaps 3 variables:

    Strength of gravitational effect
    Distance extending from planet/moon
    Rate of reduction of field strength as you move away from planet/moon.

    The last one provides for a lessening effect as you travel away from planet.
     
    #2
  3. jlego

    jlego Captain

    Joined:
    Oct 18, 2016
    Messages:
    286
    Likes Received:
    397
    I'd be in favour of adding something close to proper gravity. Right now it's strange suddenly going from 0g to full gravity as soon as you enter a planet playfield. I only started playing in alpha 1.0, which is after it was removed, so I'm not sure what it was like, but I'm guessing that it was a fairly simple implementation.

    I'd prefer gravity according to the inverse-square law. It's easy to calculate, and it has the benefit of being physically correct. A cutoff could be added so that gravitational force below a certain level is effectively 0g to prevent drifting slowly towards the planet, and the gravity used in the calculation can be tuned for larger planets to prevent being unable to escape if this is an issue (and I'm not even certain it would be, it'd fall off fairly quickly).
     
    #3
    Combat Wombat, SacredGlade and elmo like this.
  4. SacredGlade

    SacredGlade Captain

    Joined:
    Oct 18, 2016
    Messages:
    298
    Likes Received:
    352
    A system mechanism like this could also be used to create a black hole or deep space gravity trap/feature. Which could be interesting....
     
    #4
  5. geostar1024

    geostar1024 Rear Admiral

    Joined:
    Jan 24, 2016
    Messages:
    6,145
    Likes Received:
    8,677
    Yes, but *only* with some kind of orbital mechanics as well. Gravitational wells that just pull in objects while ignoring orbital angular momentum are nonphysical and really just annoying. Unlike what you see in the movies, stuff doesn't just fall out of orbit quickly at all (even Interstellar gets this wrong during the spinning docking sequence).

    At the very least, we'd need some kind of stable orbit, which could be a simple as saying that objects are by default in circular orbits with tangential speed inversely proportional to distance from the planet. But, this would require the ability to walk around on moving ships, as ships in different orbits would obviously be moving at different speeds even when powered down.

    Basically, don't just turn on some kind of gravitational force and expect to get good results. And, as a physicist, please don't keep spreading the misinformation that gravitating bodies just inexorably pull in objects. It'd be much better to keep space playfields gravity-free than to implement gravity poorly.
     
    #5
  6. geostar1024

    geostar1024 Rear Admiral

    Joined:
    Jan 24, 2016
    Messages:
    6,145
    Likes Received:
    8,677
    Also, consider how you'd interact with a ship that had started drifting. You can't simply land on the ship and walk around to make repairs and turn the power back on (since we don't have code for walking on moving ships). You might be able to match speeds with the ship via jetpack if the drift speed were constant and not higher than the jetpack is capable of (~10 m/s), and then access the control panel to refuel a ship that had simply run out of fuel. But if the drift speed varies with distance to the planet, you'll never have time to get the control panel open before the ship has drifted out of range (and you'd be similarly out of luck around planets with a high enough drift speed). Basically, once a ship starts drifting, you have no possibility of recovering it right now, and that's not fun gameplay. And if you always keep your ship's thrusters online to keep from drifting, then you won't notice anything interesting at all (besides a continual drain on your fuel, even though you're "in orbit").

    In light of this reasoning, I'm edging toward changing my vote to "No", as I don't think Empyrion is anywhere close to being ready for this kind of mechanic.
     
    #6
    mark-o-solo, Vermillion and jlego like this.
  7. jlego

    jlego Captain

    Joined:
    Oct 18, 2016
    Messages:
    286
    Likes Received:
    397
    I agree with everything you just said. I think there needs to be a fairly big overhaul of the physics in the game, because right now vessel physics isn't exactly realistic. That said, I've yet to see the new flight model that's coming in alpha 11 (I hope), and that might be the start of it.
     
    #7
    daddychillin likes this.
  8. jlego

    jlego Captain

    Joined:
    Oct 18, 2016
    Messages:
    286
    Likes Received:
    397
    (Only saw this after I posted my earlier reply.)

    I can see why you'd change it to No, but I don't think we need to treat the question as meaning it should be implemented within the next few versions. I still say Yes, because it's something I'd like to see in the game, even if it's not any time soon.
     
    #8
    geostar1024 likes this.
  9. SacredGlade

    SacredGlade Captain

    Joined:
    Oct 18, 2016
    Messages:
    298
    Likes Received:
    352
    Great points, especially the potential downside of being on a cv, say picking growplots, when the ship us caught by gravity, pulling the vessel sideways. You would probably pass through the walls and be drifting in space....

    Not something that had considered in my earlier posts
     
    #9
    geostar1024 likes this.
  10. Watcher330

    Watcher330 Commander

    Joined:
    Feb 2, 2017
    Messages:
    94
    Likes Received:
    100
    I am completely for the addition of gravitational field (this and more realistic).

    But what happens if the ship is attracted by gravity and we are not sitting on a cockpit ?

    does that mean we can move in moving ships ? (in near futur update ?)
     
    #10
    EightyEighty likes this.
  11. geostar1024

    geostar1024 Rear Admiral

    Joined:
    Jan 24, 2016
    Messages:
    6,145
    Likes Received:
    8,677
    At the risk of getting off-topic a little, I'd argue that the underlying physics is pretty good, all things considered. We essentially have "speed-limited Newtonian mechanics with point masses, simplified moment of inertia, and constant friction in atmosphere". The big issues crop up where the devs try to get in the way of the physics (variable max speed depending on ship core rather than ship configuration) or just don't implement things correctly (CV rotation rates 10x higher than they should be just from the numbers). I doubt we'll see re-coupling of thrust and rotation, but computing the moment of inertia correctly would be easy enough.

    The big things that are missing are aerodynamics and orbital mechanics, both of which can be expensive in terms of calculations if a too-complex model is used (though they become trivial and possibly detrimental if a too-simple model is used).

    True, fair enough. I was just nervous about the devs deciding that there's an easy straightforward way to get a minimal working version of this, and there just isn't.

    Yeah, that's basically the issue I raised in my second post above. I'd argue that moving in moving ships would be a prerequisite for gravitational fields in space.
     
    #11
    cmguardia and jlego like this.
  12. mark-o-solo

    mark-o-solo Ensign

    Joined:
    Aug 16, 2019
    Messages:
    14
    Likes Received:
    7
    As a physicist and gamer, I must agree with my colleague:
    Physics should not be implemented poorly. Gravity will require pseudo forces to make stable orbits possible and that in turn would require a complete physics overhaul in empyrion. For example, one would need some 40.000 km/h for a stable orbit around a 1g planet.
    Now I personally would very much enjoy realistic KSP like physics but that's a thick extra layer of complexity, particularly when it comes to docking, fuel consumption, collisions, etc. The entailing necessity to learn orbital mechanics might scare off some players.
     
    #12
    geostar1024 and jlego like this.
  13. cpontin

    cpontin Commander

    Joined:
    May 30, 2019
    Messages:
    140
    Likes Received:
    182
    I voted yes and I agree with what has been said above about it needing to work in conjunction with other mechanics, not just be “turned on” as things are now.

    It would be good if it aligned with the gravity setting of the planet so there is a consistent (varying) pull as you enter or exit orbit and atmosphere.

    If gravity acts equally on both vessels and players then any “pull” would act almost equally in both so run-away ships may not be so much of an issue.
    I think it’s quite clear that if you hop out of your vessels cockpit and watch it get pulled away from you, this won’t be much fun.

    What would Eleon envisage the solution is to orbital bases?
    If they lose power would their position above the planet degrade?
    Would you implement some kind of orbital mechanics as part of this solution?

    Lots to think about in this discussion it seems.
     
    #13
    cmguardia likes this.
  14. stanley bourdon

    stanley bourdon Captain

    Joined:
    Oct 7, 2018
    Messages:
    386
    Likes Received:
    307
    how will this improve gameplay?
     
    #14
  15. cpontin

    cpontin Commander

    Joined:
    May 30, 2019
    Messages:
    140
    Likes Received:
    182
    One of the most interesting moments for me so far in EGS was getting stuck on a 4g lava world without a ship capable of breaking orbit.

    Adding this element to planetary orbit has the potential to enrich gameplay. It would require greater knowledge and planning when exploring the star system(s) and the creation or modification vehicles to deal with such situations. A challenge I have enjoyed immensely for high g planet exploration.

    It’s of course easy to see how some would dislike either scenario and so this needs careful consideration and lots of discussion.

    There is not currently an option to turn off gravity for planets so I suspect one won’t be offered for orbit, although you can set gravity strength in custom scenarios so there is always that option.

    One thing I would like to see added is equipment for presenting gravity warnings on the hud so we don’t accidentally end up in high g unprepared if we build accordingly.
     
    #15
    Jacob Adjani and Germanicus like this.
  16. geostar1024

    geostar1024 Rear Admiral

    Joined:
    Jan 24, 2016
    Messages:
    6,145
    Likes Received:
    8,677
    The essential problem is that Empyrion only really has one reference frame (the playfield), and thus doesn't properly handle the case where a player is moving relative to a moving ship.

    I agree that this is an essential feature (that should have been implemented along with cargo mass/volume).
     
    #16
  17. Germanicus

    Germanicus Rear Admiral

    Joined:
    Jan 22, 2018
    Messages:
    3,018
    Likes Received:
    5,840

    I agree with that.

    But this ->

    One thing I would like to see added is equipment for presenting gravity warnings on the hud so we don’t accidentally end up in high g unprepared if we build accordingly

    is already in the Game - if you read the Star field/Planetary description you get those "warnings".(if its that what you are looking for;))
    But if something is added to the Star Field that does not show up on the map which works like an "invisible" Gravity well such as a tiny black hole..:eek:
     
    #17
  18. geostar1024

    geostar1024 Rear Admiral

    Joined:
    Jan 24, 2016
    Messages:
    6,145
    Likes Received:
    8,677
    In principle, you could do something "simple" like constantly enforcing circular orbits, with orbital changes accomplished simply by moving in a Cartesian manner (radial = change orbits, tangential = speed up or slow down in an orbit without changing radius). Docking you could handle by introducing a short-range "strong force" that would act to pull objects together that started out close enough together.

    Essentially, you'd be ignoring most of orbital mechanics (and breaking conservation of angular momentum in particular), and maybe encouraging overly-simplistic ways about thinking about orbital mechanics, but you would get a mostly self-consistent semblance of orbits without having to deal with all the machinery of orbital mechanics.

    As far as I remember, it doesn't tell you how your ship's performance compares to the planet you're approaching; you still have to manually compute whether your current acceleration values would let you safely fly on the planet.

    EDIT: Regarding my simplified orbital mechanics proposal, I neglected to mention that reversing orbital direction would be done by burning tangentially to flip the tangential velocity vector, while plane changes would be done by burning normal as usual (though due to the enforcement of circular orbits, a 90-degree plane change could be accomplished purely by burning normally).
     
    #18
    Last edited: Sep 9, 2019
    mark-o-solo and Germanicus like this.
  19. Germanicus

    Germanicus Rear Admiral

    Joined:
    Jan 22, 2018
    Messages:
    3,018
    Likes Received:
    5,840
    Time for founding the EMPYRION STAR ACADEMY:D

    btw., I am no physic but for what Planet size is this number of 40.000km/h? We have as largest Planet Size 5 which is smaller than the 1st Death Star(if not mistaken) and therefore a mere fraction of Earth.
     
    #19
    mark-o-solo likes this.
  20. Kaeser

    Kaeser Rear Admiral

    Joined:
    Aug 17, 2015
    Messages:
    2,514
    Likes Received:
    4,090

    I voted yes but remembering the issue with it's first iteration, I recall players parking the ship to get out near the planet and watching the ship plummet to the planet only to get stuck in between without ever transitioning to the planet playfield and literally get stuck out of the players reach because the transitioning point was somewhere prior to where the ship ended

    This has to be corrected before we have gravity pull implemented
     
    #20
    Last edited: Sep 10, 2019
    Sephrajin and geostar1024 like this.

Share This Page