Magnetic Field

[DiamondExcavater]

just a suggestion for a realistic mode to add to career, in real life the magnetic field draws objects into itself, especially the closer it is. i think all planets with a molten core should have the magnetic field, comment below what you think!:P:)

[bartekkru99]

just a suggestion for a realistic mode to add to career, in real life the magnetic field draws objects into itself, especially the closer it is. i think all planets with a molten core should have the magnetic field, comment below what you think!:P:)

Nah magnetic field pulls only charged particle in a noticable way. It's done in Interstellar mod, where you need to collect antimatter in Van Allen belts.

[Damien_The_Unbeliever]

There's already a field that every body has in the game and draws objects in - it's called gravity.

[vexx32]

Aye, as others have said, a planet-sized magnetic field only has a noticeable effect on microscopic particles. If something like the solar wind was simulated, then it becomes a bit more plausible to start simulating magnetic fields, but simulating any of that has almost no real effect on the game whatsoever; it'd just be a very pointless feature eating up CPU cycles.

[DiamondExcavater]

the magnetic field might have a small amount of force but the closer to earth you are the stronger the pull, however there is still a deorbiting force that actually pulled down mir (a soviet space station) and is constantly pulling other stuff that's flying around up there in space. i thought the force was the magnetic field, but even so, everything in orbit will eventually fall towards the mass. even our moon, even though it may be in the perfect orbit and not too close eventually it will! this will make game play harder and also mean you need to resupply satellites and stations with fuel every now and then, how about having this kind of stuff available? http://science.nasa.gov/science-news/science-at-nasa/2000/ast09jun_1/ also en.wikipedia.org/wiki/Momentum_exchange_tether

thanks for comments BTW

[Tuareg]

the magnetic field might have a small amount of force but the closer to earth you are the stronger the pull, however there is still a deorbiting force that actually pulled down mir (a soviet space station) and is constantly pulling other stuff that's flying around up there in space. i thought the force was the magnetic field, but even so, everything in orbit will eventually fall towards the mass. even our moon, even though it may be in the perfect orbit and not too close eventually it will! this will make game play harder and also mean you need to resupply satellites and stations with fuel every now and then, how about having this kind of stuff available? http://science.nasa.gov/science-news/science-at-nasa/2000/ast09jun_1/ also en.wikipedia.org/wiki/Momentum_exchange_tether

thanks for comments BTW

oh man. squad cant even program correct gravity forces how u think something this complex? tidal force would be the most basic thing and its completely ignored

Edited February 1, 2015 by Tuareg

[KSK]

oh man. squad cant even program correct gravity forces how u think something this complex? tidal force would be the most basic thing and its completely ignored

There's a difference between 'can't program' and 'not going to program because we don't think it adds to gameplay'. But that's off-topic for this thread and something that's been discussed time and again in other threads.

Mir was de-orbited by atmospheric drag. The real life atmosphere doesn't have a nice neat cut-off as it does in KSP so, unless they're high enough, vehicles in LEO will tend to deorbit over time. Which is handy for getting rid of space debris. Magnetic drag is a thing but it's a tiny effect compared to atmospheric drag, and so ignored in most real-life calculations.

I guess you could sort of simulate atmospheric drag, the need to reboost orbital vehicles etc. in KSP right now by placing a space station so it's periapsis dips just inside the 70km atmosphere cut-off limit. It would be pretty tedious though, not least because as soon as you switch to another vehicle, the simulation would go 'on-rails' for your space station, meaning that it would no longer be affected by drag.

Tethers etc. - very cool, not going to happen in KSP because of the 2.5 km limit to the physics simulation. I'm guessing that rewriting such a basic part of the game would be quite a bit of work and probably not worth it this late in development. I know I could think of many more uses for developer time that would have a bigger impact on the game.

Edit: Slight correction, Mir was de-orbited deliberately, presumably so it could be dropped safely into a nice deep ocean rather than somebody's back yard. However, from Wikipedia: "Mir's deorbit was carried out in three stages. The first stage involved waiting for atmospheric drag to reduce the station's orbit to an average of 220 kilometres ". So atmospheric drag alone would have de-orbited it given enough time.

Edited February 2, 2015 by KSK

[Sirrobert]

the magnetic field might have a small amount of force but the closer to earth you are the stronger the pull, however there is still a deorbiting force that actually pulled down mir (a soviet space station) and is constantly pulling other stuff that's flying around up there in space. i thought the force was the magnetic field, but even so, everything in orbit will eventually fall towards the mass. even our moon, even though it may be in the perfect orbit and not too close eventually it will! this will make game play harder and also mean you need to resupply satellites and stations with fuel every now and then, how about having this kind of stuff available? http://science.nasa.gov/science-news/science-at-nasa/2000/ast09jun_1/ also en.wikipedia.org/wiki/Momentum_exchange_tether

thanks for comments BTW

Actually the moon is slowly moving AWAY from the earth.

That force slowing down things in orbit you confuse with magnetics? That's called drag. There are still air particles up there, and they still slow things down.

And constantly having to reboost your crafts so they don't fall down out of orbit doesn't make the game harder. It just makes it extremely tedious, forcing you to go throw a massive list of chores each time you timewarp a little

[Tuareg]

There's a difference between 'can't program' and 'not going to program because we don't think it adds to gameplay'.

huhhh, what a bad excuse. u say proper gravity is programmed so badly and buggy because a flawless one wouldnt add to the gameplay? I want to sell my next software to you first best ever customer

[KSK]

huhhh, what a bad excuse. u say proper gravity is programmed so badly and buggy because a flawless one wouldnt add to the gameplay? I want to sell my next software to you first best ever customer

Go ahead. Just be sure to a) charge me a minimal fee, b)make it useful or fun (depending on software type) from the outset, and c) send me a steady stream of upgrades and significant improvements for the next two years.

Back on-topic, I might not be getting what you meant by 'correct gravity forces'. As far as I can tell, gravity works just fine, albeit using a simplified model (planets-on-rails and a patched conics approximation.). As other folks have pointed out, a proper n-body physics model would be feasible and, assuming it can be implemented in Unity, I've personally got no doubts that Squad could build one if they wished. It would make the game more complicated though, and I'm not sure that the added complications would be worth it. For example: tidal forces. They would have a microscopic effect on the Kerbol system over the course of a game, so no gain there. Seeing proper tides on Kerbin would be pretty cool but (to me) would be a 'nice to have' more than anything else.

Which bugs and bad programming did you have in mind?

Edited February 4, 2015 by KSK

[RainDreamer]

I wonder if they are asking for N-body gravitational simulation. Isn't that thing really hard to get right?

[Tuareg]

Go ahead. Just be sure to a) charge me a minimal fee, b)make it useful or fun (depending on software type) from the outset, and c) send me a steady stream of upgrades and significant improvements for the next two years.

Back on-topic, I might not be getting what you meant by 'correct gravity forces'. As far as I can tell, gravity works just fine, albeit using a simplified model (planets-on-rails and a patched conics approximation.). As other folks have pointed out, a proper n-body physics model would be feasible and, assuming it can be implemented in Unity, I've personally got no doubts that Squad could build one if they wished. It would make the game more complicated though, and I'm not sure that the added complications would be worth it. For example: tidal forces. They would have a microscopic effect on the Kerbol system over the course of a game, so no gain there. Seeing proper tides on Kerbin would be pretty cool but (to me) would be a 'nice to have' more than anything else.

Which bugs and bad programming did you have in mind?

a, dont worry, it will be nearly free. b, if ksp in its current form is fun for you, it will not be difficult. I will just copy/paste a tetris. c, no problem, i will add a new color every 4 months or so...

Back on-topic, if you check out my mods, you can see I was playing a bit here and there with KSP's gravity and I can tell you, even zero gravity doesn't work, don't even mention the planets. N body physics CAN be implemented in any program, it's Squad's ability is the problem. Even bullet physics can be used in Unity. Creating the game =/= popping models into a game engine, giving them parameters and let them run... This is quite what KSP is. Funny that even the mod loading module is a mod originally. Tidal forces are the basics' of any orbitmechanism. Why do we model a fake something which isn't even close to realistic if we could make it look realistic with just one more lines? and those tiny tidal forces would mean a lot in KSP as the objects looking towards one point of the sky while on orbit is completely wrong. I don't know how is it in mexico but in hungary every kid in the primary school has at least 4 years compulsory physics studies and except the most stupid ones everybody knows how gravity works...

what is on the first image is the natural way in reality. the second image is when the object has an initial angular force and its against the relaxed orbiting. that's when tidal forces appear to relax that initial rotation. though in KSP (and in reality) you are able to stop that initial rotation with other tools (like the gyro) and after that the first, relaxed way should apply. but in KSP it doesn't, your ship will keep looking at one point of the sky. its fake, its ugly and its disappointing.

(I forgot to add, that over that its ugly and fake, it makes satellites completely pointless)

Edited February 4, 2015 by Tuareg

[RainDreamer]

There is this thing in development that attempts to simulate N-body gravity. It looks difficult. Can anyone help with its development? See how it perform, then maybe we have a proof of concept that squad can learn from?

Edited February 4, 2015 by RainDreamer

[KSK]

a, dont worry, it will be nearly free. b, if ksp in its current form is fun for you, it will not be difficult. I will just copy/paste a tetris. c, no problem, i will add a new color every 4 months or so...

Back on-topic, if you check out my mods, you can see I was playing a bit here and there with KSP's gravity and I can tell you, even zero gravity doesn't work, don't even mention the planets.

I already mentioned that those were on rails.

Why do we model a fake something which isn't even close to realistic if we could make it look realistic with just one more lines?

Because looking realistic isn't necessarily the same as being fun. Clearly it is for you, but other players may not agree.

and those tiny tidal forces would mean a lot in KSP as the objects looking towards one point of the sky while on orbit is completely wrong.

*snip*

what is on the first image is the natural way in reality. the second image is when the object has an initial angular force and its against the relaxed orbiting. that's when tidal forces appear to relax that initial rotation. though in KSP (and in reality) you are able to stop that initial rotation with other tools (like the gyro) and after that the first, relaxed way should apply. but in KSP it doesn't, your ship will keep looking at one point of the sky. its fake, its ugly and its disappointing.

I admit that I don't understand what your diagrams are showing (and so this could be completely wrong) but it sounds like you're talking about gravity gradient stabilisation (GGS). I think this could work in principle in KSP but getting it to actually work would be difficult.

Quick summary of GGS as I understand it. Newtonian physics - gravitational force follows an inverse square law with distance. Therefore different parts of a spacecraft will experience slightly different gravitational forces, giving rise to a net force on it. That net force will cause the spacecraft to orient such that its lowest moment of inertia will be about an axis pointing towards the centre of the body which the spacecraft is orbiting, i.e. along the gravity gradient.

All this falls out naturally from that initial inverse square law. I find it hard to believe that KSP isn't using that, since otherwise nothing about it's physics model makes sense. And within the patched conics approximation, KSP physics does make sense.

However, KSP also has two other features which make effects such as GGS very difficult to see in-game. Time-warping a vessel puts that vessel 'on-rails' - it follows a fixed path in a fixed attitude and external forces acting on it, such as atmospheric drag and gravity gradients are ignored. Similarly, vessels which the player aren't currently controlling are also put on-rails. I'm guessing this is done for optimization reasons, so that the player can have several spacecraft in play at the same time, without slowing the game down by subjecting all of them to the physics model. It also means that spacecraft which the player isn't currently flying will follow a completely predictable path, so that the player doesn't have to worry about them going off course. Both of which seem like entirely acceptable reasons to compromise realism in favour of gameplay.

If external forces aren't applied, then a spacecraft will maintain a fixed attitude relative to the sky, which is exactly what we see in-game for time-warping vessels. If you were patient enough, in principle I think you could set up a suitable spacecraft in orbit around Kerbin, not use any time acceleration, switch off SAS and watch as GGS pushes it into a physically correct attitude. In practice, stock KSP controls aren't precise enough. I've tried something similar myself by switching off SAS and trying to put a ship into orbital rate - but I can never set up the ship rotation accurately enough for it to work.

Edit. Agree with RIC's comment, so this is my last post here. Happy to take the discussion off-thread or onto a different thread.

Edited February 4, 2015 by KSK

[Red Iron Crown]

Why is there so much talk of gravity in a suggestion thread about magnetic fields? Start a new thread rather than cluttering this one with off-topic responses, please.

On-topic: I'd have to agree that magnetic fields are likely not worth modelling, unless some sort of radiation system is added. Those planetary magnetic fields do provide good protection, making planets with fields "safe harbors" from solar radiation. That would be kind of cool but it's not a planned feature afaik.

[Tuareg]

I already mentioned that those were on rails.

Because looking realistic isn't necessarily the same as being fun. Clearly it is for you, but other players may not agree.

I admit that I don't understand what your diagrams are showing (and so this could be completely wrong) but it sounds like you're talking about gravity gradient stabilisation (GGS). I think this could work in principle in KSP but getting it to actually work would be difficult.

Quick summary of GGS as I understand it. Newtonian physics - gravitational force follows an inverse square law with distance. Therefore different parts of a spacecraft will experience slightly different gravitational forces, giving rise to a net force on it. That net force will cause the spacecraft to orient such that its lowest moment of inertia will be about an axis pointing towards the centre of the body which the spacecraft is orbiting, i.e. along the gravity gradient.

All this falls out naturally from that initial inverse square law. I find it hard to believe that KSP isn't using that, since otherwise nothing about it's physics model makes sense. And within the patched conics approximation, KSP physics does make sense.

However, KSP also has two other features which make effects such as GGS very difficult to see in-game. Time-warping a vessel puts that vessel 'on-rails' - it follows a fixed path in a fixed attitude and external forces acting on it, such as atmospheric drag and gravity gradients are ignored. Similarly, vessels which the player aren't currently controlling are also put on-rails. I'm guessing this is done for optimization reasons, so that the player can have several spacecraft in play at the same time, without slowing the game down by subjecting all of them to the physics model. It also means that spacecraft which the player isn't currently flying will follow a completely predictable path, so that the player doesn't have to worry about them going off course. Both of which seem like entirely acceptable reasons to compromise realism in favour of gameplay.

If external forces aren't applied, then a spacecraft will maintain a fixed attitude relative to the sky, which is exactly what we see in-game for time-warping vessels. If you were patient enough, in principle I think you could set up a suitable spacecraft in orbit around Kerbin, not use any time acceleration, switch off SAS and watch as GGS pushes it into a physically correct attitude. In practice, stock KSP controls aren't precise enough. I've tried something similar myself by switching off SAS and trying to put a ship into orbital rate - but I can never set up the ship rotation accurately enough for it to work.

adwaaaaaa

Edit. Agree with RIC's comment, so this is my last post here. Happy to take the discussion off-thread or onto a different thread.

you overcomplicate it. to make it simple an orbiting object which doesnt have external forces applied has the same rotation as its orbit so it always look into the center of the orbited body. it could be freaking easily simulated both in active both in rail mode. its the natural way, its logical, its simple, its realistic and its more fun

[Red Iron Crown]

MODERATION: The gravity discussion is off topic, this thread is not about gravity. Take that discussion elsewhere, please.