Firsly i just want to say sorry this gets a bit (EDIT: A LOT) long (and possibly rambling - but bear with it :P), but i didn't want to skip on the explanation of these ideas, as they could have such far-reaching applications in the game! There is a neat summary at the end that just states the changes (really short) but the explanation is in the main text.

EDIT: there's been a fair amount more discussion gone on in the thread and i've made a few minor changes, so please read through the thread and see how far we've got...

There have been numerous cries over even just the time i have been here (since release :P) by many different players for the ability to fly down to planets and land on them. These have mostly been said to be impractical due to the nature of the game engine and the fact that it was not designed to enable you to walk/drive around on planets and so on, and also because thats not what the game is about - i agree completely here.

However, the other day I and some others were disussing on 100 the feasability of including atmospheric flight. I am not talking about the actual flying down and landing on planets, but the creation of more varied sectors by designating some of them to be 'atmospheric' (eg some stations currently over planets could be). If you're wondering what an atmospheric zone/station would be like, think along the lines of Bespin cloud city from Star Wars. A 'mining' station in the upper atmosphere of a gas giant would be a very good example.
Basically it would be just another different environment to fly in, and the coding for it would also introduce a number of new gameplay elements if properly applied in the normal space sectors as well.

In discussing this idea we were trying to figure out how it could be done with the game's current physics engine, and (sadly without any true knowledge of that engine) we came to the conclusion that it sounded quite possible!

So heres some of the stuff we came up with. We of course were working out these ideas a bit at a time, rather than in the big chunk of stuff I present here :P

As far as i can understand the current game engine enables you to create forces and apply them to the game world directly - as seen in the fact that ships use thrust and mass to work out acceleration and also the forces exerted by concussion mines etc.
If this is true then i believe that applying atmospheric conditions would not be particularly hard. The beauty of the system is that (hopefully) if all the forces affecting a ship in an atmosphere are programmed in right then the mechanics will sort themselves out, and make the ship fly like we think it should in an atmosphere.

Here is how i think you could do this:

Each sector (including all the current space ones) is given three key attributes:

Gravitational field strength:
This represents whether there are any large (eg planet sized) objects in the area exerting a gravitational pull. A force would be created that is equal to this value x the ships mass, and would be a uniform force across the sector in an arbitrary direction that affects everything in the sector. This will only really occur in atmospheric sectors as the ones near planets in space can be said to be in orbit.

Atmospheric density:
Pretty self explanitory, a space sector would have 0 (although you could have nebulae sectors!) and atmospheric sectors could have varying values depending on the planet. This affects things like drag and lift forces on ships and how much aerodynamics (more on that later) comes into play.

Ambient temperature:
The sector itself is given an average temperature. In space this would probably be something like 10k (same as roids), and would again vary according to the planet

This particular attribute (even on its own) could add an interesting gameplay feature to the overall game though:
In sectors near stars, for example, you could make the ambient temperature very high - ships reaching a certain temperature (they would gain and lose heat according to a heat capacity which is a ship attribute) would start to take a few damage per second for every degree over a certain critical value. This could mean it is very difficult for some ships to mine (for example) in the rich metal deposits near stars, as they are not sufficiently heat shielded. Mining variant ships could come with higher specific heat capacities (gain heat slower) and critical temperatures to allow extended mining in these areas - this would be a good way to distinguish mining ships from, for example, cargo haulers.

All ships themselves would also be given a few attributes which would affect their handling in atmospheric zones:

Lift coefficients:
This is what will offset the pull of gravity in an atmosphere (although ships still have their thrusters too).

When flying along ships will generate an 'upward' (relative to the ship, not to the sector) force that is determined by the velocity of the ship multiplied by the coefficient of lift. Therefore ships like the vult and cent which have well defined wings would be well suited for atmospheric flight as they would have good coefficients of lift, and therefore would not have to thrust to fight the force of gravity when they were moving forwards.
I would recommend that ships be given a value of the coefficient of lift for not only forward (though that would be the best value) but also side to side and backwards motion, as some ships (the valk comes to mind) have a sort of 'flying saucer' thing going on and would be able to do things such as flying backwards and strafing more easily than some other ships, though they may well have less forward lift as well when compared to the vult etc...
In the ship stats it would display 'C. of lift: fwds/strafe/back'

Coefficients of drag:
These represent the actual aerodynamics of the ship and how much resistance it is likely to encounter from an atmosphere.
When a ship moves through an atmosphere it encounters a resisting force proportional to its speed - this force varies with atmospheric density and the coefficient of drag. It is important to note that ships like the vult that have good lift coefficients will probably have a slightly higher drag than you would expect, as they are turning their forward movement into an upward force and this process therefore acts to slow them down. However ships like this are also likely to be quite aerodynamic so they would still have better (lower) drag coefficients than for example the prom and atlas, which are pretty much bricks.

The equation would be something along the lines of

Drag = velocity x at. density x coeff. of drag

There would be a separate value of this coefficient for each direction (strafe up/down, left/right, forwards/backwards and spin) as many ships (vult particularly) would be vary aerodynamic forwards up because of control surfaces would be less likely to slip sideways (this is a good thing for them) than a ship like, for example, the atlas or the prom.
The presence of true control surfaces on the ship (ailerons etc) could be represented by lowering the spin drag coefficient to allow faster turning.
One interesting feature of this system is that each ship will find its own terminal velocity when drag force = thrust.

Heat capacity:
This attribute would affect how fast ships gain or lose heat when they are at a different temperature to the atmosphere or the surface of the ship. This is very important, because as a ship goes through the atmosphere at speed, the friction from air resistance tends to cause the surface temperature to heat up. This combined with the ambient temperature assigned to that area means that ships have to be very careful where they turbo!

The heat increase due to air resistance would be equal to:

temp increase / sec = (drag force x speed)/(mass x heat capacity)

I think I worked that out right (the units check out okay) - though it is simplified like the rest of these equations - they don't need to be exactly true to life as long as they work in game.

The temp increase due to the ambient temperature:

increase/sec = (ambient temp - ship temp)/(mass x heat capacity)

These too rates of increase would be added together to get the total increase (or decrease as the case may be) of ship temperature, which would be a constantly changing value as you flew through different areas. For example, you could fly into an atmosphere after being in deep space for ages and your initial temperature (which had sunk to 10K) suddenly starts to increase to the ambient temperature. After flying around for a bit you boost, which increases your temperature even more due to air resistance. Starting to near your critical temperature (at which you start to take heat damage) you decide to dive back into a space sector to cool off again. You arrive there and the ambient temp is once again 10K, and your ship begins to cool down, rapidly at first and then gradually getting back to 10k, just like in real life.

Heres one application of having temperature variations in game:
energy weapons. What about if firing energy weapons creates heat which must be dissipated by your ship (or you start reaching critical temps). The great thing about this is that larger ships would take longer to heat up and so would be able to sustain longer bursts of fire - its another alternative to trying to balance with multiple batteries and such, or could work alongside it. And the great thing is it hardly requires (as far s i can tell) much extra coding if the temperature variation code is already in; just have 'add +X temperature' added into the weapons firing scripts, and then tweak ship stats and stuff to balance. Gives the devs another weapon to work with in the balance war, and gives everyone else a cool feature and a new thing to take into consideration.

Back to atmospheric flight.

The upshot of all of these (actually surprisingly few changes - but long explanations) additions would be a whole new type of gameplay and a whole new scenario to fight in, not to mention the possibilies of gas mining and killing gas miner bots.

Ship purchasers would have to bear in mind what role they want their ship to play when they are buying. Do they want to run cargo to any atmospheric stations? Then maybe the atlas won't cut it, with its brick-like aerodynamics.

Fighting in atmospheres suddenly is a whole new ball game. Although the ships have thrusters and so on, the application of gravity and lift and drag to the combat means that position will be much more important than it is in space - getting the 'high ground' will enable you to swoop down on your opponent at high speed while they must climb up to meet you.

Some ships will not be able to go into atmospheres at all - especially loaded cargo haulers, who do not have the upward thrust to make up for their lack of lift and huge mass.

Also different ships will excel in the atmosphere. the vult and cent i imagine would fly quite like proper aircraft, focussing on forward speed and making strafing runs, with the option of using thrusters to perform tight maneuvers and for docking. Contrasted to this, the prom and valk would probably still fly more like space ships (moving in all directions and so on) but would still be restricted by the fact that they can't reallymove that well as they have to use their thrusters to counteract gravity.

And then of course there is the possibility of having specialised atmospheric craft. These would be exactly like normal ships, just with imporved stats in terms of lift coefficients and reduced forward drag, but they would not have particularly good thrust in itself for example. So while they may be faster and more maneuverable than the space ships in atmosphere, their low thrust would show through in space where aerodynamics do not restrict the other ships.

As you can see there are many possiblities of having a system like this in the game, and i believe it would diversify the different roles to be played and make the game more interesting to play as a whole.

And just to show you that all that blab up there was mostly by way of an explanation and that the actual changes are quite simple, here are the actual game changes summarised:

Each sector now has
a) a gravitational field strength value (space 0)
b) an atmospheric density value (space 0)
c) an ambient temperature (space about 10K)

Ships now have:
d) coefficient of lift (forward/sideways/backward)
e) coefficient of drag (forwards-back/left-right/up-down/spin)
f) heat capacity
g) current temperature (stations reset to a certain value)

Once you have this stuff in, you have to put in

Gravitational force = mass of ship x (a)
In an arbitrary direction across the whole sector

Lift force = (d) x ship speed x (b)
In an 'upward' direction RELATIVE TO THE SHIP.

Drag force (or torque) = (e) x ship speed x (b)
In the opposite direction to the movement of the ship (or the rotation direction, for spin drag), whether the ship is moving forward or strafing or rotating or a combination.

Temp change/sec (friction) = (drag force x velocity)/(mass x (f))

Temp change/sec (due to ambient temp) = ((c) - (g))/(mass x (f))

Temp change/sec (total) = change due to friction + change due to ambient temperature

Current temp changes constantly according to this value - it starts at a preset value in stations and stations reset to that value.

And there you have it! And it fit in one page-length even with all those spaces! :P
As far as i can figure, thats all the changes you'd need to make to have atmospheric flight, temperature variations, the possibility of weapon heat, gas mining and the different gameplay styles that would follow. Tweaking a few values would enable high temperature mining ships, atmospheric fighters, nebula sectors (have atmosphere but no gravity) and a bunch of other cool stuff too!

Sorry this has been such a long post, but having this idea was like pulling a thread out of a jumper - it just kept going and giving me more ideas! :P

Feel free to comment/criticise (contructively) on anything here, correct equations and mistakes and so on, and add to the list of 'cool stuff' that we could do with this!

Thanks for reading :)

How would one use a warp engine in an atmosphere? you'd be awfully close to a planet...

well you'd have to get a certain distance 'up' i suppose - that'd be the easy way to implement it.

All they have to do is add a 'large object' all across one side of the sector, and give that edge a groundlike texture (or clouds, whatever)

Then you'd have to fly more than 3000m up away from that large object - same as usual

EDIT: also im not sure i stressed enough: the coefficient of drag for sideways and up/down motion on something like the vult would be VERY high compared to the drag for forwards/backwards motion - this would mean it would fly like a normal aircraft, whereas on something like the valk (ie a flying saucer :P) the drag would be close to the same in all directions, which would make it fly completely differently.

Another thing: don't forget that with flight assist on, even the ships that have no lift would stay straight and level as the computer would calculate the amount of thrust needed to fight gravity - this means you wouldn't have to hold the button down. You'd have to be sure your ship could push hard enough for your load though :P

IF the devs had time to impliment a atmosphere/fog rendering engine, IF they implimented global forces (do you know how long it took for us to get rockets that "pushed" their targets), IF they reorganized the sector maps to show "planet" sectors, THEN it might be a workable idea.

well i did mean it to be pretty long term, and like i said i didn't know how limited the engine was, so i figured i might as well put it down here :)

So yeah they'd need to do the fog and stuff. Though they could cheat and make clouds which are fluffy roids with no clipping :P

Why is the global force so hard - surely they could just make it a force on every ship in the area - sorry i don't know why that is difficult but thats my ignorance showing. How long did it take for the missiles to be worked out then? and surely the difficulty was that there was a blast radius and they had to work out the effect on the ship in terms of force and direction - i would have thought that *applying* that (or any other) force would be the easy part.

And the sector maps do show planet sectors - they'd just have to put an asterisk or something next to the station name to show that its an atmospheric station.

EDITs: sorry this keeps expanding :P

And what would happen to pilots whose ships don't have enough lift/power to overcome the force of gravity?

I do like the idea of sectors having temperatures based on their proximity to the sun. All roids in the sector should start at that temperature.

The heat generation thing reminds me of Mechwarrior...
Of course in space you have to rely on radiative cooling, which is very inefficient.

once those ships reach the 'large object' hehe --> teh boom, so make sure you go in a ship that can handle it, or don't go at all.

Don't forget, its only the ships maneuvering thrusters that have a chance of being overpowered by gravity - if you get in trouble, turning upwards and boosting should do the trick :P

Yeah the weapon thing and the sun thing were just cool ideas i had that could be easily applied if this whole system gets put in place (which would be a pretty long time probably) - but once its in, just change a few variables and we get all this great new content just like that!

EDIT: just thought of something cool what if all ships leaving an atmospheric sector could only warp (for that first jump) to a specific one of the sectors next to it - to represent getting into orbit and then jumping from there.

For example: you're at serco prime (now atmospheric) and you want to go somewhere else. So you climb out until the meter reads 3000m away (from the large object that is the ground edge of the sector) by which time you have left the clouds behind (just like you can turbo out beyond roids now). You then jump, but instead of going where you select, you first jump to skycommand (which is in orbit of the planet) and THEN can go out and jump as normal.

What d'ya think? be interesting if that place happened to get an ion storm, the planet would be sort of shut off for a while - you'd have to go to the storm exit to get in or out of the atmospheric sector :)

I just remembered - they must have SOME kind of system they can use for clouds - we experience it all the time!

Ever been in an ion storm?

What about all that space debris?

The clouds wouldn't really have to move (at least not to begin with - leave that for later) as the ship would be moving anyways.

I agree that atmospheric flight would be very interesting but it should serve a purpose in the game, like protecting an installation on the planet surface against an assault from space. Gravity, combined with an atmosphere, would also be an interesting addition, although the staggering power of the current engines (they are actually kN, not N?) makes gravity a bit irrelevant. Just the atmosphere: no thanks.

I did find the idea of heat an interesting one as heat dissipation is a real life problem. Now the pilot will probably get mighty cold in 10K but e.g. the energy weapons (super conductors etc.) might just stop working if they get too warm. Large ships should have more powerful cooling systems.

Heat radiation from a star might be nice, especially if surface exposure counts and one could chill out behind an asteroid. Yet untill we get stealth ships there might be little _benefits_ from modelling heat.

Of course you'd give it a purpose, such as gas mining using the cloud-roids i mentioned before. But the main purpose of having these sectors would be to introduce some varied environments to play in - at the moment its all space, but why not sectors that are close to stars, atmospheric sectors, nebulae, normal roid fields and other cool places?

Variation is very important but yes it would also allow special missions to be written for the environment like you say.

Whats wrong with having an atmosphere? Thats what makes it interesting; if you only have the gravity, its just a nuisance.

Gravity is actually quite strong when its a planet exerting the force, something the size of even earth would put a force of about 50000N (50KN) on the average 5000Kg fighter and 300Kn on a loaded up centaur, which would strain engines if you don't have any lift. Mainly though the impact is not in the ability to travel in that sector, but on the ships ability to maneuver, especially during combat.

Of course if you want to be doing this while mining a gas giant the force is going to be much greater, but i think they can basically tweak the values however much they like because in the end good gameplay > realism (just like with max speeds on ships).

What do you mean there would be little benefit in modelling heat? You just mentioned some (star sectors and mining) and of course there is the weapons. Yes it is a *restriction* not a benefit directly to any ship, but it is one that induces some interesting gameplay.

I did not bother to read the OP. It was too long and complicated.

I like the general thrust of the idea. I know this is not my game to design, but if it -was- I'd have drastically fewer sectors and concentrate on the specialness of each sector. VO does a great job already with asteroid fields and stations. There just aren't many other interesting places to go. Most of the sectors are voids. Realistic, yes; fun, no.

So the upper atmosphere of a gas giant is a magnificent idea. Unfortunately, it is probably impossible to render something like that without everyone taking a massive framerate hit whenever the planet swings into view, which undercuts the fundamental gameplay of VO.

You probably should have read the thread :P (i know its long sorry, but there is a lot of cool stuff in there as well as explanations) - and as for framerate hits - like i was saying, they do ion storms and space debris, and i haven't noticed any framerate hits in ions...

Yes its not exactly the same thing, but its on the same principles

I think for ions and stuff they just make it so you can only see the clouds flying past on your screen (rather than them being a sector object) which would be fine for the clouds - after all visibility is the only effect they need to have.

For an atmosphere they would probably have to use GL_FOG and the DX equivalent...

lol you've lost me there - thing is im suggesting all this stuff but i have no idea what they can and can't do (which is partly why this thread is here). I'm pretty much just trying to use some common sense with what little programming knowledge i have (see: zip hehe) and trying to think around the problems

Basically i hope to get to a point in this thread where we know it is possible to say "yes, there don't seem to be any reasons left that we can't do this, and yes we'll think about it for the future"

So lets make a start:

*Can* they do an atmosphere using whatever method it is rogue is talking about? How would it work (not in *too* much detail :P)? Will it cause framerate or lag issues? If so are there any other ways it could be done?

If we can go through each issue like this and sort of tick them all off, thats going a long way to getting cool new stuff in the game! Of course a Dev comment on said issues would be great ;)

Being -inside- a foggy area is renderable on many cards with little or no performance problem. But looking at a real-time rendered gas giant when you are -not- inside it, that doesn't go so well.

Soulless: true, too much realism just spoils the fun. :) E.g. the flat planet surface is a good enough approximation with the vehicle speeds in VO. But I would miss the property of atmospheres that they grow thinner the higher you go.

Hmm, I miscalculated: the thrust of some of the vehicles is not enough to (easily) lift off in 1G but well enough to maneuver in orbit. You are right, it might be just right for a different kind of fighting. Yet the very exitement of gravity wells is not falling down them: the atmosphere must end somewhere deep down where the ship either crashes or implodes.

I don't believe nebulas are thick enough to be considered atmospheric: it takes a strong gravity to compress that gas. Maybe a planet in forming (asteroids + gas + gravity) or give ion storms that property (without gravity)?

Further on the proposal: I'd reduce the aerodynamics to just friction, how it opposes movement and causes heating. Just to keep the task more manageable at first. Oh and make friction more like F=velocity^2*coefficient*pressure. Too much friction and a ship will start to break up? The friction coefficient (or similar) could be used to represent the average surface exposure to radiation from a star.

As to the heat itself, I was just wondering if the complexity is really necessary (I loved it in Mech Warrior). Malfunctioning devices would be a new feature at least. Maybe heat activated minefields? Or heat scanners for stealth ships. Heat producement might be another way to create variety in weapons.

I wouldn't distribute heat over the whole mass: there probaly should be hull temperature (melting armour) and a counter for each attached device. Each ship would be able to dissipate a certain amount of kg*K per second (1000kgK/s: a 5 ton ship cools down one kelvin in 5 seconds). Engines should warm up the hull.

'Being -inside- a foggy area is renderable on many cards with little or no performance problem. But looking at a real-time rendered gas giant when you are -not- inside it, that doesn't go so well.'

Well it was the being inside that was what i was talking about.

Maybe i didn't describe the sectors well enough. Here you go

Imagine a sector exactly as it is now. Now fill the whole thing full of gas, and have a FEW extra thick clouds that use the code for roids (so you can mine them) but that are opaque and have no clipping so you can just fly through them with no effect. They are not 'large objects'.
At one 'end' of the sector at a determined position there would be a huge invisible flat surface that counts as a large object for warping purposes and you explode if you touch it. This would use exactly one polygon :P (one HUGE polygon but still).
They make sure you only ever warp in on the correct side of that surface.

Normal background textures much like the ones we have for the stars and planets now would be put in the background of that side of the sector, but would just be a picture of more gas and stuff - this would be huge compared to the sector and appear to be looking downwards at swirling gas clouds - all of that would be done using the current background textures. The other 'sides' of the sector would have more gas pictures, and the top panel would have stars and stuff as usual.

The gravitational force would apply to every *ship* (you could say that cargo has an AG suspensor field or something and model thrustors on the stations) in the sector and would always pull directly towards the 'large object' surface.

Then your altitude will be given pretty much by your 'distance to large object' meter other than when you're near the station, and when you're near the station well you can see how high you are :P

all you have to do to go 'back into orbit' is fly upwards at least 3000m and warp normally.

There is no point at which you are 'outside' the gas cloud.

I think thats everything...tell me if i missed anything out

wanted to do a separate reply for you margoth:

'Further on the proposal: I'd reduce the aerodynamics to just friction, how it opposes movement and causes heating. Just to keep the task more manageable at first. Oh and make friction more like F=velocity^2*coefficient*pressure. Too much friction and a ship will start to break up? The friction coefficient (or similar) could be used to represent the average surface exposure to radiation from a star.'

What do you mean reduce them to just friction? What aspect of friction do you not want in?

You mean ignore the heating effect? Yes, we could do that but i put it in cos if you put in friction it would be pretty easy to get the heat from this, and it opens up all the cool stuff about star sectors and such. As for 'the complexity' with heat as you call it, well much of that is part of the 'optional but cool' catagory; if you already have ship temperature in game, how hard is it to make the weapon firing script add +X to the temperature per shot? The only issues there are balance issues and this part of the heat system could still be rolled out separately after you've had time to tweak.

If you mean take away the drag and just leave the heating effect, then no, sorry you simply couldn't do that. Why? Because then a ship wouldn't fly like it was in an atmosphere - you need the drag or its just space with penalties for going too fast.

By the way the equation 'F = velocity^2*coefficient*DENSITY' is actually more true to real life, though the in game application would be the same whether you allocate the sector a density or pressure - you could tweak either to suit its just a number. For the same reason you don't really need to square the velocity - you just mess around with the values.

As for nebulae - there has to be some point between nebula and gas giant - i know the gas giant has a solid core but at some point it was probably just a dense nebula. So you could just say - this sector is in the middle of a dense nebula it has an atmospheric density of X.

Ships already have a cooling mechanic built into my suggestion. Have a look again - in a sector that is cooler than it a ship will cool down according to that difference. It would be pretty easy to code in a cooling system as well if you want (so like mechwarrior you buy cooling systems to go with energy weapons) - you just code that it drops your heat by X Kelvin/second per device.

As for 'engines should warm up the hull' thats something to be discussed later (ie turbo heats you up) once the temperature change system itself is in place.

EDIT: btw i don't have internet at home right now so i won't be answering questions until tomorrow, then i'll try to get through them all.

I love these long term(?) ideas..

As i am not a prgrammer i know nothin' bout that, but i can see how this hopefully doesnt require a redo of the game engine, just some tweeking and voilá..

Maybe the gas roids is an idea that can be done fairly easy, just for variation, add some new widgets/weapons/beams?

A a high temperature gasbeam would make a lot of damage to a hull, or it could have corrosive dammage, lets say some armour per sec, and you'd have to dock to fix it

That would make an already awesome game even more fun!

BTW: The engines on our ships don't put out enough force for vertical flight, or anything approaching it. Our engines put out something like a maximum acceleration of 0.04 m/s^2, compared to a earth-size gravitational acceleration of 9.8 m/s^2. To move a 10000kg ship with an acceleration of 9.8 m/s^2 (allowing a ship to "hover" vertically) would require an engine capable of a force of 98000N. Of course, I'm thinking that all the values on ships' thrust are off. Assume it takes a 10000kg ship 5 seconds to accelerate from 0 to 50 m/s. That means that it has an accleration of 10m/s^2, which means that it has a force of 100000N. Which means that we can't have engines that only output 680N (at most) of force and still have our current speeds. Hmm. Perhaps I should post this else where...