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Is there a way to not have ships reach max speed easily in atmosphere?

Discussion in 'General' started by SirConnery, Mar 7, 2019.

  1. SirConnery Trainee Engineer

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    So I'm thinking if there is a way to mod in a way for ships to not achieve max speed so easily. It doesn't matter if you set max speed at 200m/s or 1000m/s achieving that speed seems to be possible with almost any ship. What I would like is to make it much harder to keep accelerating forward in atmosphere. I think the vertical acceleration is in a really good spot right now, but the horizontal acceleration speed seems to just be overkill because it doesn't slow down.

    I'm not really sure what it is that keeps real planes from not accelerating infinitely in atmosphere. Heat? Planes getting ripped from too many G-forces? Something else, maybe. Anyway, I would like to mod in a limiting factor so you would have to make specialized craft for long travelling in speed.
     
  2. Soup Toaster Apprentice Engineer

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    I'm not sure if many people would want realistic drag as standard considering so many of our creations are basically flying bricks. :) I think there might be mods out there for this though?
     
    • Agree Agree x 1
  3. SirConnery Trainee Engineer

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    I don't mean shape affecting aerodynamics. I mean doing away with infinitely accelerating forward in atmosphere.
     
    • Agree Agree x 1
  4. Sarekh Senior Engineer

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    I think @Soup Toaster does understand this - the problem with bricks ist that they're specialized - my bricks for example would just cease to function properly if they would have to account for horizontal slow-down - not that this would not keep me from happily redesigning, just sayin' :-D
     
    • Agree Agree x 1
  5. Stardriver907 Senior Engineer

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    Any ships I have that need to operate in atmosphere do so by brute force. Nothing aerodynamic about them.

    Drag is what brings real planes back to earth if they're not flying. Drag and gravity. SE has gravity, but it does not have aerodynamic drag. There is a mod that uses special blocks that behave differently according to speed and relative direction. In other words, if you go forward the block will move you upwards, and if you slow or stop you go down. For SE it works close enough to what really happens.

    I've never used the mod myself, but I have seen it used successfully. However, from time to time there have been problems. Also, I think there is more than one mod. I'm surprised no one has posted a link already.
     
    • Agree Agree x 1
  6. SirConnery Trainee Engineer

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    But drag doesn't slow you down when accelerating forward does it? That's what I would want to do. Drag is what brings down your plane vertically as far as I understand. You don't have enough airflow above your wings > stall. That's not what I'm looking for.

    I don't really even know the reason why planes in real life don't just accelerate indefinitely in atmosphere, but someone here probably knows. I don't really need a real life reason for it though. I would just like there to be a curve where you would need multiple forward engines to be able to accelerate to max speed. Now if you can accelerate 5m/s you just keep going until you hit the speed max be it 100m/s or 5000m/s.
     
  7. plaYer2k Master Engineer

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    Well call it "air resistance" then. The friction of a ship moving inside an atmosphere results in slowing it down due to the loss of energy with the collision of those particles, turbulences etc.
    As others pointed out, that simply doesnt exist in SE and likely never will in a proper way because aerodynamics are a very demanding branch and could only just be abstracted very roughly.

    There have been aerodynamic mods in the workshop and maybe you can find a nice one. I dont know which one is most up to date and offers the best features, so you gotta check that youself.

    Search for: aerodynamic, drag and deadly reentry
     
  8. SirConnery Trainee Engineer

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    (multiple editing failures)

    So, I tried to look it up and indeed it's the drag effect/air resistance that is the limiting factor on planes in atmosphere in real life.

    "In aircraft not designed to fly at or above the critical Mach number, the shock waves that form in the airflow over the wing and tailplane are sufficient to stall the wing, render the control surfaces ineffective, or lead to loss of control of the aircraft"
    https://en.wikipedia.org/wiki/Critical_Mach_number

    But for my purposes I don't really need a realistic effect. I just need some way to limit the infinite increase in forward acceleration. Is there some way to do this?

    Also to add, I already play with the Aerodynamic Physics (deadly re-entry+drag+flight) mod on my server. It does absolutely nothing to accelerating forward.
     
    Last edited: Mar 8, 2019
  9. Calaban Junior Engineer

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    I don't see a problem with it as is. Here's why:

    Take the landing pod, mount the cockpit and gyro on it, and take it for a flight. Yes, you will start accelerating whichever lateral direction you are leaning.

    This is because your basically falling over.. but the gyros add enough counter rotation to help hold the craft that certain way.. so , if you are tilted to the left, you are basically ' falling' to the left. And the gyro prevent you from falling all the way over in a rollover.

    This falling is the acceleration. And like a book on it's edge falling to the left without a gyro to benefit it, it will indeed accelerate as it falls over.

    So a flying ship, already demonstrating it's ability to output more thrust than it weighs ( by being able to lift off) can ' fall' that way effortlessly. And will accelerate rapidly, as the gravity trying to make it falls is far stronger than any atmospheric drag. It would, in a more realistic reality than this Clang's Universe accelerate you regardless of atmospheric drag to the point of you burning up. Because falling > drag.

    So we would burn up before we slow down. As long as the batteries last. Yikes. I guess we can be thankful Clang is a bit forgiving in at least this one aspect.
     
  10. Ronin1973 Master Engineer

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    There's gravity and there's friction. They are independent of each other but in the real world, they interact.

    The faster you travel, the more friction (wind resistance) factors into your acceleration. You will need more force to handle the friction.

    In the case of an object free-falling, it will continue to accelerate infinitely until it collides with the planet... the acceleration (not speed) will diminish until the force of resistance matches the force of gravity. The object will then reach terminal velocity. The shape of the object in direction of the acceleration will influence the resistance and terminal velocity. Drop a hammer and a feather in an atmosphere and note which one reaches the ground first.
     
  11. Calaban Junior Engineer

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    But a hovering lander tipped to one side is overcoming gravity with it's upward thrust. Which will also push right through any terminal velocity wind resistance... Terminal velocity is only the balance between free falling things. Not things with active thrusters pointed thataway
     
  12. FoolishOwl Apprentice Engineer

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    What infinite increase in acceleration?

    Acceleration is about thrust-to-mass ratios. But in practice, increasing thrust also increases mass. The resource requirements for increasing acceleration grow exponentially. "Infinite" acceleration isn't a possibility, and it becomes increasingly difficult to crowd on more thrust. This is complicated by the fact that SE doesn't have an aerodynamics model, so you also need more than one gee of downward thrust to gain altitude. Two gees of forward thrust is a fair accomplishment, but the advantage over one gee is barely noticeable unless you're using a speed mod.

    I can't see the developers wanting to massively complicate the physics model, to accommodate unlikely circumstances, that would only apply if you're using speed mods, which they don't recommend.

    A simpler fix might be if speed mods just had lower limits within atmospheres.
     
    • Like Like x 1
  13. CalenLoki Trainee Engineer

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    @Calaban terminal velocity is when forces that slow you down equal forces that speed you up. So it apply to either gravity or thrust fighting air resistance.
    Your lander with gyro fly sideways while tilting because thruster pushes it this way. Gravity can't push you sideways, because it's always pointing down.
    Gyro doesn't matter here, as it's the single one source of rotation. Without it, even tilted, you'll never flip over completely (unless you hit something or summon higher beeings). Because of oversimplified thruster mechanics in game - they apply force to center of mass, without any torque.

    @SirConnery I play with aerodynamic mod and it works as intended. But it does crazy stuff with sub-grids.

    @FoolishOwl Implementing basic drag mechanics is trivial. Just take amount of blocks facing each cardinal direction, then apply force equal to [surface area*speed^2*atmospheric density*x]. Or even use mass rather than surface area - even simpler.
    Devs just don't want to add it, for some other unknown reason.
     
  14. Ronin1973 Master Engineer

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    I think you could get a rough enough number from the surface area of each one of the six bounding box faces to get an amount of drag. While not accurate it might be passable. Having to calculate the total surface area for each of the six sides based on exposed surface area of each block might be a bit taxing. The bounding box already exists and is already calculated dynamically in the game. But I do understand your point and like it.
     
  15. CalenLoki Trainee Engineer

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    @Ronin1973 I don't think it's taxing. Run through all the blocks and save their grid coords into three lists (x, y, z). Remove duplicates. Get number of objects in lists. Done. And you need just three, as surface area from the back is exactly the same as from the front. Only multi-block objects may be a bit more tricky, but probably not a lot.
    I'd rather avoid using bounding box, as it encourage people to build flying bricks.
     
  16. SirConnery Trainee Engineer

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    Could such a mod be made where you have different top speeds in atmo depending on the amount of forward thrust/mass calculation of the grid? Just something simple so it doesn't tax the cpu.

    I'd really like to have a purpose for making long range vehicles, but right now you can reach top speed with any brick so they aren't needed.
    --- Automerge ---
    Also an unrelated question. At what speeds do the grids in SE start to act up? I've played with 300m/s big grid speed and 500m/s small grids and so far it's been fine. Is there a limit where the engine kind of breaks?
     
  17. SirConnery Trainee Engineer

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    So what I gather from here is that the things in real life that work against accelerating all the time in atmo are.

    1. Heat
    2. Loss of control surfaces being able to work from going too fast

    What I definitely don't want is shape of the craft effecting speed. My ideal mod would be heat accumulation stalling engines. The more mass you have more heat is produced. Then you could make lightweight ships made for flying fast.

    The aerodynamic mod has heat, but it just burns your ship down which is too punishing imo. Is there some way to mod the heat to just stall the engines?
     
  18. Spaceman Spiff Junior Engineer

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    Um-m-m-m...unless I'm missing something really, really basic, air resistance constitutes the major factor for speed in an atmospheric environment. Sure, given enough power to get enough speed, heat will then become a factor.
     
  19. SirConnery Trainee Engineer

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    Right, but given you have enough engine speed to get the thing off the ground and moving as I understand those 2 things are the major reasons why you can't just keep on accelerating indefinitely. Am I understanding this correctly?
     
    • Disagree Disagree x 1
  20. Spaceman Spiff Junior Engineer

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    Are you talking about in the game or in real life? My response to your comment, above, was because you said "real life". The game is different. Air resistance is ignored.
     
  21. SirConnery Trainee Engineer

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    I mean real life reasons. After you have enough engine thrust to battle off gravity and get acceleration, those 2 are the main reasons why aircraft don't just accelerate indefinitely. Am I correct in my understanding?
     
  22. Therolt Trainee Engineer

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    Lets see if I can construct some solutions that please everyone and make sense at the same time.

    Deceleration (drag) based on:
    • the surface area of one or multiple planes (front, back, sides, etc)
    • or alternatively, by a fraction of the total mass of the ship
    You could also factor in the current airspeed and altitude since atmospheric density* is already a thing in-game.
    Current fact: An atmospheric thruster outputs more force/acceleration at lower altitudes.

    With those changes and the current system:
    1. An object moving at 80m/s is subject to more deceleration than if it were moving at 40m/s
    2. An object at 1km altitude is subject to more deceleration then if it were at 5km altitude
    3. A 30 ton object is subject to more deceleration than a 10ton object
    4. A 30 ton object takes more force/energy to reach and maintain high speeds than a 10 ton object
    You would require a constant force to propel yourself forward in order to counter and overcome the amount of deceleration you receive.
    If you had a heavy ship with little thrust, the thruster's ability to increase your speed would cap out and as an example, it would be possible to have a ship with 80m/s top speed in its current configuration.
    It would be slightly harder to get out of the atmosphere but become easier once you're out since there is only the gravity well affecting you - so the solution only effects things inside an atmosphere.

    The result is essentially a gravity vector similar to a planet but it only effects your ship when you are currently moving and its magnitude scales with your speed and weight.
     
  23. SirConnery Trainee Engineer

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    Wow, that would be perfect.
     
  24. Stardriver907 Senior Engineer

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    Back in the early 70's when I was in college I got myself a pilot's license, which involved a quick lesson in aerodynamics. The gist is that when lift + thrust is greater than weight + drag, anything will fly. That's what the Wright Brothers figured out, and that's how it works to this day. SE does not have lift or drag, so the equation becomes thrust > weight = flight.

    What I have found confusing in your inquiry is the assertion that something in real life prevents you from accelerating indefinitely. i'm not entirely sure what that means. The short answer is that nothing stops you from accelerating indefinitely in real life. If you have enough thrust you can just go. There was a time when aircraft were limited to speeds of around 600 mph at sea level. This is because as the craft moves through the air, pressure builds up in front of the flying surfaces to the point where they no longer work and the craft falls out of the sky. 600 mph happens to be about the speed of sound, so they called it the sound barrier. In the 60's they knew that bullets traveled much faster than 600 mph so there must be a way. The surmised that if the aircraft had a lot of thrust and was shaped like a bullet it might work. That was the Bell X1.

    The next question was if you could go beyond the speed of sound, how fast could you go? That was the X15 project. The answer turned out to be that you could accelerate indefinitely as long as your aircraft could stand the heat. In other words, the limiting factors are how much thrust you can generate and what your craft is made out of.

    Having said all that, when I find myself flying a craft in SE there is little difference from the real thing, given that all lift is generated from thrust because wings don't do anything. I personally don't build "aircraft" in SE because the game does not provide the proper blocks and anything you make will weigh ten times more than it should (aircraft are not made out of steel). Instead I build spacecraft that can function in atmosphere, so I don't have to worry about aerodynamics.

    Some day Keen might make a spinoff called Aerospace Engineers and we will get materials like aluminum, titanium, and composites. Then we might get wings with control surfaces that need to be in motion in order to generate "lift". Even then the limiting factors will be how much thrust you can generate and how much heat can your craft tolerate.

    The game's "speed limit" is a consequence of how the game determines where you are at any given second. Generally speaking, the higher the limit, the greater the chance for errors. Keen capped speed at 100 m/s because that caused virtually zero errors and that's good when you are selling a game. There are mods that let you go faster and you use them at your own risk. They don't break the game, but moving at 1000 m/s might be a tad faster than you are prepared for, and some weird things like flying through an asteroid might happen. The big issue is stopping. Takes longer from high speed. A lot of people have been satisfied with a 300 m/s speed limit. To each their own.

    So I guess I'm not understanding what you believe in SE is different from real life?
     
  25. SirConnery Trainee Engineer

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    Hey, thanks for the longer explanation.
    I was just curious, since I don't know much about real life aircraft I was sure someone here did and could explain the real life limitations. Which as you said are heat and loss of control.

    I'm not looking to create a real flight model in Space Engineers. I just want achieving high speeds in to be harder in the game so you have some use for ships made for just going fast. If that just means stacking a bunch of thrusters I'm fine with that as well. Just so not any craft can reach top speed.

    Therolt's suggestion was perfect. I'm just not sure how such a mod could be created.
     
  26. Burstar Apprentice Engineer

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  27. SirConnery Trainee Engineer

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  28. Ronin1973 Master Engineer

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    A flying brick is already the optimum design. No one enjoys flying a brick. The game already has to cope with recalculations across the board every time a block is added or subtracted from a
    Atmospheric thruster efficiency would be a great variable to derive in-game drag from. There would have to be some sort of exponential modifier so that drag could be expressed as negative acceleration to your powered acceleration. With atmospheric drag/friction calculations, you could also add wind and wind-storms to the game capable of moving unanchored grids depending on the total amount of inertial dampener force available. That would be fantastic to play in, IMHO. The game really lacks dynamic environmental challenges. Plus watching a player get pushed across the map in rare hurricane strength winds would be kind of fun.
     
  29. FoolishOwl Apprentice Engineer

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    Some of us like flying bricks.
    [​IMG]
     
  30. Stardriver907 Senior Engineer

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    Yes, because it was supposed to be a space game where "environmental challenges" consisted of meteors. The real problem here is that atmospheric flight was not part of the plan from the beginning, and shoehorning it in after the game was really close to being finished just doesn't work. When you build a spacecraft in SE it generally works as expected except for the speed limit. Since the game did not have planets, orbital mechanics were not necessary. The real reason the game struggles to provide us with convincing aerodynamic flight is because it was and still is a space game. Stay off planets and you don't have to worry about aerodynamics.

    If the original intent was to have a game for building aircraft, I have no doubt that Keen would have produced the most realistic aerodynamics possible on planets, at which point the players would have insisted aircraft should be able to operate in space, and you would need mods to do so convincingly.

    Seriously, Keen needs GoodAI in order to figure out how to make a multiplayer game that does both well.
    Every single one of my ships is a flying brick, and I enjoy flying all of them. But, I fly them like spacecraft, not aircraft ;).