Veld
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Posts posted by Veld
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Ah ofc silly me
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22 minutes ago, MookMcMook said:
Ah thanks, I was consulting you and I guess you have to consult the variables! The orange curve:-
Nice info but wow that's a mouthful. I must confess I'm not a physicist; I'm an engineer. Albeit a self proclaimed engineer. Looked up the "Gaussian well" and got a bunch of quantum mechanics (which I am terrible at and avoid at all costs). But for me it's not the intrinsics that count- it's the observed effects. This basically means the orange curve describes a field with a point in it that will repel objects entering the zone. Anything caught in the 'distortion well' that has no forces acting on it other that gravitational pull will oscillate around X=34 until it becomes stationary relative to the generator. This will be enough to add to my post on how gravity might work but I have one concern: I believe JC used Desmos to make his graph and there is a certain mathematical operator I don't understand here. That little dot between the expressions.
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47 minutes ago, MookMcMook said:
OP you did see this:-
Yes I did but it means pretty much nothing to me. Way too many variables; no explanation. Although if I stare at it for a while I might be able to figure something out. One thing you can tell right off the bat is the green line represents a conventional curve of gravitational force against distance. So f(X) is probably force and x is probably distance. Maybe something to do with the size of the block in there but I honestly have no idea. Once I can play around with them it will make sense eventually.
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Actually just realised the field strength is in fact diminishing. Added it to the post. Here we can see the acceleration on the vessel is 0.5g with no forces acting on it other than gravity. Diminishing, but diminishing by what law is still indeterminable for me as of now.
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33 minutes ago, MookMcMook said:
Also, what is the coefficient of gravity acceleration in the above OP post @Veld "n" I don't recollect small "n" at all? Perhaps it was in physics beyond what I studied at at school?
Sorry should have elaborated on the terminology I was using. In the game the acceleration due to certain forces on your vessel are given in terms of g. Hence the numbers they give you are a "coefficient of g for acceleration". I just made it up to describe what they were doing.
Here:
the value of n is 7.3 for example
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5 hours ago, AzureSkye said:
I'm impressed! That's a lot of quality deduction from one video
Thanks. More to come soon perhaps.
5 hours ago, AzureSkye said:As far as I'm aware all astrodynamics in the game will be a consequence of the underlying physics engine.
So that's to say that celestial bodies move around in orbit of their stars, planets etc.?
5 hours ago, AzureSkye said:Notably, constructs won't be able to exert gravitational influence on voxels.
Understandable. Every voxel being calculated over is going to be a huge strain.
5 hours ago, AzureSkye said:Unlike Space Engineers ( /r^7), gravity should be falling off naturally ( /r^2), but I could be wrong there.
Interesting. I'll need to test it but not before I understand how orbital mechanics applies to the game more. If they do apply I'll make a circular orbit and relate the centripetal force equation to the gravitation equation to see if they apply. Although I need to know the mass of the planet somehow. Need to think about it more.
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15 hours ago, CalenLoki said:
I bet they'll just set some "geostationary distance" and down pulling force will get gradually reduced from planet surface to that artificial orbit. So FtD style.
And similar "atmosphere range", affecting air drag and atmo-engines efficiency.
Simplest, cheapest, easiest for players to understand.
Maybe not the most realistic, maybe not the most rewarding for hardcore engineer nerds, but it's a game.
I've figured out that you can orbit the planet, alioth, normally from the videos. Therefore there's no need for a "geostationary distance" where there is no gravitational pull. But I do suspect they will terminate gravitational fields for planets at select point and won't make them orbit around the sun and such because that would get too complex.
The thing is the delta-v generated by the engines/fuel is so massive you can just make for the moon from alioth in more or less of a straight line so players will find it pretty easy but the diehard physics nerds will be able to maximise efficiency. Then again I might be wrong. I am just making speculations off pre-alpha footage.
Edit: the moon is also pretty close and the planets are pretty small too.
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4 minutes ago, Atmosph3rik said:
But I'm sure there will still be times that voxel lettering will be useful.
Yea can't to tow a giant "JEAN IS BAE" sign into orbit
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2 minutes ago, Lethys said:
Saving 2 voxels per Word since 2018. Rock on
You have 150 ships rolling around advertising stuff with this font on various planets. Each has 3 words on them. 150*2*3 is 900. That's 900 voxels you could be saving your corp rolling around just for advertising. Maximum quality control and maximum efficiency is the ultimate goal of a designer in a corporate scenario.
- Atmosph3rik and Loglyn
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On 24/06/2016 at 7:00 AM, Archer said:
The point I'm trying to make here is that if you have to worry about orbital mechanics then you will not have dogfights with visual range weapons. Imagine being on a wide open plain with no effective places to hide armed with nothing but a sword. There is someone else on that plain with you, also armed with a sword. If you try to chase him down you'll be able to close part of the distance, since there will be a delay before he sees you and decides what to do, but if he doesn't want to fight then he has plenty of time to run away. If he has the same endurance as you do then you'll never catch him; if you're both equally stubborn then you'll both collapse from exhaustion at the same time and you'll never actually get a swordfight. Now replace the sword with a gun. You still have to approach him but you don't have to get as close as you did before, just close enough to take the shot. That gives your target a much smaller window to start running before he finds himself in your gun range. Of course you still don't get into a swordfight; now it's a gun fight with all the tactics that involves. It also doesn't guarantee that you'll be able to get close enough but it does become a lot more likely. Likewise, with orbital mechanics and remotely plausible distances and speeds you'll never be able to use visual range weaponry effectively, you'll need something that can hit a target from thousands of kilometers away. Throw out orbital mechanics, set all movement relative to a stationary reference and confine the playing area to a smaller region (either by having some stationary point of interest players are likely to gather around or limiting the playing field to a small area) and you might be able to get away with shorter range weapons.
Necroing but good topic so might as well.
DevisDevine is right. Intercepting in over long distances in space is no different than intercepting over short. The calculations are just more complex. You just need to be able to understand the trajectory of the target vessel, make a transfer orbit, constantly accelerate along the prograde vector to get there faster if you so choose and account for any changes in your targets velocity. It's all a question of who has the fastest vessel.
In real life we use transfer orbits for most efficient use of propellant. So instead of accelerating along our trajectory we choose to wait for the ideal alignment.
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8 hours ago, Lethys said:
?
Just write the way you like it ?
Technically you could design a font that minimises the amount of voxels used but still looks pretty. Therefore saving you money. So it would be the most logical option.
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Haven't seen a lot of physics talk going on so I thought I'd start a thread. Might be too early in development for this but I'm going to do it anyway. I'm going to break this up into separate posts because there's a lot to account for here. There's some discussion going on between the posts so just skip through and find my numbered and titles posts to see the full info in one place.
1: Investigating gravity and other values
In the video on atmospheric flight we can see certain values, given to us or expressed as variables, specific to the vessel and the environment:
Misc. values
- Altitude
Presumably in m above sea level given the altitude in the above pic
- Mass
In metric tons judging by the change in mass, in kg, shown above. Thus 1 ton = 1000 kg
Forces
Looking at forces in the vertical plane we see:
- Lift = 7.3mg
- Force up = 8.3mg
- Weight = mg
In the real world aerodynamic lift is a force due to the airflow under the wings of an aircraft. In this game this is not the case as the guy in the video said the vessel would have no lifting capability if there was no vertical booster. However, aerodynamic lifting parts are to be added in future: click here. Let’s look at the free body force diagram (not to scale):
Here we see Force up - Weight = Lift. This means lift is in fact the resultant force on the vessel going up. There is clearly no aerodynamic lift as if there were: Force up - Weight = Lift + Aerodynamic lift. Also this diagram shows us that g is the same for the values of acceleration given for the vessel and for the gravitational field of the planet (it would have to be a pretty hard coincidence if the difference in the values of g was making up for the apparent absence of some sort of aerodynamic lift). Another thing it shows is that the acceleration value next to the force (i.e. 200 kN/ 8.3 g) is the acceleration due to that force itself and not the resultant force on the vessel.
Finding g
So we can find the true value of g by rearranging F = ma = mng to g = F/mn (where F = force, m=mass and n = the coefficient of g for acceleration)
Using the forwards and upwards forces as input, their respective accelerations and the mass as 2 ton the two values of g we get are (to 4sf):
12.04 and 12.20 ms^-2
Averaging at:
12.12 ms^-2
It still feels a little weird having the value of g as around 12 when the whole purpose of expressing the acceleration of the vessel in g instead of ms^-2 is to make it more relateable.
The thing is the uncertainty in the value of mass is 25%. Because it is rounded to 1sf it can be anywhere between 1.5 and 2.5 ton:
Doing the calculations in finding g again, using the upper limit of the mass (2.5 ton), we get the values:
9.639 and 9.756 ms^2
Averaging at:
9.698 ms^2
That's pretty close.
Pretty wishy washy considering the certain info: In this video (06/042017) we can see a vessel reaching what the guy describes as "escape velocity” and then proceeding to perform some sort of orbit around the planet. Whether this is some form of pseudo-orbit or a proper orbit is debatable. The guy in the atmospheric flight video also states that if we have enough initial velocity on burnout we can escape the gravity 'reel' and orbit. Otherwise we fall back down. The thing is in real physics the term ‘escape velocity’ describes the initial velocity needed for an object to escape the pull of a gravitational field altogether. It’s unclear what his terminology is describing. He also implies that the engines on a craft need to be turned off for it to start orbiting. But we can clearly see his vessel in its ‘orbit state’ has acceleration of 0.5g and is moving at increasing speed. This means he is in an eccentric orbit and the field strength diminishes with distance, meaning one can alter their orbital trajectory and orbital mechanics is a thing (at least in the context of a ship around a planet- needs stronger affirmation). In the context of the video he is moving from the apoapsis to the periapsis as he is speeding up.
From a tweet on anti-gravity generators (discussed later) we find a simplified equation for the diminishing effect of gravity with distance:
The real equation for the acceleration is:
(in the context of NQs equation r would be x)
(G=gravitational constant, M=mass of planet, r=radius from core)
But at NQ they don't have time to be thinking about the average density of a planet for its mass or the gravitational constant. What they do is simplify the right hand side of the expression (GM/r^2) to other values to make it have the same dimension. Instead of GM the constant of proportionality is gr0^2. Which gives the same dimension of ms^-2.
Evidence of pseudo-gravity can be found in this video (05/07/2017) but will be discussed in later topics
In this video (18/07/2016), looking at the space station, we can see why there would be no spin on the planet and it isn’t orbiting the sun (that is assuming they haven't put the station in a geostationary orbit which I doubt they have). This is because the station is stationary and uses static cores (it is quoted to be 5km long so too big for dynamic core ships) as opposed to the dynamic ones for ships. NQ says (24/09/2016) they will add planet spin in the future though. But currently they use a rotating skybox. Also see this DU wiki quote:
“Currently, planets do not rotate on their axis, but this feature may be added at a later date. However, planets will never orbit around their stars, for technology and gameplay reasons.”
If spin is added, space stations cannot simply be static. However, if not added they can work fine. A docking ship can simply use its VTOL thrusters in braking its orbital velocity to prevent itself falling to the planet.
Here we see a discussion on the fb page. This suggests static constructs in orbit will be an exception or a dynamic construct can be linked to a static construct to help it move. The latter makes sense as you would need a starting voxel to build off in space.
Another speculation is anti-gravity fields could hold constructs stationary instead of orbiting. See anti-gravity section for more details. However, the tweet where JC was working on antigravity is dated to 2018 whereas the static orbit video is dated to 2016. So it is unlikely antigravity was developed by this point.
Antigravity according to DU
We don’t know exactly how antigravity will work but we know how it might work.
Here we can see some of JC’s tweets on the matter. He has made some curves in desmos representing the effects of antigravity. One thing you can tell right off the bat is the green line represents a conventional curve of gravitational force against distance. So f(x) is probably force and x is probably distance. The first half of the equation previously discussed relates to the green line.
He has also explained the orange curve. It describes a field with a point in it that will repel objects entering the zone. Anything caught in the 'distortion well' that has no forces acting on it other that of gravitational pull will oscillate around x=34 without stopping unless placed perfectly on x=34.
The second part of the equation is mostly maths and does not have much to do with physics. By adding a gaussian function to the standard gravity field you are able to create a given area where g is negative (anti-gravity). The thing is you want it to be on a specific location. As if the anti-gravity function were simply a negative gravity function you would start with infinite acceleration at 0 displacement and that's why you use a gaussian function.
The function as a whole effectively simulates a planet. r0 is probably the radius of the planet which creates this field and h the altitude from the sea level of this planet. So r0 +h is the distance from the core of the planet and from the graphic, in this case, it values something around 32 (kilometres I guess). In the exponential term, s is a term that indicates how far across the well is and a indicates how deep the well is (the magnitude of negative acceleration produced by it).
So by choosing r0+h you can set where you want your gravity well to be, choose s to set how large it is and a to set how deep it is. If you want to have anti-gravity (so that the function is negative somewhere), you have to choose a wisely. If you choose a=0, then you have the standard field of gravity (the green curve). The well does not have much effect for small values of s.
The function also could represent the field around planets in game for space stations to achieve ‘static orbit’. The point is to make the gravity field being zero at some points. Then in these points you will no longer accelerate toward the planet and if your velocity is zero then you will stay on these points and so you are able to have an ‘floating’ station without needing it to have angular velocity (as it's supposed to be built using static cores in the game). But by doing this you have to place your object very accurately otherwise it will oscillate indefinitely around the point (depending how far you placed the object from the equilibrium point supposing that the gravity field is the only force). So it is likely they will introduce some friction (or anything that dissipates energy) to stabilize the position.
Conclusion
- g is probably 9.81. It makes sense from a design POV, being the same for the planet and for the expression of the acceleration.
- In the future we could see differing values of g for different celestial bodies causing different lifts.
- Further, more controlled testing can affirm the value of g but through mere speculation (Trusting NQ is consistent in their game design) we can assume it to be 9.81.
- Instead of going by the mass given in the engineer report, for more accuracy in your calculations use: m = F/g(1 + L) where F = force up and L = the coefficient of acceleration due to lift
- I'm pretty 50/50 on whether NQ will add realistic orbital mechanics to the game as the evidence points to no clear conclusion. Will have to await more updates and to get myself into alpha 2 to do some tests. Keeping Newtonian mechanics to the basic level until further confirmation.
- It is unclear as to how NQ plans to manage space station orbits as of yet. But they will orbit normally for sure.
- Antigravity presented in the context of JC’s ‘orange line’ seems like it is supposed to hold objects in ‘stasis’ around a point. However, if this point moves the object in stasis will jiggle about accordingly. So it may be for ‘static orbits’ but needs polishing first if so.
- The g against r equation from the tweet is highly suggestive of diminishing fields and itself being the equation to be used
- MookMcMook and Sunrider44
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Possible exploits and ways to prevent them
in General Discussions
Posted
On the subject of underground bastions:
People are talking like taking the bunker directly by force is the only option. I don't know if any of you have read 'the art of war' by sun tzu, but in that he talks about weak points and strong points and how it is best to simply avoid the enemy if you don't have the resources to be able to defeat them. The ultimate goal in war is to defeat your enemy with as little fighting as possible. You shouldn't even engage in war in the first place if the odds are against you.
Other than direct means of engaging in battle, you can use many ways to take out a base:
These are just general tactics you could use. In a real situation the enemy is unique and has their own strengths and weakness/ disposition you can use to your advantage. There are also strategies the enemy can employ to counter you, but I won't go into that. The point is, in war, the smarter, more flexible guy wins
"Water shapes its course according to the nature of the ground over which it flows; the soldier works out his victory in relation to the foe whom he is facing" - Sun Tzu
The thing is NQ want us to compete with one another in innovative ways. They want us to take control on how we choose to fight only giving small nudges when the going gets stale. Before claiming certain strategies in game are exploits; wait to see how they play out first. If they become meta, NQ will take appropriate action.