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Please Add Realistic Aerodynamics (FAR) and Perhaps Procedural Nozzles for Optimizing at Different Pressures

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On 7/17/2021 at 10:49 AM, AlmightyR said:


It's not impossible: Multiple other games have done it. (War Thunder, ...

I feel the unnecessary compulsion to point out that War Thunder does not in fact have multiple aerodynamics models applying themselves differently to every plane, they have 3 different sets of stats for each plane for each mode, that is slightly tweaked to give better balancing and closer to realistic flights. In other terms:It's a lot like sticking 3 extra pairs of wings in your fuselage for an "arcadic" experience, and just removing them if you wanted a "realistic" experience without FAR.

Edited by Missingno200
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9 hours ago, Lt_Duckweed said:


It's ok to have a high skill ceiling, but it needs to be based on clearly designed and laid out game mechanics, not strange arcane exploits that live only in the minds of vets and in secluded discord servers.


Gosh i wish i had more than one like, because this is a golden nugget for the archives.

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On 7/19/2021 at 9:53 PM, TLTay said:

Would KSP2 need a different model for hydrodynamics? Or would it still be able to use the aerodynamic model for underwater work?

A single model would work for atmosphere and ocean, taking into account the different density of air, water, etc.

There is tricky physics at the air-water surface: wave drag and hull speed and planing.   KSP1 ignores all of that, except for buoyancy..

 Water is about 800× as dense as air, so at a given speed, the water forces on wings and control surfaces would be 800× as strong as aerodynamic forces.  More likely, the speeds through water lower by a factor of 30.  (KSP1 reduces the hydrodynamic forces, by the factor  buoyancyWaterLiftScalarEnd = 0.025 in physics.cfg, so water forces are only 20× as strong as air forces, at the same given speed.)

KSP1 also has several other adjustable parameters in physics.cfg.  Some are apparently for making splashdowns look believable.  There is an artificial extra drag that, as I remember, was added to more quickly bring the velocity of a capsule below 0.1 m/s so it could be recovered.  Better, I think, would be to let us recover 'splashed' craft while they are realistically drifting through the water.   FAR is also rather messy and arbitrary in its treatment of water.

I was frustrated trying to deal with these more complicated rules when building submarines  with KSP1.

Edit:  If buoyancy from hydrodynamics also applied to aerodynamics, that could be a natural way to simulate bases floating in Eve's dense atmosphere.

A FAR-like evaluation of the shape of the entire craft,  might also evaluate the buoyant volume.   (Finding the centre of buoyancy at each depth, is similar to the evaluation of sections that FAR does to evaluate area ruling.)
Players could then clip parts to express the tight packing of a dense submarine, or sparsely fill a fairing to make an Eve airship.

Edited by OHara
more thoughts on buoyancy
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On 7/19/2021 at 11:30 AM, Deddly said:

1) KSP should have FAR and only FAR from day one

2) KSP should have the regular aero model and FAR should be added later as a toggle

3) KSP should have the regular aero model only, and FAR should remain a mod as it is today.


But there is a forth alternative some have argued for or painted others as arguing for:

4) Regular aero model, AND a FAR-like model as a toggle, at launch rather than later.
(overkill, IMO)

On 7/19/2021 at 11:30 AM, Deddly said:

recognise that each alternative is just as valid as yours

On 7/19/2021 at 11:30 AM, Deddly said:

so I would be over the moon with either suggestion 1 or 2

I disagree that each of the alternatives are just as valid as any other, and have largely already pointed out and explained their differences, advantages and disadvantages, in my opinion.

I disagree particularly with #1, as, to me, that is by far the worst option. The only advantage I can see with it is that it's the best for people who like a FAR-like model (and to be clear, I'm one of them; FAR is a must-have on my KSP1; but that's KSP1; a game I also played without FAR for years); but then it's cancelled out by being the worst for everyone else. And at that point, I see no good side to it.

But I thank you for at least presenting your point in a nuanced, respectful manner, without misconstruing anyone's argument.

And I'm along side you in that I would be ecstatic with happiness if a FAR-like model was implemented a secondary model with a toggle on the official game. Exactly as you said: Probably not going to happen, but we can dream.

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On 7/19/2021 at 3:45 PM, Lt_Duckweed said:

2 wildly different aero models supported at the same time has a pretty much 0% chance of happening.

Almost zero is not zero. Even the "almost zero" part is debatable: It really depends on the community and the community pressure for it.

On 7/19/2021 at 3:45 PM, Lt_Duckweed said:

1. Developing 2 different models costs dev time (and therefore money)

Agreed. But that is not a problem as long as the devs expect to profit more out of implementing than they expect the cost to be. Again, community pressure for it is a big factor there.

On 7/19/2021 at 3:45 PM, Lt_Duckweed said:

2. 2 different methods have to have all their interactions regression tested with every release (costs money)

Technically true, but functionally false, IMO. Automated testing is an integrated part of development nowadays and doesn't need to be reimplemented from scratch for every release. It has a very small footprint overall, and a microscopic one between releases, to be honest.

On 7/19/2021 at 3:45 PM, Lt_Duckweed said:

3. 2 different methods means twice as much surface area for bugs. More bugs to fix, harder to diagnose (costs money).

Again, technically true, but functionally false. And if you put it into perspective, since a large portion of KSP1 players use FAR, a FAR-like secondary model is pretty much guaranteed to be implemented to KSP2 through mods if it's not done by the official team, and so you're still dealing with the same problem here, because the "surface area for bugs" is equal at best, and greater at worse; as is the difficulty of diagnosis; through an external 3rd-party implementation. This is basically hot-potato'ing the problem to a different set of hands, and then claiming "not my problem". Not a realistic  criticism of the idea, IMO.

On 7/19/2021 at 5:53 PM, TLTay said:

Would KSP2 need a different model for hydrodynamics? Or would it still be able to use the aerodynamic model for underwater work?

As @OHara already pointed out in a different way, most of the interactions are dealing with fluid dynamics (name is misleading; it applies to gasses too); and so the same model applies well for interactions with both water and air for the most part, with some caveats at special points like buoyancy and density.

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My (somewhat unorganized) two cents on the topic.

Whatever Take Two decides to implement, there should only be one stock aero model.  On the dev team, and on the players, that would make everything easier to facilitating development, creation, usability, and sharing of crafts.  That being said, the aero model should not be what's implemented in KSP1.  I've only recently dabbled in FAR, but one of the things that stood out to me was the drag model.  At a minimum, KSP2 should have a more realistic drag model that gets rid of weird exploits and doesn't force you to think about drag in a non-intuitive way.

An example of what I mean about the drag model:
When making replicas, there is often the need to clip parts everywhere to get a shape just right or for whatever reason.  Or it could be a customized cargo bay for a spaceship, where parts that should be shielded from drag are experiencing drag.  This causes things like people creating rather OP engines (BDA Saturn) when in reality, instead of extra thrust, there needs to be less drag.  As a side note, I'm pretty sure this is what the node attachment drag thing was meant to fix, but obviously people surface attach things too.

On the OP engines such as the Saturn from BDA, by countering excess drag (that shouldn't even be there) with thrust, the thrust makes other aspects of the craft which rely on TWR very unbalanced.  I, for one, tend to believe that more realistic = more balanced.  Not only that, but enhancing realism should make some things intuitive for new players (attaching parts to a backwards node and flipping them around is one example of something new people would not think of, and is only done as a workaround/cheat of the physics system).

With all I've said about realism, I don't think that the FAR-level realism is necessary.  Sure transonic flows and whatnot may be an interesting read, but most people will be interested in going to space.  They'll probably experience it for a couple seconds when their rocket with 50 boosters first launches on a Mun speedrun challenge.

Worst comes to worst, the aero model is like KSP1 and a FAR type mod will come out for KSP2.

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