"Far is hard"

[SAI Peregrinus]

Because it's very difficult mechanically and very dangerous to do when there is an actual risk of failure (you are adding more failure paths). Only one rocket will have cross-feeding fuel from boosters to core and it hasn't been built yet.

It's also not done because it's effectively impossible to pump the fuel around fast enough, which leads to your point. One of the most common failures of rockets that makes them explode is a turbopump failure. With asparagus staging, you need an extra turbopump per sub-rocket. And it has to be big, to pump fuel fast enough... which adds even more weight.

Fuel lines are ridiculously OP in this game.

On the main topic, I find FAR easy. It's more intuitive than stock aerodynamics, and the fancy simulation windows make it very simple to get things right before leaving the SPH, which is a nice benefit. They're the main reason I don't like NEAR. I want to be able to get at least the major design aspects working before I test a craft, FAR (and Kerbal Engineer) helps with that.

[skrit manfrat]

I tried FAR in an attempt to get some actual aerodynamics in the game, this is how it went

-planes reacted and flew better, had the capability of stalling, i was pleased.

-rockets suddenly became EVEN EASIER

this is primarily a rocket game for me, so making the already too-simple rocket mode even easier was unplayable.

so i thought to myself, "no worries, i'll just install RSS and ISP balance mods and we'll be away again, playing the game like it should have been."

-game is unplayable, crashes every 5 minutes

-ragequit, uninstall mods, cry myself to sleep

[bac9]

This a very good thread, thanks for taking the time to put it up, PDCWolf. I have to agree that FAR is easier for me, and, more importantly, I'm of opinion that it's fundamentally a better choice for new players, as things looking like real planes actually fly like real planes when you have a proper aerodynamic model. Making aircraft design more intuitive is an undeniable benefit. I also think it's important to look at the difficulty in combination with design depth and potential for fun gameplay. If some system adds a bit more challenge to the craft design process but enriches it with branching, meaningful design choices (for example, making previously completely ignored wing shape or rotation meaningful), I can only welcome such a change. Puddle-deep mechanics are not necessarily easy and most definitely can't provide lasting fun.

Edited January 15, 2015 by bac9

[Jouni]

That's bull. No other way to put it. It takes just as much time building a rocket for launch in FAR as it does in stock, the emphasis is just on weight and fuel balancing rather than running fuel lines in confusing configurations, and in the end your rocket looks like a rocket instead of a bunch of toilet paper rolls.

Building large rockets takes more time than building small rockets. Stock rockets are about 2x bigger than FAR rockets for the same payload. Also, nobody forces you to build ugly rockets in stock.

Only problem is that in stock KSP, there is no way outside of using docking ports to connect pieces in orbit, and docking ports don't make for stiff connections.

Docking ports make good enough connections that you can push a 750-tonne payload with seven KR-2L engines at full thrust. You just have to use more than one of them.

[Alshain]

Building large rockets takes more time than building small rockets. Stock rockets are about 2x bigger than FAR rockets for the same payload. Also, nobody forces you to build ugly rockets in stock.

The game does force you, you just said it. 2x bigger, to me that's ugly. With FAR you have to be more careful not to front load your rocket or you will be doing somersaults... yes I know you have to do that in stock too but it's a bigger problem in FAR because the air will push your craft around. You also have to be careful that everything can be aerodynamically shielded. That takes extra planning adds more time to the construction. I used to launch elephants on the head of a pencil in stock and almost never lost control. If anything, FAR takes longer to construct my rockets.

Edited January 15, 2015 by Alshain

[Jouni]

The game does force you, you just said it. 2x bigger, to me that's ugly. With FAR you have to be more careful not to front load your rocket or you will be doing somersaults... yes I know you have to do that in stock too but it's a bigger problem in FAR because the air will push your craft around. You also have to be careful that everything can be aerodynamically shielded. That takes extra planning adds more time to the construction. I used to launch elephants on the head of a pencil in stock and almost never lost control. If anything, FAR takes longer to construct my rockets.

I actually find stock rockets too small, especially if they have payload fairings. Giant fairings on top of a small rocket look really ugly. Reducing the typical payload fraction from 15% to 5-10% would make the rockets look much better.

And there's definitely no need to be careful when designing rockets for FAR. Here are two examples of rockets that are perfectly capable of reaching orbit:

[Camacha]

You can do some crazy stuff with FAR, but as always you need to walk before you can run.

[NBZ]

FAR is hard – on the processor.

The computers I have available simply are not up to the task of doing the more realistic computations, as opposed to the stock ones, an issue HarversteR briefly mentioned:

So whatever solution we come up with must not only fit the gameplay requirements above, it must also be computationally viable to not reduce the game into a slideshow.

I currently use Stock Drag Fix, but I would prefer something based on shape, not (empty) mass.

[PDCWolf]

FAR is hard – on the processor.

I don't have my tests at hand, but really, FARs footprint is almost nonexistant. I'll find or either redo my test and add this one to the OP, thanks for reminding me this excuse exists

[bdito]

As far as rockets are concerned, I find FAR isn't as difficult as people believe it is. Just make it aerodynamic (ie, put on fairings or nosecones) and keep your TWR and angle of attack reasonable. That's it.

[smjjames]

I tried FAR in an attempt to get some actual aerodynamics in the game, this is how it went

-planes reacted and flew better, had the capability of stalling, i was pleased.

-rockets suddenly became EVEN EASIER

this is primarily a rocket game for me, so making the already too-simple rocket mode even easier was unplayable.

so i thought to myself, "no worries, i'll just install RSS and ISP balance mods and we'll be away again, playing the game like it should have been."

-game is unplayable, crashes every 5 minutes

-ragequit, uninstall mods, cry myself to sleep

What's your idea on making the rocket mode more complex?

[Yemo]

FAR is hard, because it is not intuitive and the cd value is not derived from the shape of the parts.

The cd value is just derived from the value of the FRONT parts.

Want to make a low cd rocket? Just take a 3.75m part and place low cd value parts (eg winglets, nose cones) on top of it.

For every low cd part on top, the cd value of the "rocket" will go down. No matter the shape or anything else.

Eg a 3.75m diameter part alone results in a cd value of around 33, put one! 1.25m fairing base somewhere on top of that 3.75m disc, facing the other way around, and the cd value goes down to 0.5!!!

If I use a procedural nose cone, it has low cd value, if I use a procedural structural element with exactly the same pointy shape, I have a cd value as if it had a flat front.

If I put two 400 batteries under a nose cone, it raises the cd value, although they are completely covered.

If I accidently forgot to decouple my procedural fairing base ring just below the capsule, I crash into the ground, because it turns out, the 1.25m procedural faring base ring beneath the capsule has a lower cd value than a nose cone. Even though directly after it sits the whole heatshield of the capsule.

If I put a magnetometer from DMagic Orbital science directly on top of a 1.25m part, it acts like a nose cone for the cd value, although it covers only something like 0.375m of the 1.25m diameter, the rest is still flat.

If I put on the RealChutes nose cone, it doesnt matter how large I make it, the capsule gets a worse cd value than one with a very similar shaped nose cone and 2 radial parachutes!

Edited January 15, 2015 by Yemo

[Naito]

Honestly I find building planes with FAR much more intuitive and fun than doing it in stock. Stock makes no sense aerodynamically. I'd love to have FAR stock, and then just have the aerodynamic failure turned on or off depending on selected difficulty level. Hard mode should integrate Deadly Reentry as well!

[ferram4]

FAR is hard, because it is not intuitive and the cd value is not derived from the shape of the parts.

The base drag for a part is. However, there are other factors used for part interactions, and those are the problems you're seeing.

If I use a procedural nose cone, it has low cd value, if I use a procedural structural element with exactly the same pointy shape, I have a cd value as if it had a flat front.

Because FAR uses an unused attach node as an indication of a highly blunt face. In theory, this would work out great, if Squad hadn't used the size 0 node for non-radius 0 parts.

If I put two 400 batteries under a nose cone, it raises the cd value, although they are completely covered.

If it's just behind the nosecone, then that doesn't mean anything; they can still have an affect on the recirculating flow. If you're clipping parts together, then that's something that I can't detect, without making everything a lot laggier (and neither will Squad), which is why I tried to convince them to not enable part clipping by default.

If I accidently forgot to decouple my procedural fairing base ring just below the capsule, I crash into the ground, because it turns out, the 1.25m procedural faring base ring beneath the capsule has a lower cd value than a nose cone.

This is actually a legit problem, one that needs to be there because of that insane method KW Rocketry uses for attaching fairings, which results in tons upon tons of attach nodes. Turns out it's difficult to differentiate those from the ones elsewhere.

If I put a magnetometer from DMagic Orbital science directly on top of a 1.25m part, it acts like a nose cone for the cd value, although it covers only something like 0.375m of the 1.25m diameter, the rest is still flat.

Also a legit problem, one that could be fixed very very quickly by ensuring that the correct node sizes need to be connected in order for all drag to be cancelled. Problem though: mod packs rarely, if ever, set their nodes correctly. A possible solution is to instead try to get size from the part mesh, but that leads to issues for parts like the quadcoupler where you're trying to detect and allocate a common area among many nodes. Not really easy, and lots of edge cases. Also, that method is laggy as all hell, hence why it isn't implemented yet (incidentally, this would fix the payload issue as well).

If I put on the RealChutes nose cone, it doesnt matter how large I make it, the capsule gets a worse cd value than one with a very similar shaped nose cone and 2 radial parachutes!

This one isn't my problem, RealChute does its own thing entirely that I have no control over. Don't blame me for another mod's behavior, I get enough of that already.

I'm sorry that it isn't perfect. I'm sorry that I try to maintain compatibility with as many mods as I can. I'm sorry I care about trying to do this without lagging the game to hell. This works for 95% of the situations people find themselves in, with only a few oddities remaining.

The cd value is just derived from the value of the FRONT parts.

Want to make a low cd rocket? Just take a 3.75m part and place a lot of low cd value parts (eg winglets, nose cones) on top of it.

For every low cd part on top, the cd value of the "rocket" will go down. No matter the shape or anything else.

Eg a 3.75m diameter part alone results in a cd value of around 33, put one! 1.25m fairing base somewhere on top of that 3.75m disc, facing the other way around, and the cd value goes down to 0.5!!!

Methinks someone needs to check out the reference area being used. D = 0.5 * density * velocity^2 * area * Cd; increase the reference area, and it's effectively the same as decreasing the Cd. You should see some of the rockets you'll fly, with huge reference areas, because FAR uses surface area as the reference area to make skin friction drag easier to calculate. You were doing so well with criticisms until you edited that in and showed that you really aren't running the numbers.

[smjjames]

Uh, what's a cd value? center of drag?

As for the whole cd value not being realistic, you'll have to talk to ferram about that, and is the big text really neccesary?

Edit: nvm, ferram answered you.

[Alshain]

That all just illustrates that FAR isn't complete realism like so many of the naysayers claim. FAR is simply a better approximation than Stock.

[Yemo]

@ferram4:

Sorry if that came around as bashing FAR or yourself, it was not meant this way, thats also a reason I didnt post that in the FAR thread.

It was a post about a reason why FAR is hard, not why FAR is bad.

And non-intuitive makes it harder to use a mod, regardless of where the non-intuitive parts come from.

In my mod (SETI-BalanceMod, where using FAR is recommended in the first post), you start with probes. Unfortunately, the altitude contracts can not be completed with probes, only manned vessels count. This is a bug from SQUAD (either remove the manned restriction or mention it in the mission text), I cant mod those "story" missions and since you start manned in stock, it is unlikely that this bug will be corrected.

That makes starting with probes hard, users will waste a lot of funds and probes and do not know why they cant complete the missions.

As modders, we have to build upon that which is provided, from information to restrictions. And often enough finding a compromise between vision and restrictions is a dilemma.

I just put a big red line under my download link, to warn people about the inability to complete altitude contracts with probes.

And I just lost a Kerbal, since I placed a procedural fairing base between capsule and decoupler, not below the decoupler, the resulting low cd value let Jeb crash into the ground and the last save was corrupted...

So I put this giant red text in this post.

I m sorry my post was worded this badly, coming around as such a bad criticism of one of the best mods of KSP, and even as a criticism to yourself, which was certainly not intended.

FAR is one of the defining mods for KSP and I greatly appreciate your work!

Modding is often hard and a lot of work and such a bad post can ruin the mood, I m very sorry about that.

Edited January 16, 2015 by Yemo

[kujuman]

I'm on again off again with FAR. I love having flaps and airbrakes and percent responsiveness to different axes on control surfaces, but it's such a chore considering how annoying other parts of it can be. My mates shuttle has many of these annoyances. Split rudder airbrakes? Sure, they work great on the runway. They work great in low alt testing. But they give a rudder hard over when trying to fly reentry, every time. FAR's drag by node is kinda a pain with certain shuttle designs, where there are a lot of large nodes at the end (engines, radially attached girders etc). Figuring out proper camber and thickness on delta wings is...hard.

FAR isn't "hard", but it is time consuming. And it makes designing things to look good hard when so many parts have unlogical CoM already.

But when it works right? And your time pays off? Amazing.

[lincourtl]

FAR is hard – on the processor.

The computers I have available simply are not up to the task of doing the more realistic computations, as opposed to the stock ones...

I'm running KSP 0.90 with FAR, Deadly Reentry, Real Chute, Procedural Fairings, Kerbal Joint Reinforcement, ScanSat, and many more mods on an AMD Athlon Dual Core 4850e 2.5GHz machine with 2GB of memory and Windows Vista Business 32 bit. It's a Dell Optiplex 740 to be specific. FAR has next to no effect on my install's framerate or other performance. The Trajectories mod however results in lots of 1-2 second freezes. Go figure.

Ferram isn't doing computational fluid dynamics in FAR. It's not exactly taxing.

[smjjames]

What is cd value??

[regex]

What is cd value??

https://github.com/ferram4/Ferram-Aerospace-Research/wiki/Definition-of-Terms-and-Symbols

You can pretty much plug any term name into Wikipedia for a detailed definition. For instance:

Drag Coefficient

[Wanderfound]

What is cd value??

Coefficient of Drag.

[Axelord FTW]

FAR isn't hard.

It's just different.

You learn it the same as you learn stock aero.

It might actually be easier to get into (learning speed, not depth) if you already have some understanding of aerodynamics.

[BudgetHedgehog]

FAR is hard, but it's rewarding. Then it's easy. People complain about the ÃŽâ€V requirement being lower, but forget that ÃŽâ€V to LEO is about 9.5 km/s and about 7.8 of that is horizontal. LKO orbital velocity is 2.4 km/s so it makes sense that the total requirement is about 3.4km/s. You shouldn't need to spend half your ÃŽâ€V fighting through soup...

I love FAR, I really do. It makes KSP make sense to me.

[Panzerbeard]

I've played around with NEAR, haven't looked at FAR yet, but does anyone have a simple explanation of how the in-flight tools work? I can't find any guides or documentation for it. I'm pretty sure I understand the tools in the SPH/VAB, I just find the in-flight window a little unintuitive.