Why isn't delta-v exposed in Stock (yet)?

[mattinoz]

20 minutes ago, Gargamel said:

I hope they would have to.  I think if there is an in game DV readout, it should be as simple as possible.   At best showing the DV for each stage.  Of course this would have to be unlocked or researched in some fashion, requiring the player to still try to figure out what the math themselves.   But there comes a point when you have learned something, that it becomes cumbersome to do it repeatedly.  That point differs between people, (ahem slashy ).   Having the subway map included in the game somehow might be nice, but tabbing between windows is probably easiest. 

Subway map is only for ideal transfers which still leaves lot of room for error if you don't understand.

[Bill Phil]

Actually, I've found myself just... getting a feel for it. It's really weird to me, but every time I've made a rocket recently it works pretty well and the payload on it makes orbit. Usually only barely. Sometimes with extra propellant, but margin is always good.

Not to say that I wouldn't mind a Delta-V display. Or an apoapsis/periapsis display out of the map. This stuff could be a toggle in options, like advanced tweakables. That way the players who want it get it, and the new players aren't forced to deal with more numbers.

Edited March 12, 2018 by Bill Phil

[sevenperforce]

13 minutes ago, Bill Phil said:

Actually, I've found myself just... getting a feel for it. It's really weird to me, but every time I've made a rocket recently it works pretty well and the payload on it makes orbit. Usually only barely. Sometimes with extra propellant, but margin is always good.

This is the case for me as well. I know generally how much thrust and how much fuel I need to make orbit with a given payload.

[Marschig]

There is no reason for the absence of dV and TWR. This causes you to frequently switch to Excel. I installed KER when I was tired of pressing Alt-Tab.

[_stilgar_]

Delta-V readout would be nice, but... when I tried KER, all the data it provided, it almost made the game too easy  

I can calculate the delta-v by hand, but I wish the game would just tell me the dry weight of my rocket. Right now, I have to write down the full weight, drain all the tanks, write down empty weight, calculate delta-v, refill the tanks... and then, during Mun landing, notice that the lander has no fuel because I forgot to refill that one tank... 

[Guest]

Hear hear. 

Nobody cares how many kilograms of fuel / oxidant they have left. They care about how many m/s they have left. It's a simple equation. Not having the information displayed in stock instead of or in addition to the regular fuel gauges is just boneheaded, especially as dV is happily used everywhere else.

[_stilgar_]

3 minutes ago, Brikoleur said:

Nobody cares how many kilograms of fuel / oxidant they have left. They care about how many m/s they have left.

Even worse, the "how much fuel I have" is misleading. You see that you've used half of the fuel, so maybe it's time to go back home, but then you have to remember that you still got most of your dV. 

At least they could put a logarithmic scale on the fuel left gauge. 

[Guest]

10 hours ago, LukasKerman said:

I think that is exactly the realm of mods especially since the readout is so unreliable when you think about the endless possibilties you can build a rocket.

The dV readout is not unreliable at all. It's a simple equation. All you need to know is engine ISP, payload mass, and propellant mass. This is much more straightforward than, say, patched conics, and the game has indicators for those.

Any "unreliability" you might get comes from staging and fuel feed settings, and they're perfectly straightforward too: start a fuel feed, and the propellant in the tank you're feeding from gets switched from payload mass to propellant mass; lock a tank and it goes the other way.

[_stilgar_]

1 minute ago, Brikoleur said:

It's a simple equation.

It's simple when you have simple rocket. Add boosters with different ISP, different burn time and staged halfway through and it stops being simple. 

[MR L A]

11 hours ago, dlrk said:

The fact that Squad has refused to implement the functionality of some pretty critical mods, like a Delta-V read out, or atmospheric/rotation-sensitive trajectory display, or realistic aerodynamics, or procedural parts is pretty mind-boggling.

DV read out is the one on that list I'd consider anything like essential. 

Realistic aerodynamics just takes ages to code, uses up valuable cpu time (results in lower part count), frustrates a lot of players, and only really allows for things like ground effects - as cool as that is, I'd sooner they leave aero alone and fix/build other things.

Trajectory... I've only played one playthrough with this. Useful for other planet missions but even the modded version isn't all that accurate and I can certainly live without it.

NEVER used procedural parts. 

[Guest]

11 minutes ago, _stilgar_ said:

It's simple when you have simple rocket. Add boosters with different ISP, different burn time and staged halfway through and it stops being simple. 

Maybe a little less simple, but still not that complicated. With an engine mix of different ISPs you need to know the propellant flow rate for each engine and calculate a weighted average ISP,  then use that. With boosters that have a separate fuel supply the math is a bit more complicated as you have to account for the change in mass of the main craft they're boosting. If the craft is at rest, you'd assume that everything is firing at full throttle; if it's flying, you plug in the fuel flow at the current setting.

If you want to account for the effect of atmosphere, you need to adjust the ISP on the fly.

All this does make the math a bit more complex, but there's no unreliability or ambiguity about it.

[Laie]

This topic isn't new... the last time I recall where someone from Squad bothered to step in and give a reply, it was that they were afraid of sometimes getting it wrong.

Keep in mind that vessels are not always strightforward 1st, 2nd, nth stage as with a Saturn-V. KSP gives the player a lot of freedom to come up with the most outrageous contraptions, and even more freedom in how to use them.

• A simple issue is "stage 2 is lit, next item is to jettison the fairings" -- will they be jettisoned ASAP, or only after stage2 is done, or (quite likely) sometime in-between?
• Slightly more complicated, you have Skipper flanked by two SRBs and throttle down the skipper to 50% shortly after takeoff.
• And then there's the wholly weird vessel with crossfeed and fuel lines where the dV algorithm just cannot follow. I don't have an example handy, but the peeps at Squad assumed that it wouldn't take long for some player to come up with a vessel that overtaxes their dV thingy.

The reasoning was that a mod can afford to be wrong some of the time, while the expectation for a a stock dV meter would be to get it right every.single.time, no matter what the player throws at it, under penalty of causing a major excrementsstorm.

Edited March 12, 2018 by Laie
oh the profanity filter, ain't it cute?

[severedsolo]

I've mentioned this before, but at some point someone at squad has at least tried to put a deltav readout in. In the api there is a method called GetDeltaV(Vessel), but it always returns zero.

[Guest]

Because SQUAD

 

[mattinoz]

25 minutes ago, Laie said:

This topic isn't new... the last time I recall where someone from Squad bothered to step in and give a reply, it was that they were afraid of sometimes getting it wrong.

Keep in mind that vessels are not always strightforward 1st, 2nd, nth stage as with a Saturn-V. KSP gives the player a lot of freedom to come up with the most outrageous contraptions, and even more freedom in how to use them.

• A simple issue is "stage 2 is lit, next item is to jettison the fairings" -- will they be jettisoned ASAP, or only after stage2 is done, or (quite likely) sometime in-between?
• Slightly more complicated, you have Skipper flanked by two SRBs and throttle down the skipper to 50% shortly after takeoff.
• And then there's the wholly weird vessel with crossfeed and fuel lines where the dV algorithm just cannot follow. I don't have an example handy, but the peeps at Squad assumed that it wouldn't take long for some player to come up with a vessel that overtaxes their dV thingy.

The reasoning was that a mod can afford to be wrong some of the time, while the expectation for a a stock dV meter would be to get it right every.single.time, no matter what the player throws at it, under penalty of causing a major excrementsstorm.

 

All the more reason to make the value stock reports indicative and rounded as guide . Keep it simple and if it has quirks then thats Kerbal. Leave acuracy for mods but give stock the tools it needs to draw players in. 

[katateochi]

9 hours ago, GoSlash27 said:

 I think that's *exactly* what Squad wanted. I think KSP was intended to make the player a better rocket scientist. Becoming a better rocket scientist includes learning the math.

Best,
-Slashy

I agree, KSP has forced me to learn so much, and that's been so satisfying! If the game just gave you the info then you don't need to learn. (I actually felt a little sad when maneuver nodes got added, 'cos I felt it removed what was for me one of the greatest ahha moments about how orbits interact and made rendezvous rather simple, but then again, with them you can be so much more efficient).

It's also because the game didn't tell me anything about dV that I met all of you folk! After a couple weeks of trail and mostly error and only making it to Mun on pure luck, I thought there must be a better way and went looking and found this awesome community of helpful (and frighteningly clever) folk. And that's when KSP really started for me.
A game that's insanely fun and yet makes people go out and learn stuff and connect up with other like minded folk is an awesome thing. It's also spawned a whole ecosystem of resources, not just mods, but online calculators, dV charts and shared spreadsheets.  

 

 

[GoSlash27]

6 hours ago, Gargamel said:

But there comes a point when you have learned something, that it becomes cumbersome to do it repeatedly.  That point differs between people, (ahem slashy ). 

 It's not the least bit cumbersome for me, since I've built a spreadsheet. I just enter what I need my stage to do, and it tells me what I need to build to make it happen. Which engine to use, how many fuel tanks, percentage to fill the last tank, and how much it'll cost. It's actually *less* cumbersome than mucking about in the VAB with MechJeb trying to T&E a working stage with no idea if there's a lighter or cheaper option available.

 Bonus: I can do stage design and mission planning when I'm not playing KSP and I never have to worry about updates breaking my game.

Same deal with my orbital mech and mission planning spreadsheet. It gives a lot more info than the subway map and allows me to plan pretty much any maneuver.

Best,
-Slashy

[Hans Dorn]

2 hours ago, _stilgar_ said:

You see that you've used half of the fuel, so maybe it's time to go back home

That's how I used to build my rockets.

Works like a charm

[klgraham1013]

8 hours ago, OHara said:

One of Dmagic's mods does a nice job of presenting delta-V, computed using KER's code, in a simple way.  

 

I agree.  I think this is a great integration into the stock UI.

[bonyetty]

1 hour ago, katateochi said:

I agree, KSP has forced me to learn so much, and that's been so satisfying! If the game just gave you the info then you don't need to learn. (I actually felt a little sad when maneuver nodes got added, 'cos I felt it removed what was for me one of the greatest ahha moments about how orbits interact and made rendezvous rather simple, but then again, with them you can be so much more efficient).

It's also because the game didn't tell me anything about dV that I met all of you folk! After a couple weeks of trail and mostly error and only making it to Mun on pure luck, I thought there must be a better way and went looking and found this awesome community of helpful (and frighteningly clever) folk. And that's when KSP really started for me.
A game that's insanely fun and yet makes people go out and learn stuff and connect up with other like minded folk is an awesome thing. It's also spawned a whole ecosystem of resources, not just mods, but online calculators, dV charts and shared spreadsheets.  

 

 

Spot on description of my Kerbal experience. I concur. Also with Slashy. And while on topic ish.

Thanks Harvester for keeping Delta V out of Kerbal.

[severedsolo]

I mean I get the points made about doing it yourself, and on pc this is fine, but what about console users?

Realistically speaking, it's going to be difficult to do that maths on the fly using a console, unless you have a tablet to hand with Google sheets or whatever open. That's hardly good design.

personally, I don't really care, I just use KER, but I do think they should at least consider it for consoles

[sevenperforce]

4 hours ago, _stilgar_ said:

Delta-V readout would be nice, but... when I tried KER, all the data it provided, it almost made the game too easy  

I can calculate the delta-v by hand, but I wish the game would just tell me the dry weight of my rocket. Right now, I have to write down the full weight, drain all the tanks, write down empty weight, calculate delta-v, refill the tanks... and then, during Mun landing, notice that the lander has no fuel because I forgot to refill that one tank... 

Happens. Every. Time.

Though this is, in large part, why I play with Tweakscale whenever I can. I need to leave the upper stages fueled to calculate lower-stage dV, so knowing the total dry weight of my rocket wouldn't help. Only needing to defuel and refuel a single tank for each stage makes it easier.

12 minutes ago, severedsolo said:

I mean I get the points made about doing it yourself, and on pc this is fine, but what about console users?

Realistically speaking, it's going to be difficult to do that maths on the fly using a console, unless you have a tablet to hand with Google sheets or whatever open. That's hardly good design.

personally, I don't really care, I just use KER, but I do think they should at least consider it for consoles

The console can still pause, right?

I usually keep quantumg's dV calculator open on my phone.

3 hours ago, Laie said:

This topic isn't new... the last time I recall where someone from Squad bothered to step in and give a reply, it was that they were afraid of sometimes getting it wrong.

Keep in mind that vessels are not always strightforward 1st, 2nd, nth stage as with a Saturn-V. KSP gives the player a lot of freedom to come up with the most outrageous contraptions, and even more freedom in how to use them.

• A simple issue is "stage 2 is lit, next item is to jettison the fairings" -- will they be jettisoned ASAP, or only after stage2 is done, or (quite likely) sometime in-between?
• Slightly more complicated, you have Skipper flanked by two SRBs and throttle down the skipper to 50% shortly after takeoff.
• And then there's the wholly weird vessel with crossfeed and fuel lines where the dV algorithm just cannot follow. I don't have an example handy, but the peeps at Squad assumed that it wouldn't take long for some player to come up with a vessel that overtaxes their dV thingy.

The reasoning was that a mod can afford to be wrong some of the time, while the expectation for a a stock dV meter would be to get it right every.single.time, no matter what the player throws at it, under penalty of causing a major excrementsstorm.

Right, this is absolutely correct.

What if you have a single stage that has two different propellant types in parallel? The most efficient thing to do is burn your lower-ISP propellant up first, of course. But if you designed your stage with two different propellant types, you probably had a reason for doing so, one which involved using specific propellants at specific times, which will make your stage's propellant usage (and thus its total dV) lower than the most efficient case. The stock dV meter has no knowledge of when or how you will do this, of course. If it aims for the worst-case scenario, it'll be wildly wrong; if it aims for the best-case scenario, it'll be wildly wrong. Either way, it doesn't work.

Or what if you have airbreathing engines and nukes on the same stage? 

[Warzouz]

15 hours ago, dlrk said:

The fact that Squad has refused to implement the functionality of some pretty critical mods, like a Delta-V read out, or atmospheric/rotation-sensitive trajectory display, or realistic aerodynamics, or procedural parts is pretty mind-boggling.

Agreed. I can' fathom that...

Without dV reading, you can use a prebuilt rocket and go to the Mun. But without it, you can't really build a mission outside of Kerbin SOI. You don't even have phase angles, delta-V maps.

"Trial and error"  : when you build a ship for Jool, you take a long time to fly it there. Figuring after hours of game that your design is not good because you hadn't display of any kind, turn into rage quit.

Without mods, I sure that I would have dumped KSP for a long long time...

- Try to play a multi mission career without KAC...
- Try to build a mission to Jool without KER
- Try to go to any other planet without some kind of transfer window tool (external or mod)
- Try to play a long time career without some search/hide ship feature mod (like haystack)
- Try to land (as a beginner) without altitude display or time to impact.

It's like driving a car without tires or with an opaque wind shield...

 

[_stilgar_]

4 minutes ago, Warzouz said:

- Try to land (as a beginner) without altitude display or time to impact.

The game has both of those, but for some reason, in IVA view only. 

[McFarnsworth]

While I agree a dV and TWR readout is pretty much mandatory, I can understand why Squad won't put it in stock. Most of my craft cause Mechjeb and KER to give me wildly inaccurate numbers. Fine for a mod, and I know why it happens and can work around it, but that wouldn't be an option in a stock game.

It would be a broken feature at best, and unless you severely limit construction options there's no real way to make it work reliably.