Stock Game not very fun without Delta-V & TWR readout

[LoSBoL]

14 minutes ago, GoSlash27 said:

Kobymaru,

 Perhaps you'd like to volunteer to explain that to all the people who complain when the software *they paid money for* doesn't work right?

 

Slippery slope fallacy...

But like with any vehicle... Your mileage may vary

[GoSlash27]

LoSBoL,

 

1 hour ago, LoSBoL said:

Slippery slope fallacy...

... he says in a thread where people are complaining because their software isn't perfect.

Yep, my mileage varies... I computed it at sea level (reflecting the real world). Perhaps I should try vacuum instead...

Edited March 24, 2018 by GoSlash27

[LoSBoL]

8 minutes ago, GoSlash27 said:

LoSBoL,

 

... he says in a thread where people are complaining because their software isn't perfect.

Yep, my mileage varies... I computed it at sea level (reflecting the real world). Perhaps I should try vacuum instead...

Tu quoque fallacy, you're on a roll...

[OHara]

2 hours ago, Kobymaru said:

The answer is: vacuum dV. It's perfectly correct in space and on/around most of the bodies, it's almost perfectly correct in the upper atmosphere (for second stages) and it's still a reasonably good estimate for first stages because even those don't  spend much time in the lower atmosphere.

That is the right answer.  
Earlier I suggested using  the higher thrust, between vacuum or sea-level atmospheric, so that air-breathers show non-zero.  But, KER solves this problem better by having air-breathers always use its 'atmospheric' option.   DMagic's Basic Delta-V, of course, has the best simple user interface for the options, including an easy way to turn off the display.

Stock KSP shows, in the VAB hover-text for each engine, two values for thrust, vacuum and sea-level on Kerbin.
The mods give us a way to get thrust on any celestial body, at any altitude, by evaluating the in-game atmospheric curves.  Figuring the thrust in the atmosphere is helpful, for figuring thrust-to-weight on Eve's mountains, for which the only in-game alternative is to experiment with sacrificial landers.  

[GoSlash27]

1 hour ago, LoSBoL said:

Tu quoque fallacy, you're on a roll...

Somebody is . Which fallacy title will be misapplied in your next response in lieu of an actual point? I'm eager to find out

 

[Pthigrivi]

6 hours ago, GoSlash27 said:

Another complication that I was just reminded of:

KER is incorrect every time it attempts to calculate the DV of a launch stage, even when it's the simplest possible launch stage.
 Atmospheric t/w will be correct, but neither atmospheric *nor* vacuum DV will be right, since the launch stage doesn't spend it's time purely in either condition. If it's a SSTO rocket, it's mean atmospheric density will be much lower than if it's a short burn SRB just to get things moving. KER has no way of knowing and any answer it gives will be incorrect.

 This gives rise to another problem: What is the "correct" DV of a stage in varying atmospheric density? The KER vacuum value? The "true" value, which is uncalculable? The closest estimate based on it's starting and ending atmosphere?

Best,
-Slashy

 

 

I dont think we have to worry this down so much. If you supply both the vacuum and sea level dV players will just have to guestimate where in between that stage will spend most of its time. It's actually quite usefull when switching out different engine combinations to see those numbers bump around. In fact, this is a key example of how dV readouts can save you time without taking away all of the suspense. The game isnt supplying you with wrong information, its giving you an upper and lower bound and its up to you to interpret them.

 

5 hours ago, AVaughan said:

It can't, for the reasons I mentioned a few posts ago.  

Another situation it can't properly calculate is an Apollo style mission, where it can't know when the lander will be detached, and hence when the service module will stop having to push that extra weight.

Im almost always docking and undocking things and this isnt really a problem. You just disconnect the modules in the VAB and check their individual dV against the task they're designed for. Obviously the player is still going to have to think and do some homework. We're just asking for some basic tools to speed up the design and analysis process, and thereby speed up players' progress through the game overall. 

Edited March 24, 2018 by Pthigrivi

[OHara]

5 hours ago, Cpt Kerbalkrunch said:

Part of this is because I despise autostrut and refuse to use it.

That brings up the counter-point of the thread, making sure players can easily and naturally avoid game-features that spoil their fun.

I happen to think several features of KSP defeat the purpose of the game, in the sense of short-cutting the fun part.
{auto-struts, instant-scanning for ore, crew that work for free, science from biomes at each KSC building}
Most are easy to ignore, but I needed the mod ScanSat to replace the stock exploration, and had to get used to the bought-slaves model for crew.

For the sake of new players, I would recommend a delta-V toggle-button be shown in the Engineers' Report.  Then the first time a player has the concept of how many m/s he wants at a particular stage of a mission, the calculation is there for him to enable.    I am guessing here that the players whose fun would be ruined by a numerical display of dV,  would not go into the Engineer's Report looking for such numbers. 

Having the toggle default to off keeps the initial staging presentation simpler.  Logically, the thrust and I_sp for each engine would be hidden unless delta-V is displayed, simplifying those displays as well.  

Edited March 24, 2018 by OHara

[GoSlash27]

1 hour ago, Pthigrivi said:

I dont think we have to worry this down so much. If you supply both the vacuum and sea level dV players will just have to guestimate where in between that stage will spend most of its time.

True. It would also tip players off that they're looking at estimates, not exact values.

 I just fielded a question along these lines from a player using KER. He had it set to display vacuum in the VAB (enough for orbit), but of course it displays ambient on the pad (not enough for orbit). He was wondering why his ship had both enough and not enough, and his problem wasn't the DV at all, but rather his piloting technique.

He probably wouldn't have been so confused if it showed both values in the VAB in the first place.

Best,
-Slashy

 

[GoSlash27]

1 hour ago, OHara said:

Logically, the thrust and I_sp for each engine would be hidden unless delta-V is displayed, simplifying those displays as well.

I was with you until this point.

 "Logically"? I can explain how one would calculate DV from available information. How would one compute the thrust and Isp of a mystery engine in KSP, particularly career?

 

[JeeF]

What is a bit disheartening about these "delta-V readings and TWR readings in stock game please" threads is that we never get any official reply from the developers.

It's not that I don't enjoy reading each player's personal opinion, but it would be great to hear from the developers WHY the frak they still haven't added this super important thing to the stock game yet, dammit! XD

[GoSlash27]

1 hour ago, JeeF said:

What is a bit disheartening about these "delta-V readings and TWR readings in stock game please" threads is that we never get any official reply from the developers.

I consider it enlightening.

Best,
-Slashy

[OHara]

33 minutes ago, GoSlash27 said:

[with Thrust and I_sp hidden when delta-V is hidden]  How would one compute the thrust and Isp of a mystery engine in KSP, particularly career?

One would not compute either, but rather find the answers experimentally.

Players who enjoy the game by taking risks would build up KSP-intuition about the various engines can do.

Players who build spread sheets would test each engine in turn, measuring thrust by testing engines with weights on the pad, and vacuum thrust with timed burns and maneuver nodes in orbit, and measuring fuel-flow with the in-game clock.  

Right now, the game abstracts away the experimental testing of parts, making the parts available with numerical specifications for thrust and Isp, but no in-game tools to use those numerical specifications.   Presenting numbers in-game that cannot naturally be used in-game is what seemed confusing to me, in the sense that I cannot see what mode of play the presented information is meant to encourage.  Computing delta-V from in-game information needs a calculator plus significant recording with pencil, or two abacuses (wet and dry masses) plus slide rule, or a spreadsheet.

My implicit assumption, I suppose, is that computing is not the fun part for anyone, but that experimenting is the fun part for most people.

Edited March 24, 2018 by OHara
and there is plenty of experimenting to be done in vessel design with KER handling dV calculations, experimenting that I find more fun with KER handling the routine calculations.

[GoSlash27]

1 hour ago, OHara said:

Players who build spread sheets would test each engine in turn, measuring thrust by testing engines with weights on the pad, and vacuum thrust with timed burns and maneuver nodes in orbit, and measuring fuel-flow with the in-game clock.  

What "weights", specifically? Are you talking about adding a test stand to record thrust and fuel tanks for us to supply fuel for timed burns? 'Cuz the "experimentation" you so casually suggest isn't feasible in- game. 

1 hour ago, OHara said:

My implicit assumption, I suppose, is that computing is not the fun part for anyone, but that experimenting is the fun part for most people.

I could see it *if* such experimentation were practical in- game, but it's not. As long as we're throwing out suggestions that the devs aren't reading and don't care about, how about a test stand in the R&D? After all, engines aren't tested by heaving cinderblocks and anvils in the real world. In fact... when you buy an engine from a 3rd party supplier, they tell you what the mass, thrust and Isp are.

 What they *do not* have in the real world, however, is a device that you can place your rocket on and magically deliciously tell you what it's DV is. In the real world, you have to compute that yourself... or design the stage to meet that requirement in the first place.

[klgraham1013]

4 minutes ago, GoSlash27 said:

What they *do not* have in the real world, however, is a device that you can place your rocket on and magically deliciously tell you what it's DV is. In the real world, you have to compute that yourself... or design the stage to meet that requirement in the first place.

What you do have in real life is hundreds of people working for the companies that make said rockets.  I am but one man on the lonely road to discovering his shmelta vees. 

Edited March 24, 2018 by klgraham1013

[GoSlash27]

1 hour ago, klgraham1013 said:

I am but one man on the lonely road to discovering his shmelta vees. 

Fair enough, which is why you should have that ability if you want it. My comment was directed at OHara, who suggests modifications to the game to make it more fun... for other people.

[JeeF]

Best of both words: add the option to the stock game so that you can turn ON or OFF in VAB/SPH a simple dV/TWR readout.

Those who want, can turn it ON. Those who doesn't, well... a psychiatrist is always an option.

[klgraham1013]

8 minutes ago, GoSlash27 said:

Fair enough, which is why you should have that ability if you want it. My comment was directed at OHara, who suggests modifications to the game to make it more fun... for other people.

Yeah.  I've said it before.  Everyone has fun differently.  Some people find it legitimately fun to do math problems.  I know someone like that in real life.  I enjoy solving a Rubik's cube while watching documentaries.  To assume everyone has fun the same as you (not you, the other guy) is shortsighted.

At least I haven't seen the fallacy of the fun vs realism sliding scale on this forum recently.

Edited March 24, 2018 by klgraham1013

[HebaruSan]

I've sometimes thought it would be nice to have a simple interactive form of the rocket equation in some kind of hovering non-modal popup in the VAB:

  +------------------------------------------------------------------+
  |                                                                  |
  |  ______ m/s = ____ s * 9.81 m/s/s * ln( _____ ton / _____ ton )  |
  |                                                                  |
  +------------------------------------------------------------------+

This would perform the (computationally involved) calculation step and leave the rest to the player. I would imagine each blank as a freely editable field, possibly with two more controls per field:

• A dropdown to pull in known values from the active craft (the wet/dry mass and ISP of the full craft or each stage might be available)
• A lock/unlock toggle to control which variables are inputs and which is the output, probably unlocked for the delta V and locked for the rest by default

So I might fill in and lock my ISP and masses to get the delta V of my rocket. Or I might fill in and lock the dry mass, ISP, and delta V I want, and unlock the wet mass to figure out how much fuel I need.

This would provide a clue to the brand new player regarding the relevant math without trying to cover every last detail, and it offers the same amount of help for the Apollo case as for simple staging. For the "no spoilers" crowd, the equation is just sitting there empty in the corner, for you to use or not use as you choose. And it allows SQUAD to claim the "garbage in, garbage out" caveat for any inaccuracies, since it's up to the player to plug in the right values for the "overly complex staging" everyone is so concerned about.

Edited March 24, 2018 by HebaruSan

[GoSlash27]

HebaruSan,
Cool concept! Heck, I'd even use it myself. It would be super- helpful outside of the VAB as well... even moreso than inside. I never need to see my ship's DV inside the VAB because I knew what it would be before I built it. But *outside*.... I often run into situations where I need to know the remaining DV. Deciding to take a satellite reposition contract, figuring out the "bingo" fuel for a landing, etc.

Best,
-Slashy

Edited March 24, 2018 by GoSlash27

[Pthigrivi]

Yeah I think everyone would agree a toggle or drop down is best. I dont even want it cluttering up my screen most of the time. Im also not averse to having it be a part of a VAB upgrade in career. I think its good for new players to feel out their launches for a while, get an intuitive sense of how much fuel they need, what the consequences are for being over or underpowered. Its later when they're transitioning into more ambitious missions that having that direct data feedback would help them make more efficient designs without spending huge amounts of time repeatedly guessing and testing, or even manually recalculating each time they switch out an engine. 

[Bill Phil]

3 hours ago, klgraham1013 said:

Yeah.  I've said it before.  Everyone has fun differently.  Some people find it legitimately fun to do math problems.  I know someone like that in real life.  I enjoy solving a Rubik's cube while watching documentaries.  To assume everyone has fun the same as you (not you, the other guy) is shortsighted.

At least I haven't seen the fallacy of the fun vs realism sliding scale on this forum recently.

I enjoy doing calculations. Even delta-v. But for KSP? It gets tedious. I'd love a delta-v readout. For VAB and in-flight. Others will have different preferences, inevitably. So, just like advanced tweakables, commnet, reentry heat, and more, it should be an option.

[OHara]

5 hours ago, GoSlash27 said:

Are you talking about adding a test stand to record thrust and fuel tanks for us to supply fuel for timed burns?

Well, don't take me too seriously, because as you say I am just brainstorming ways to preserve what other people describe as part of their fun.  Here I was imagining a player who wants nothing given to him that could otherwise be earned or discovered in-game.

Measuring sea-level thrust is (objectively, I dare say) more fun than the early-career "test engine by staging" tasks.  We can get starting and ending masses from the 'i' button on the Map View, and note the mission elapsed time between staging and when the craft just begins to lift off.   I was a bit excited to go back to the VAB and see how far off the measurements were.
fuel flow = (19040kg - 15580kg)/62s = 56kg/s
thrust = 15580kg × 9.81m/s² = 153kN
specific impulse  = 153kN / 56kg/s = 2730m/s
conventional Isp = 15580kg / 56kg/s = 278s

Measuring the vacuum values, however, was awkward because I had to get the tested engine above the atmosphere.  Full thrust would give too short a burn time to measure to precisely, so I set the thrust limiter to 10%, and tried to ignore the engine stats in that pop-up window.
fuel flow = (3120kg - 2390kg) / 35s = 5.4kg/s    at 10% throttle
thrust = (3120kg + 2930kg)/2 × 200m/s /35s = 17.3kN  at 10% throttle
specific impulse = 17.3kN / 5.4kg/s = 3200 m/s
conventional Isp = 3200m/s / g = 326s

So we can measure engine stats in-game within a few percent accuracy, and there is no need to have them displayed in the VAB.   People who don't want to see the numbers, though, seem to have no problem simply ignoring them.  

Edited March 25, 2018 by OHara

[OHara]

4 hours ago, HebaruSan said:

I've sometimes thought it would be nice to have a simple interactive form of the rocket equation in some kind of hovering non-modal popup in the VAB:
    [ . . . ]
This would perform the (computationally involved) calculation step and leave the rest to the player. I would imagine each blank as a freely editable field, possibly with two more controls per field:

• A dropdown to pull in known values from the active craft (the wet/dry mass and ISP of the full craft or each stage might be available)

There have been suggestions to make a momentary button on each stage in the VAB staging display, to show the dry-craft mass and center-of-mass when the button is pressed (reducing the frustration of forgetting to refill our tanks when we check the dry craft manually).   I can imagine that button populating your formula with the dry mass when pressed, and the wet mass when released.   That spares the player the most error-prone and tedious part.

Here, wet mass for a stage would be the mass after burning any fuel that engines activated in earlier stages can access, and after decoupling any parts that earlier stages decouple.  Dry mass would be after burning all fuel reachable by any engine activated by the current stage.

4 hours ago, HebaruSan said:

• A lock/unlock toggle to control which variables are inputs and which is the output, probably unlocked for the delta V and locked for the rest by default

Simpler, and maybe general enough, would be to compute delta-V whenever the other quantities are committed, but compute wet mass when delta-V is entered.

[LoSBoL]

12 hours ago, GoSlash27 said:

Somebody is . Which fallacy title will be misapplied in your next response in lieu of an actual point? I'm eager to find out

 

Well, that's another Tu Quoque fallacy, you're making it way to easy...

[Cpt Kerbalkrunch]

14 hours ago, HebaruSan said:

I've sometimes thought it would be nice to have a simple interactive form of the rocket equation in some kind of hovering non-modal popup in the VAB:

  +------------------------------------------------------------------+
  |                                                                  |
  |  ______ m/s = ____ s * 9.81 m/s/s * ln( _____ ton / _____ ton )  |
  |                                                                  |
  +------------------------------------------------------------------+

This would perform the (computationally involved) calculation step and leave the rest to the player. I would imagine each blank as a freely editable field, possibly with two more controls per field:

• A dropdown to pull in known values from the active craft (the wet/dry mass and ISP of the full craft or each stage might be available)
• A lock/unlock toggle to control which variables are inputs and which is the output, probably unlocked for the delta V and locked for the rest by default

So I might fill in and lock my ISP and masses to get the delta V of my rocket. Or I might fill in and lock the dry mass, ISP, and delta V I want, and unlock the wet mass to figure out how much fuel I need.

This would provide a clue to the brand new player regarding the relevant math without trying to cover every last detail, and it offers the same amount of help for the Apollo case as for simple staging. For the "no spoilers" crowd, the equation is just sitting there empty in the corner, for you to use or not use as you choose. And it allows SQUAD to claim the "garbage in, garbage out" caveat for any inaccuracies, since it's up to the player to plug in the right values for the "overly complex staging" everyone is so concerned about.

I've seen some pretty good suggestions on here, but this one might be my favorite. It might even get those of us who prefer trial and error to learn some math. I'm diggin' it. So when's your mod comin' out?