[WIP][1.8.1, 1.9.1, 1.10.1, 1.11.0–2, 1.12.2–5] Principia—version ‎‎Kronecker, released 2024-11-01—n-Body and Extended Body Gravitation

[eggrobin]

4 hours ago, Teilnehmer said:

I’m trying now to add an option to make the mod’s UI more compact.

This is a good idea. Detailed reply in the pull request, let’s keep the discussion in one place.

[DeOriginale69]

14 hours ago, Teilnehmer said:

I believe,  it could be as tiny as in this sketch:

(with the mode descriptions in tooltips).

You could just keep it on the screen not bothering to hide it every now and then.

That is a wonderful idea. Very simple but easy to understand icons for the ploting frames too. Nice sketch-up!

[Zeiss Ikon]

Okay, I'll freely admit I haven't read through 42 pages of this thread, but...

I'm a new user of Principia, running KSP on Ubuntu MATE 16.04.5 LTS 64-bit, using the 64-bit game, and it seems as if the installation procedure is pretty simple: I downloaded the 1.3.1 Ubuntu binary from the Google Drive link provided all the way back up at the top of the thread, extracted the contents and put the Principia folder inside the GameData folder in my chosen (new, RSS/RO, 1.3.1) KSP install.  Now, every time I try to load the game (after waiting through installing 33,514 patches -- there may yet be a few "recommended" or "suggested" mods I need to add), I get this error:

The.  File.  Is. There.

I moved the entire installation to my "internal" folder (my KSP installs and other long term storage generally live on a sym-linked folder, which has a space in its delinked path; I thought the space might be causing the problem), with no change.  This error occurs only when I launch from the desktop launcher I've been using for KSP since I installed 16.04 MATE almost four months ago; if I launch from a command line (at least if the current directory is the one the game is in; haven't tried it from a random directory folder, because typing long paths isn't fun) there's no error message (which I presume means the mod is working -- it's not quick and easy to verify n-body orbits in a newly installed game).

I have to presume this is because something in Principia isn't correctly detecting or applying the game's directory setting, or something in Ubuntu 16.04 or the MATE DTE is failing to set an environment variable Principia expects to find.

I'm not anything resembling an up-to-date programmer, nor even a Linux guru -- I get by on Linux, and if I have a book in front of me, I can write simple code in ANSI C.  If you want, I can try to wade through the bug reporting process you use, but it might take weeks before I have the time, which might delay someone being able to find and fix what's probably a fairly basic issue.

[scimas]

4 hours ago, Zeiss Ikon said:

~snip~

https://github.com/mockingbirdnest/Principia/wiki/Installing,-reporting-bugs,-and-frequently-asked-questions

Check the linux section.

The working directory needs to be the KSP directory for principia to run on linux, apparently.

On windows, there is an option in a shortcut's properties that determines in which directory an executable is opened. See if something similar is available to you if having the shortcut is important.

[Zeiss Ikon]

5 hours ago, scimas said:

https://github.com/mockingbirdnest/Principia/wiki/Installing,-reporting-bugs,-and-frequently-asked-questions

Check the linux section.

The working directory needs to be the KSP directory for principia to run on linux, apparently.

On windows, there is an option in a shortcut's properties that determines in which directory an executable is opened. See if something similar is available to you if having the shortcut is important.

I'm certain this is the problem; unfortunately, a desktop launcher in the MATE environment doesn't have an option to change the working directory, and compound commands ("cd something-or-other && run KSP") don't work in launchers, either.  I guess I'll have to make a short script to launch the convenient way.

[Zeiss Ikon]

Okay, I got the working directory problem straightened out -- in case anyone needs it, for Ubuntu MATE 16.04, the launchers don't support explicitly entering the working directory, but you can edit the .desktop file they produce with a text editor and add a key "Path=/home/username/KSPfolder" as appropriate.  Location in the file doesn't seem very important; I put it right before the Exec= key.

Unfortunately, after having to actually learn something I found I still couldn't play the game I wanted to play; apparently, RP-0 doesn't yet and may never support 1.3.1 -- so my options are to either build RP-1 from source (on GitHub), which I don't know how to do, or to run my RO/RSS/Principia game on 1.2.2.  Except now I'm finding there doesn't seem to be a binary (Ubuntu 64-bit) download available for any but the most current version of Principia, which supports only 1.3.1 and 1.4.3 (1.2.2 support was dropped, ironically, because RO now supports 1.3.1 -- which it does, except you can't run with a sensible tech tree unless you install RP-1; see above).

Am I missing something?  Is there in fact a binary download available for Cramer, Ubuntu 64-bit, KSP 1.2.2 version (and if so, why isn't it linked from the start of this thread)?

Edited June 3, 2018 by Zeiss Ikon

[scimas]

On 5/15/2018 at 11:52 AM, pleroy said:

Cramer for 1.2.2 is at https://goo.gl/XgRdRP.  We won't be looking into bugs or otherwise supporting Principia versions that target 1.2.2, though.

@Zeiss Ikon As far as I know, simply cloning the dev branch of RP-0 and using the GameData folder works in 1.3.1. Well, it works at least in windows, I have a working installation.

[pleroy]

20 hours ago, Zeiss Ikon said:

Am I missing something?  Is there in fact a binary download available for Cramer, Ubuntu 64-bit, KSP 1.2.2 version (and if so, why isn't it linked from the start of this thread)?

Thanks to @scimas for the reply.

Public service announcement: the links to the releases are in the README.md file on GitHub.  By looking at the history of this file, it's easy to find previous versions of the mod.

[Zeiss Ikon]

5 hours ago, scimas said:

@Zeiss Ikon As far as I know, simply cloning the dev branch of RP-0 and using the GameData folder works in 1.3.1. Well, it works at least in windows, I have a working installation.

Thanks, but can you translate that into non-dev for me, @scimas?  I'm not a developer, and though I've done a little coding (off and on, mostly off, since 1975), I haven't any idea how to either "clone the dev branch"  or build the program portion from source into a usable Ubuntu library.  Under Ubuntu, my program "building" experience pretty much ends with invoking gcc to get a stand-alone executable of a simple program (and I haven't done that in 4-5 years, I'd have to refresh myself on the syntax).  I recognize a makefile (because it's generally called that), but I don't know what to do with it.

Thanks, @pleroy -- I'm used to README files containing a change log and basic instructions, so it didn't occur to me to look in the current README for the link to an old version of the mod.  I'm still working out whether it would be easier to try to make RP-0 work in 1.3.1 or put up with 1.2.2 and pretty completely unsupported mods.  I'd rather use 1.3.1; it's quite a bit closer to the current 1.4.3 that I run in my (nearly) unmodded career, but RP-0 or RP-1 is one of my core desiderata for this setup -- a KSP that parallels the real history of spaceflight in the real Solar System with real gravity.

[Zeiss Ikon]

Okay, I think I may not need Cramer.

Just installed the freshly downloaded Dev Branch RP-0 -- and I now get RO/RP-0 flight shots instead of the usual KSP loading images, and have the correct tech tree (man, that thing is a spiderweb, isn't it?).

Haven't tried to reinstall Remote Tech yet, but I found a significant problem: the "Starter Parts" node has a note saying "These are the parts you start with after accepting the 'Unlock Parts' Contract."  And there are the Procedural Tanks, Procedural Nose Cone, Aerobee, A-4 and RD-100 engines, and a bunch of aero parts, girders, and umbilical towers.  Except that there is no "Unlock Parts" contract available in Mission Control -- in fact, there are no contracts of any sort.  I should probably take this to the RP-0 thread, since it looks like I'm going to be able to play the 1.3.1 (if I can get the contracts straightened out).  Just installed Contract Configurator, reloading the game now.

[Zeiss Ikon]

And First Launch contract fulfilled -- launched a "Captured V-2 (A-4)" to 197 km, peaking above 1500 m/s, and got something like 14 "world's first" awards (and missed Grand Bahama by enough not to start a war with the UK).  Now to fill in stuff like Kerbal Construction Time, Test Flight, and Remote Tech with the correct DLL.

Edited June 5, 2018 by Zeiss Ikon

[Xurkitree]

While I love the concept, I don't think my computer can handle 64 bit and this well...

Randome question though (hypothetical) - If we were to time warp with principia and rss to millions of years in the future, would it be possible for Phobos to crash into Mars? Alternatively, would the Moon go away?

 

Nobody can warp that long, even with mods, but is it possible? what would happen then?

[scimas]

25 minutes ago, Xurkitree said:

While I love the concept, I don't think my computer can handle 64 bit and this well...

I'm not a tech expert myself, but isn't almost every PC since at least about 2010 a 64 bit PC?

19 hours ago, Zeiss Ikon said:

Thanks, but can you translate that into non-dev for me

I'm not a developer either, but seems like you figured it out

[Zeiss Ikon]

4 hours ago, scimas said:

I'm not a developer either, but seems like you figured it out

I got a little more detail on how to "clone the branch" on another sub-forum where I'd mentioned I was trying to get RO/RP-0 running.  Right now, I'm searching for Test Flight (which isn't on CKAN, seemingly) and once I know that and Remote Tech are working correctly, I'll install Kerbal Construction Time and be ready to play.

[Zeiss Ikon]

5 hours ago, Xurkitree said:

Randome question though (hypothetical) - If we were to time warp with principia and rss to millions of years in the future, would it be possible for Phobos to crash into Mars? Alternatively, would the Moon go away?

I'm pretty sure even Principia doesn't model the processes that are bringing Phobos down and pushing Luna out.  Those are both due to tidal friction, which depends on (in the case of Phobos, extremely small) effects from tidal bulges -- the tidal bulge Luna raises in Earth moves ahead (because Earth turns faster than the Moon orbits), and drags the Moon along, which pushes it out into a slower orbit.  In a hundred million years a Lunar month will be something like forty days.  In the case of Phobos, the effect is much smaller, because it has far less effect on Mars than Luna does on Earth -- but Mars rotates slower than Phobos orbits, so the drag from the tidal bulge pulls Phobos back and will eventually decay its orbit enough to enter the atmosphere and cause a catastrophe.

Principia, however, though it does treat planets as extended bodies (rather than point masses), as far as I'm aware still models them as rigid.  I'm pretty sure it doesn't even take the Earth's (or Jupiters, or Saturn's) oblateness into account -- and oblateness is a much stronger effect than tidal bulges.  Masscons on the Moon are probably not modeled, either -- even though they're why there are no long-term stable low orbits around the Moon except polar ones.

[eggrobin]

42 minutes ago, Zeiss Ikon said:

Principia, however, though it does treat planets as extended bodies (rather than point masses), as far as I'm aware still models them as rigid.

Indeed. We have no plan to model tides in the foreseeable future.

Quote

I'm pretty sure it doesn't even take the Earth's (or Jupiters, or Saturn's) oblateness into account -- and oblateness is a much stronger effect than tidal bulges.

It does model oblateness, that's the "extended-body" part in the title (they are modeled as oblate bodies rather than point masses, and that is the extent of the "extended" for now).

Quote

Masscons on the Moon are probably not modeled

Not yet at least. For high-order gravity models, we would need to think about a practical way to limit the range, as we don't want to have to compute high-order lunar gravitation all the way to Jupiter.

Note that this is relevant even for the orbit of Phobos, as Mars has a pretty misshapen gravitational field.

[Zeiss Ikon]

Not a real programmer/developer nor a mathematician, but it seems like the fine details of masscons and the like would pretty much be lost by the time you're some distance away.  For the Moon, if you're as far away as the Earth, perturbations by other bodies are likely to overwhelm the effects of oblateness, masscons, and internal non-uniformities (most bodies the size of the Moon have density discontinuities due to differentiation; the Moon is odd in that regard, probably related to its formation from the Theia collision).  For Mars, the elephant in the room is Jupiter -- when Jupiter's perturbation effects are greater than those of Mars's masscons, there's no point modeling the masscons.  I'll go out on a limb and say that by the time the body subtends less than some fraction of a degree (final value likely reached by cut-and-try methods, but probably somewhere between 15 arcminutes and a full degree) the effects of masscons are below computation error.

[eggrobin]

For the new moon (lunation number 228), the new release (Dedekind) is out.

This release fixes a memory leak which could lead to increases in memory usage to the tune of 1 GiB / min when using the flight plan.
Further, we are releasing a mini-mod that turns @GregroxMun's SLIPPIST-1 into the real TRAPPIST-1 system; the 7-planet resonant chain of that system makes it interesting from the perspective of n-body gravitation. The configuration is computed by transit-timing variation based on the transit timings from the recently-published paper The nature of the TRAPPIST-1 exoplanets by Grimm et al.

See the change log for more details.

We support two versions of KSP: downloads are available for 1.4.3 and 1.3.1. Make sure you download the right one (if you don't, the game will crash on load).

[drtedastro]

Thanks again...

really great work.

cheers.

[Windspren]

Does anyone have a patch for a 6.4x Kerbol system that fixes the Jool system?

Edited June 16, 2018 by Windspren

[hypervelocity]

On 6/13/2018 at 2:36 PM, eggrobin said:

For the new moon (lunation number 228), the new release (Dedekind) is out.

This release fixes a memory leak which could lead to increases in memory usage to the tune of 1 GiB / min when using the flight plan.
Further, we are releasing a mini-mod that turns @GregroxMun's SLIPPIST-1 into the real TRAPPIST-1 system; the 7-planet resonant chain of that system makes it interesting from the perspective of n-body gravitation. The configuration is computed by transit-timing variation based on the transit timings from the recently-published paper The nature of the TRAPPIST-1 exoplanets by Grimm et al.

See the change log for more details.

We support two versions of KSP: downloads are available for 1.4.3 and 1.3.1. Make sure you download the right one (if you don't, the game will crash on load).

@eggrobin - I have never used a Planet Pack before with RSS - in regards of the mini-mod for TRAPPIST-1, what are the installation instructions? Should I install GregroxMun's mod and everything will work automagically?

Thanks in advance, and thanks for the new release and all the work put into this mod, it is absolutely fantastic, total game-changer!

[pleroy]

1 hour ago, hypervelocity said:

@eggrobin - I have never used a Planet Pack before with RSS - in regards of the mini-mod for TRAPPIST-1, what are the installation instructions? Should I install GregroxMun's mod and everything will work automagically?

Use the FAQs, Luke!  The FAQs have instructions for installing "Trappist-1 for Principia".

Two caveats, though:

1. Our mini-mod is on top of GregroxMun's mod, not on top of RSS, so it's incompatible with RSS (you cannot be in two solar systems at the same time, right?).
2. If you are using 1.4.3 there's a glitch and it will fail to load because of an incompatibility with Kopernicus.  Give us a few days to update the .zip file.

[hypervelocity]

@pleroy gotcha!! thanks!! sorry for the FAQ's, I usually use them!

[王小谦同学]

@pleroyMy friend and me is currently working on simulating Voyager 2's orbit in RSS+RO+Principia+a bunch of other spacecraft mod but it seems to be crashing near Saturn when using time warp, the game version is pre1.3.1, principia version is the one just released, idk if there is any solutions. My friend have 16g RAM and I have 64g RAM, but I am out, and can't get anywhere close to my computer. Even we tried to delete all mods that is not used, it's still crashing when have a warpspeed higher than 6x, if not delete them, even using a 2x warp will crash the game.

[Agustin]

1 hour ago, 王小谦同学 said:

 

you'll probably need to upload the LOG file through an external link if you want the developers to help you. Search where it is located on your system in the How to get suppot thread you can google.