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Everything posted by eggrobin

  1. For the new moon (lunation number 258), the new release (Гельфанд) is out. Performance of operations based on iteration over trajectories has been improved thanks to a contribution from @rnlahaye. See the change log for more details. For the convenience of our Chinese users, the binaries can be downloaded either from Google Drive or from 腾讯微云.
  2. [Note: this was clarified over Discord; answering the questions asked here for posterity] Your system is either unstable, or doing things too quickly for the default integration settings (« unstable » is just a special case of that, where close encounters happen too quickly; Principia doesn’t (yet) care about orbits nor whether things remain on them). US2 tends to be an unreliable predictor of what happens to a solar system with Principia (probably because of different conventions for the representation of the initial state, possibly of its choice of numerical methods and timesteps ).
  3. For the new moon (lunation number 257), the new release (Gauss) is out. A bug that would occasionally lead to crashes when parts exploded has been fixed (#2716). See the change log for more details. For the convenience of our Chinese users, the binaries can be downloaded either from Google Drive or from 腾讯微云.
  4. For the new moon (lunation number 256), the new release (Gateaux) is out. Support for 1.10.1 has been added. Note that the behaviour of Principia in the presence of comets is hard to test; users who encounter problems when comets are present are invited to report bugs. See the change log for more details. For the convenience of our Chinese users, the binaries can be downloaded either from Google Drive or from 腾讯微云.
  5. If we look for a gravity model for Eeloo, this means Eeloo is present. If Eeloo is present with RSS, this means RSS is improperly installed.
  6. For the new moon (lunation number 255), the new release (Galois) is out. It is now possible to insert and delete manœuvres in the flight plan; in particular, this makes it possible to insert correction manœuvres after rebasing. Manœuvres can be collapsed and expanded, making it easier to manage flight plans with many manœuvres. A bug involving incorrect thrust when planning RCS manœuvres was fixed. Thanks to @Butcher for contributing this fix. See the change log for more details. For the convenience of our Chinese users, the binaries can be downloaded either from Goo
  7. The stock tidal locking flag never really works in the presence of Principia, and leads to aberrant spin and de-spin; Principia thus always disables it. It should be noted that, in a non-Keplerian world, finding the correct rotation period for tidal locking is tricky. As you have seen in the orbit analyser, satellites have three different orbital periods, none of which are equal to the osculating period (the period of the stock Kepler orbit at a given instant), and the same holds for a celestial body. Since we do not model pressions of the axes at this time (the rotation axis is fixe
  8. For the new moon (lunation number 254), the new release (Gallai) is out. As previously announced, this release dose not support KSP 1.7.3 and earlier. A rebase button has been added to the flight plan, to take changes to the actual trajectory into account without having to recreate the flight plan. Altitude-related information has been added to the orbit analyser. A number of bugs have been addressed: EVA collision leading to absurd movement, EVA parachutes being broken, vessels disintegrating at absurd speeds, vessels deforming when coming out of warp. See the chan
  9. @pleroy and I are the authors. This is not our job, no managers are involved (except of course for @sarbian’s ModuleManager). As for your remark, there is a new Principia release every new moon; whether the mod needs to be updated or not is entirely irrelevant to that schedule. I think with that needs you are alluding to 1.10 support; even when things go smoothly, it often takes several Principia releases before we support a new KSP version, just to check that everything is fine with the new version. Here things may not be completely smooth, as, depending on how they were imp
  10. There is a mod that gives you that: Principia. Evidently you want something else. It is not clear to me whether you mean complexity for the player or complexity for the implementer. If you care about implementation complexity (but why would you? it is our burden, not the player’s), Dealing only in three-body mechanics would make things strictly more complicated: you would end up with a maze of special cases and nasty transitions between situations where you choose two given bodies, and you would still have to deal with the full complexity of stable numerical integr
  11. While the cost of prolonging the ephemeris is quadratic in the number of massive bodies (whereas computing the trajectory of a vessel is linear in that number) the timescales are very different (at least in the worst case, and since it is not possible to have variable step size and symplecticity, the chosen step size must accommodate the worst case); this is a case where the constant factor matters more than the asymptotic behaviour (the number of massive bodies remains fairly small, even with RSS). As @scimas said, these are vessels. We had this kind of thing in mind when choo
  12. For the new moon (lunation number 253), the new release (Galileo) is out. The exceptions raised by the external API for other KSP mods now include an error message. Miscellaneous bugs have been fixed (most notably, the centre of mass offsets are now taken into account). See the change log for more details. We support two sets of versions of KSP: downloads are available for 1.9.1 & 1.8.1, and for 1.5.1, 1.6.1, 1.7.x. Make sure you download the right one (if you don't, the game will crash on load). For the convenience of our Chinese users, the binaries can be downlo
  13. To elaborate on @pleroy’s reply, in case you are interested in the technicalities: It is a bug, and it is exacerbated by using these specific engines. Indeed, but that would make things laughably unflyable in stock just as much as with Principia. This is true of the model (note that the J57 is from AJE modified by RO, rather than being from RP-1 itself). This is not true, and this is where the bug lies: the centre of mass is offset from the model. This is what the rapier looks like on its own, with the centre of mass shown: note that the centre of mass
  14. We cannot deal with bugs that we do not know about and cannot reproduce. We only know about one remaining instance of #2519 at this time; the issue seems to have become exceptionally rare. If you want us to investigate what happens to your plane, you may want to send it to us. This is a known incompatibility. I believe it could be resolved on the KCT side by signalling to Principia that the craft is not ready to be managed by Principia, via the vessel situation. @siimav may have more thoughts on this.
  15. In order to interact with manoeuvres you would also need an API for that; perhaps you may want to resurrect something like https://github.com/mockingbirdnest/Principia/issues/2144 (and to talk to @Butcher, who has worked on that and may have some useful insights, about it).
  16. Predictions are predictions, they come with a lot of fine print (beyond the obvious impossibility of actually predicting the future in the presence of a player, computing the future in the same way as we compute the past would be prohibitively slow, so that the predictions are approximate; this means that you need to supply additional data on how accurate you want them, computing them may require lengthening the ephemeris which can be expensive, etc.). External APIs with a lot of parameters and a lot of fine print mean more work, not just to implement them, but to maintain them in the yea
  17. For the new moon (lunation number 252), the new release (Fuchs) is out. The issues with rotation (uncontrolled spin-up, jerky motion, oscillations, etc.) introduced in Frobenius and Fubini have for the most part been solved. We are aware of one remaining case of aberrant spin-up, reported by @scimas, but this seems to be a very rare issue at this point. Prior to ignition, the manœuvre node marker on the navball for guided burns now points to the orientation at ignition, instead of following the current Frenet frame. This is more useful for manual burns (the spacecraft can be orient
  18. 2020-04-23 For the new moon (lunation number 251), the new release (Fubini) is out. Support for 1.9.1 has been added. The flight planning and orbit analysis window are now available in the tracking station, bringing into line with map view. Some changes have been made to mitigate the aforementioned issue #2519. Wild spin no longer seems to be an issue, however some unexpected oscillations arise under some circumstances. We will keep investigating this issue. Some issues that would cause crashes have been resolved. See the change log for more details. We su
  19. This issue has been reported by @nepphhh and @scimas https://github.com/mockingbirdnest/Principia/issues/2519, however I have not been able to reproduce it, which makes it very difficult to diagnose. Could you provide a stock craft that reliably reproduces the issue? I am currently unable to run RSS/RO (the only machine I have that can run that at usable speeds is about 600 km away, and given the circumstances it will be a while before I can get back to it).
  20. This was done in #2505 already. Support will thus be added in Fubini, which will be released on the next new moon, on the 23rd of April. Please don’t do that. It would make support messy, as we would need to keep track of versions built in between releases (the mod is frequently in a broken state at master). Further, building reproducibly on all three platforms may prove a challenge for you (we have a fairly robust setup based on Azure pipelines now, but this used to be a mess for years), and releasing a Windows-only build would likely lead to further confusion.
  21. Frobenius is available again. Note that if you downloaded it before March 24, 21:00 UTC, you probably have a buggy version (see #2503). Please download it again. If you have the correct version, the version string in the Principia UI says 2020032409-Frobenius-0-g21e623384639abd4bdd277a9fb722e94ee9763e4. We apologize for the inconvenience. Also note that, as mentioned in the change log for Frobenius, Principia is now incompatible with PersistentRotation, as Principia now handles rotation. Please uninstall PersistentRotation if you have been using it, otherwise the two mods will fight
  22. Important notice: we have discovered an issue in Frobenius that renders the game unplayable (rockets occasionally get flipped back-to-front while being launched). As a result, we have retracted the Frobenius binaries while we investigate the issue; Frobenius will be re-released once we have resolved it.
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