Flickering Trajectories (Actual, Maneuver Node and Mission Orbits)

[JulienJaden]

There may be some information on this somewhere but searching for any variation of "flickering" has only sent me on a wild goose chase through dozens of mod threads with nothing actually applicable to this issue.

For the record: The version of KSP I am playing right now (0.90) has been modded with B9 and Station Science BUT this error already occured in vanilla and is completely unrelated to the mods - It is a game bug that has not increased (or decreased) in frequency due to the mods, so this belongs here in the unmodded support section.

To the problem at hand: KSP makes the trajectories of space crafts flicker and jitter uncontrollably. This is true for all forms of them but particularly for the actual trajectories (which then even change their radius) and for maneuver node trajectories (which makes planning precise trajectories so fun I want to bite the heads off baby Kerbals) which also affects the waypoint on the navball - it jitters around, as does the delta-V (and if the trajectory depends on 0.1 m/s in the right direction, a flickering range of 30° and +/- 0.5 m/s is not acceptable).

Now, how do I know it's not the gravity of a planet or moon affecting the trajectory?

Well, 1) this occurs regardless of whether I'm in close orbit (but outside the atmosphere) or in high orbit and far enough away from any moon.

And 2) time acceleration cancels it. Entirely. No flickering on the navball or of the trajectories. And from the Space Center view, everything is nice and stable. But as soon as a I take control, it starts again.

I invested two hours in placing a satelite in high orbit over Kerbin (around 10 million meters) with minimal deviation and even without the unprecise camera and moody-at-best maneuver tuning, it was a pain, but with the trajectory "adjusting itself" for no reason and maneuvers being made nigh-on impossible by the flickering at the level of precision required to complete the mission, I just gave up and (thank god for my custom save files) loaded a save before this mission that has been doomed from the start.

From what I can tell, it gets worse the bigger the numbers are. For smaller trajectories, it was awful and goddamn annoying but manageable - Munar orbits are not too much trouble. But with the mission above, it was just plain not doable. I cannot even imagine the kind of torture a mission to another planet must be with this bug.

[sal_vager]

Sounds like you're trying to achieve absolutely circular orbits which are never needed in KSP, and that you have a contract to place a satellite but are getting frustrated because it won't complete, not realising you are 180 degrees off (in other words, flying backwards)

Being 0.1 m/s off when doing a burn for a manoeuvre node is not just perfectly fine, it's far more accurate than you need, if it bothers you that much then use RCS to fix that last 0.1 m/s.

There's floating point inaccuracies with big orbits, they are projections of where you should end up but being far from the origin (your craft) they won't be perfect.

Don't worry about it preventing you from reaching other planets though, it's perfectly possible, hundreds of thousands of KSP players manage it fine

This issue has been around forever, it's as good as Squad can make it and rather than being a bug, think of it as a feature

Of course, if you happen to be suffering from this more than most there may be a reason why, but you didn't provide any screenshots, logs or system info so there's very little we can do to help, sorry.

Please see the stickies at the top of the support section.

[JulienJaden]

Actually, the orbit I have to achieve is elliptic and the closest I got to completing the mission was about 1,000 meters off on either side.

And the contract does not ask for any kind of specific orientation (other than the angles which I got right to about 0.5° or something like that).

But regardless of the mission, the flickering is there and you are dismissing that as if it was just my imagination and frustration over my own ineptitude...

Providing screenshots of something that jitters is pretty much impossible, since a picture won't capture the erratic changes.

Here's a link to my current quicksave. The mission I tried to do was the one for the satellite in orbit around Kerbin.

Like I said, the error also occured in other places and is not at all specific to this mission but I still found it to be unbearable (as opposed to otherwise simply frustrating) in this mission in particular.

Also note that my rig runs a 64-bit Windows system which apparently means I'm doomed?

[sal_vager]

Not doomed, you got KSP to work this far, but the jittering isn't making sense without maybe a vid of the issue, could be the orbits are flickering due to anti-aliasing, or actually moving due to the bug with the claw if you're using that, so you see without enough info we can't begin to figure it out.

If your save has mod parts then I'm not going to be able to load it right away but you said it occurs with stock.

Contracts that specify an orbit will paint the requited orbit in space for you to match, the dots moving around the orbit show the required direction, as long as you get close it'll work fine.

Turns out I can't load your save at all, it's bugged with null ref errors, maybe that's related and you need to try a new save?