Problem Planet's surface instability.

[Cizurator]

Hi,
I'm creating a new planetary system. It is not my first one, so I felt quite self-confident, until I encountered this problem: With increasing distance from the star, the planet's surface becomes unstable - it bounces more and more. When landed, a landed vessel (f.e. DeltaGlider) is standing still, but when i touch the hover engines, it starts to jump, over and over. The instable surface kicks it. I know this happens to REALLY FAR objects because of orbital accuracy issues. I encountered this when I created far parts of NEAREST SYSTEMS addon. Instability of a planet was understandable some 300AU far from the Sun. But what I have here, are 5 planets in normal distances circa from 40 to 200 million km from the star. All of them do bounce anyway. And classicaly, the further from the star they are, the more they bounce. I checked all the config parameters, including the star. I even downloaded some planetary addons to compare them with mine. I found no difference, no potential source of this problem. The standard Solar system planets are OK, like usually. But nothing changes the instability of my planets. How to get rid of that?

I'm working through a new, clear installation of Orbiter. My cfg's are attached below. As you may notice in the system cfg, many more planets are planned, but I can't go on without getting rid of my planet's epilepsy.

Thanks for any explanation or help!

Cizurator

 

[Hlynkacg]

Haven't actually looked at your configs but Orbiter defines all positions relative to the Sun. Further you are from the sun the less precise the position. This is ordinarily not an issue over normal interplanetary distances but it's the main thing that prevents the modelling of interstellar travel in Orbiter.

Just how far out are we talking?

 

[Cizurator]

PROBLEM SOLVED. (not solved at all, see below)

I accidentally changed the "Epoch = 2005.41409993155" parameter to 2665.41409993155 and than used copies of this first cfg as base for other planets - the problem spread to all of them. Returned to default number (from default Rhea config) and that planet headbang is over.:headbang:

 

[Cizurator]

PROBLEM NOT SOLVED AGAIN. Epoch maybe has some effect, but doesn't cause the whole thing. Some of my planets are OK now, but some of them still shaking - it's quite hard to land even when your descend speed is 0.1m/s. It kicks the ship over and over again, until it finally finds "zero" on the surface.

 

[BrianJ]

Hi,
just gave your cfg's a quick try.
Try this:
Set the LAN_MJD parameters closer to present day.
Increase the PrecessionPeriod for "Hynarro" by x10000
Any good?

 

[Cras]

what is your frame rate?

and how much gravity is on this planet?


Orbiter does not deal well with low gravity worlds and high frame rate. You will find it almost impossible to land if your frame rate is high enough, even if you are relatively lose to the Sun.

 

[Cizurator]

Hi,
just gave your cfg's a quick try.
Try this:
Set the LAN_MJD parameters closer to present day.
Increase the PrecessionPeriod for "Hynarro" by x10000
Any good?

Thanks for your effort, but no effect. I have just simplified all the cfg's to include only necessary parameters. The problem has decreased to acceptable level on big planets, but all objects roughly below the size of the Moon keep bouncing. The speed of side rotation also has some effect on how much it bounces, but it is not the reason. The reason is still there, reduced, but still making trouble.

Here's an example - a moon Bödrel. No atmosphere, small, weak gravity. It's surface is instable even after simplification of my configs. It is still hard to reach 0.0 m/s on the surface. ....

This is how all my cfg's look like now. If we find the problem, it might be appliable to all other planets.

 

[Cizurator]

what is your frame rate?

and how much gravity is on this planet?


Orbiter does not deal well with low gravity worlds and high frame rate. You will find it almost impossible to land if your frame rate is high enough, even if you are relatively lose to the Sun.

I have stable 60 FPS.
Yes, gravity and side rotation have effect on how much it bounces off the surface, but it is not the reason. After my simplification changes, only small moons bounce (roughly from the size and gravity of Mimas to size and gravity of the Ganymedes). Bigger planet's (super-Earths) bouncing is not detectable anymore. I've uploaded an example of my "bouncing moon" Bödrel above.