Landed craft bounces on saved game load, KSP 1.3.1

[HeleleMama]

Landing gears like LY-35 and LY-60 is kicked into the air by the ground after time-warp.

It's 1.4.2, no serious mods added.

You can also use the stock plane "Stearwing A300" to reproduce this issue.

 

 

Edited March 30, 2018 by HeleleMama
Add more info.

[Anth]

Interesting. This is NOT the same bug as 1.3.1. This is something new

Edited March 30, 2018 by Anth12
repeated line. sorry about that

[HeleleMama]

29 minutes ago, Anth12 said:

Interesting. This is NOT the same bug as 1.3.1. This is something new

Interesting. This is NOT the same bug as 1.3.1. This is something new

You can use stock plane "Stearwing A300" to reproduce this. Please inform me about your result.

[XLjedi]

1 hour ago, HeleleMama said:

This bug still exist in KSP 1.4.1.

For me it's not as bad as it was in 1.3.   In 1.3, the Ker-Bounce was so bad it would destroy any of planes hangared at the island base if I flew anywhere near them.

I saw this behavior in 1.3:

 

And for me, the same plane doesn't do anything like that anymore...  although your video is interesting, as it looks very similar to what I saw in 1.3.

 

[Anth]

Its got something to do with the back wheels not being flat on the runway (or any ground) on loading physics when it should just be flat

The debug menu shows no evidence of the ship moving up or down because of a height issues which is why there was bouncing issues on the load for the most part from 1.3.0 and 1.3.1 and I could see the ship doing so

Never had that issue from the video of 1.3.1... let me see what 1.3.1 is doing

cant reproduce that video bounce.

[HeleleMama]

10 hours ago, Anth12 said:

Its got something to do with the back wheels not being flat on the runway (or any ground) on loading physics when it should just be flat

The debug menu shows no evidence of the ship moving up or down because of a height issues which is why there was bouncing issues on the load for the most part from 1.3.0 and 1.3.1 and I could see the ship doing so

Never had that issue from the video of 1.3.1... let me see what 1.3.1 is doing

cant reproduce that video bounce.

That's weird. I firstly noticed this issue in 1.3.1 x64.  1.3.0 x64 is fine.   Both 1.4.1 x64 and 1.4.2 x64 got this same issue, only be more severe. 

My game is installed from the STEAM, I use very few assistant mods. I have the issue with or without them.

The plane won't bounce when you launch it. It only bounce when you stop a time warping or load the save.

The work around is to retract the landing gear every time after you landing. Since this issue may even flip your craft in low gravity environment.

 

I believe it has something to do with the default status of the landing gear. We all know this game has two sets of physics system, the one takes effect in time warp 5X only does very rough calculation and it only keeps tracking very basic craft status(like position and orbital speed).  Other status, like the spinning, part's bending etc.. is reset.

When a craft is landing, it compress the landing gear's spring at some degree. Which makes the craft's position lower and the gear shorter. During time warp, however, the landing gear's status is lost and got rest to its original length. Since the craft's position is lower, there is no enough room for a fully stretched(reset) landing gear. The gear is clipped into the ground and then be squished out violently by the ground when you stop warping and the accurate physics system takes effect. 

Edited March 30, 2018 by HeleleMama

[HeleleMama]

2 hours ago, Anth12 said:

Its got something to do with the back wheels not being flat on the runway (or any ground) on loading physics when it should just be flat

The debug menu shows no evidence of the ship moving up or down because of a height issues which is why there was bouncing issues on the load for the most part from 1.3.0 and 1.3.1 and I could see the ship doing so

Never had that issue from the video of 1.3.1... let me see what 1.3.1 is doing

cant reproduce that video bounce.

 

1 hour ago, HeleleMama said:

That's weird. I firstly noticed this issue in 1.3.1 x64.  1.3.0 x64 is fine.   Both 1.4.1 x64 and 1.4.2 x64 got this same issue, only be more severe. 

My game is installed from the STEAM, I use very few assistant mods. I have the issue with or without them.

The plane won't bounce when you launch it. It only bounce when you stop a time warping or load the save.

The work around is to retract the landing gear every time after you landing. Since this issue may even flip your craft in low gravity environment.

 

I believe it has something to do with the default status of the landing gear. We all know this game has two sets of physics system, the one takes effect in time warp 5X only does very rough calculation and it only keeps tracking very basic craft status(like position and orbital speed).  Other status, like the spinning, part's banding etc.. is reset.

When a craft is landing, it compress the landing gear's spring at some degree. Which makes the craft's position lower and the gear shorter. During time warp, however, the landing gear's status is lost and got rest to its original length. Since the craft's position is lower, there is no enough room for a fully stretched(reset) landing gear. The gear is clipped into the ground and then be squished out violently by the ground when you stop warping and the accurate physics system takes effect. 

After posting it, I done a little dig into the game settings.

In the Settings>General>System, there is one called "Ease in Gravity".

This one makes the gravity gradually build-up(from 0% to 100%) when the accurate physics kick in. So, apparently, it is not because the landing gear is rest, it's because the landing gear's spring is retaining its original strength when the gravity is suddenly become very low and thus kick the craft high into the sky.

This feature is meant to keep very large ship from breaking apart when physics suddenly kick in. But it's doing just the opposite for things that have a spring(like landing gears).

 

However, this only solve part of the problem. For some small craft, it's much better with this option off. For some large ones, landing gear still get clipped into the ground and completely blow away after time-warp.

 

Edited March 30, 2018 by HeleleMama
Add more info.

[Anth]

wow. The force on that front wheel was impressive. time to try turning off the easing I guess

That issue isnt happening with the stock mallard. the spring smashing off the wheel looks like its got too much power to it for some reason.

[Anth]

@HeleleMama got a copy of that craft?

[HeleleMama]

@Anth12

Here: https://drive.google.com/file/d/1frgdLKkGbUgqMTHA9wmZZ0mcuG5HOfab/view?usp=drivesdk

Edited March 31, 2018 by HeleleMama

[Anth]

[D.Brooks]6_Signal.Integrity.Issues.And.Printed.Circuit.Board.Designwww.sudupan.com.chm

? huh

[HeleleMama]

6 hours ago, Anth12 said:

[D.Brooks]6_Signal.Integrity.Issues.And.Printed.Circuit.Board.Designwww.sudupan.com.chm

? huh

Sorry, mix up with another link...lol 

https://drive.google.com/file/d/1frgdLKkGbUgqMTHA9wmZZ0mcuG5HOfab/view?usp=drivesdk

 

 

 

[Anth]

@HeleleMama Ive taken a look at the crafts you supplied, but there is no violent bouncing. Remove all mods and try again.

[HeleleMama]

6 hours ago, Anth12 said:

@HeleleMama Ive taken a look at the crafts you supplied, but there is no violent bouncing. Remove all mods and try again.

Like I said, I have already tried removing all mods(even all my mods are "indicators" not game changers). 

However, after you say so, I removed all the installation, and re-install it from STEAM. Started with all default settings and pure vanilla game files. Started a completely new game and load my ship on the runway.

Still the same, it was bouncing and the gear exploded.

PS: I also tried x32, it's the same.

 

I'm really wondering why it is fine in your game. It means a lot. Probably our differences are the root cause.

My game is from STEAM. Windows 10, x64,  ver: 1.4.2.210 en-us + Making History DLC. All default settings.

[Anth]

Have you tried deleting the entire KSP folder and then told it to verify the files? Uninstalling KSP via Steam doesnt remove all of the files

[Anth]

I changed my settings to default first by telling KSP to reset them. Restarted KSP and it worked fine

I deleted the settings file and forced KSP to recreate it from scratch forcing it to be default and your craft still worked fine.

Im thinking the next thing to do on your end is to update the video drivers.

[HeleleMama]

5 hours ago, Anth12 said:

Have you tried deleting the entire KSP folder and then told it to verify the files? Uninstalling KSP via Steam doesnt remove all of the files

That's what I'm doing exactly. The same.

4 hours ago, Anth12 said:

I changed my settings to default first by telling KSP to reset them. Restarted KSP and it worked fine

I deleted the settings file and forced KSP to recreate it from scratch forcing it to be default and your craft still worked fine.

Im thinking the next thing to do on your end is to update the video drivers.

If that's video drivers related, that will be a lot more complicate. 

To be honest, I have experienced one "no problem" situation on my end (I can't reproduce the situation now. I'm sure it was without mods but was not a clean installation either). It returned to bouncing my craft after I done a total clean installation (remove all related files and re-install it).  I believe, that good situation is some sort of fixture of old and new files. Anyway, I give up trying.

 

I'm sure you have already noticed that a lot of people is talking about landing gear issues since 1.4 release.  I have already file a bug to SQUAD's tracker, hope they can find out why. 

 

PS: The crafts I sent you @Anth12, are very well built SSOT. The "Jumper" was able to send 8ton payload to orbit with 450+ dv left and it is very easy to fly. And the "Traveller" can go most of the planet and return. Just take a look.

Edited April 2, 2018 by HeleleMama

[Anth]

The KSP gods.... *shrug*

There are issues with all the wheels and landing gear in  1.4.1/1.4.2. they dont work correctly

The jumping issues that were from 1.3.1 were issues that I found myself invested in trying to get fixed and I reported on in the prerelease and the release of 1.3.1. I believe they have been fixed

Most of the issues that are happening now are something different