The Underground Kraken:Switching to landed craft catapults it into the air, logs show negative heigt

[Sethur]

Title Correction: "... catapults it into a random direction, often upwards, into the vacuum". Using "air" was just a manner of speech.

KSP: 0.90.0 Windows 32bit with -popupwindow and -force-opengl

Problem:

Pondering wether I had the great honor to discover a completely new type of Kraken. I call it: The (Terrible) Underground Kraken

On several occasions during my first 0.90 career run, crafts landed on the Mün would be violently tossed into the vacuum above, rapidly spinning and often immediately colliding with nearby rocky surfaces, causing catastrophic mission failures, rapid unplanned disassembles, frustration and sometimes hysterical laughter.

The catapult action happens either when you switch to the landed craft or when you walk towards it with a Kerbal on EVA and come to a certain distance where the physics engine for the approached craft kicks in. The first time I witnessed this was on such an EVA mission, and it was truly a sight to behold for unsuspecting Jeb Kermin to see his only return vehicle rapidly taking of, spinning violently and seconds later exploding on the ground.

One you have identified a vessel that struck the fancy of the Underground Kraken, the issue is reproducible every time. On the same EVA, I tried not walking back with Jeb but instead switching to the problematic vessel. When you do this, the physics engine is working heavily for a short while during loading (I think the timer is red, too), then the craft gets the same "donkey kick" as previously described, only this time one has a chance to safe the rapidly spinning craft if has not already exploded (the ejection angle seems to be quite random, sometimes you immediately explode, sometimes you get launched straight into the air).

Mods are all on the current version. I uninstalled everything that I didn't need for the reproduction but the landers in the affected quicksaves kept on getting attacked by the Kraken. I even tried uninstalling some suspicious mods and playing out the same landing trajectory while my craft was still approaching the surface of Mün (height >= 15 km) and the issue would still persist. When you land and exit for EVA, nothing happens until you are out of physics range (few hundred meters). Then, when you walk back or switch to the craft: bäm! As far as I remember, I even tried putting the lander on its side, but to no avail.

I initially though Mechjeb was the culprit because I was using Smart S.A.S. on the affected craft with KILL ROT enabled and I think I went out of electricity, but that wasn't it. Once I gave up on the such affected crafts, though, further mun landings went well until a certain point where it happened again, and so on.

Now the most interesting thing: The logs show a negative height of you vessel just before the Kraken strikes (i.e. the physics engine goes crazy). I had with four different vessels now, all lite-weight and with relatively few parts, i.e. standard Mun landers with only one fuel tank and an LV-909 engine. I think I used the medium lander legs on all of those.

Mods installed:

Kerbal Engineer Redux

Deadly Reentry Continued

Quick Search

Quick Scroll

Ferram Aerospace Research (tried uninstalling)

Mechjeb (tried uninstalling)

Kerbal Joint Reinforcement

Procedural Dynamics

Procedural Fairings

Active Texture Management

Chatterer (tried uninstalling)

Kerbal Attachment System (tried uninstalling)

Reproduction steps:

Hard to reproduce. Build a simple Mün lander with the medium stock landing legs, land, go on EVA, switch to your craft when you are far enough away. But I think the Kraken is quite insidious and intelligent, it only strikes when you don't expect him to do so and when you didn't quicksave before the deorbit burn

Log:

I don't have the exact logs here right now, but it show something of a negative height when the Kraken strikes.

Edited February 11, 2015 by Sethur
Minor corrections

[Vereox]

I have experienced this problem several times now as well. On Mun as well as Minmus and Ike.

Usually my problem goes like this:

I land a base or a simple lander on the surface. Then a kerbal goes on EVA. Once they reach a certain distance away from the lander/base the game stutters for a bit but all is fine. Once I have done whatever it is that I've needed to do. I start to head back to the lander with the kerbal. Then all of a sudden all hell breaks loose. The lander explodes and gets flung into space. Pieces go everywhere and the base or lander is more often than not destroyed.

As a general rule of thumb I don't have any SAS active or have any engines activated when I land something and it is staying there. (just to note)

But recently I just landed a base on Ike and sent a kerbal out to do some science a few hundred metres away. When the kerbal went 250 metres away from the base, the base suddenly started falling downwards, into the moon. It stopped at about 350 metres away. Curious, I sent the kerbal back over to investigate. Once I was essentially standing right on top the base (except that it was underground), the base suddenly popped back up to the surface, then promptly exploded. Sending parts and the kerbal into space.

Here are two series of screenshots I just took to demonstrate this bug. The first series is without the debug open, the second is with the debug open.

Javascript is disabled. View full album

Log:

https://dl.dropboxusercontent.com/u/85103666/output_log.txt

Edited February 14, 2015 by Vereox

[Vereox]

I should also add that the mods that I have installed are:

Alternate Resource Panel

Distant Object Enhancer

Environment Visual Enhancements

Ferram Aerospace Research

In-Flight Waypoints (uninstalled a while ago when first experiencing this on Mun when I sent a lander there to do a contract; but uninstalling did not solve the problem)

Kerbal Alarm Clock

Kerbal Engineer Redux

Module Manager

Near Future Solar

Procedural Fairings

Procedural Parts

StageRecovery

Surface Lights

[smjjames]

Hm, I see both of you have procedural something (besides fairings), so, I have a bit of a hunch here. Did either of you edit the landing legs in any way?

Sounds like a ground clipping issue. While not the underground kraken exactly, I've experienced something similar to what's described, the hangars from Allistas hangar mod will clip and collide with the launchpad on load and experience the same kinetic kick (or donkey kick as Sethur described it). I haven't experienced this bug with things other than the hangars initial load on launchpad.

[Vereox]

I myself haven't edited any of the parts or files. All of it is the same as any downloaded copy of the game files or mod files.

Just another note on the ground clipping. I've noticed that whenever I'm on Kerbin and I'm trying to land a plane, the game won't load the terrain in a way that causes parts to clip except for the controlling part of the craft. But when I reach about 80 m/s, the terrain loads correctly and I can land perfectly fine. Any velocity higher and the terrain doesn't load. It's actually really annoying.

Personally I think that there may be something with the way the game loads in the terrain under certain conditions, or may be way a mod interacts with the terrain code. Just my two cents.

[Sethur]

Did someone file this on the official squad bugtracker, yet? I did not take any screenshots, but Vereox could post it on: http://bugs.kerbalspaceprogram.com/projects/ksp/issues

[Vereox]

Bug added to the tracker.

[Sethur]

Thanks Vereox, I updated the tracker with my latest findings. Turns out I had another issue with clipping and missing ground on the old airfield island near the KSC, which made me suspicious. After long testing and uninstalling tons of mods (without the issue disappearing), it finally dawned on me that I was using an old settings.cfg from pre-0.90 times and did a comparison with the current stock config. Turns out that they apparently changed a line in the High Terrain Details preset that somehow determines how the ground is rendered. The clipping issue went away after I changed this and there is a good chance that this was also somehow connected with the Kraken, at least it's worth a try. Could anybody who was experiencing the Kraken report if they had the wrong entry in their respective settings.cfg? See below for a description and also see http://bugs.kerbalspaceprogram.com/issues/4128 and http://bugs.kerbalspaceprogram.com/issues/4134

The relevant part of my old (and apparently wrong) settings.cfg:

PRESET

{

name = High

PLANET

{

name = Kerbin

minDistance = 8

minSubdivision = 1

maxSubdivision = 14 <--- This is 10 now for the High preset.

Edited February 27, 2015 by Sethur
Formatting

[firda]

Still happens with 1.3.1, the only possibly relevant mod I use is Joint Reinforcement (because the game kinda sucks without it, you at least need to use advanced tweakables and auto-struts).

I just do not understand it because I am a programmer. KSP already uses kind of state, one of them being LANDED, so please, implement some workaround when loading LANDED craft, pin it in place, limit it's speed until you can detect that everything is fine!! SIMPLE!!!

 

It happens more often if you land on slope but the reason is obvious: simplified landscape and physics when far, kick-in of precision and the transition sucks.

[firda]

Looks like there is mod for this:

...just in case somebody finds this after his kerbal went too far to place the flag and has nowhere to return, because his landed ship went on a trip without a pilot.

[radonek]

On 20. 1. 2018 at 10:58 AM, firda said:

Looks like there is mod for this:

...just in case somebody finds this after his kerbal went too far to place the flag and has nowhere to return, because his landed ship went on a trip without a pilot.

Just happened to me. Thank you.