(potential bug) VAB vehicle in PlaneHangar makes game very very sluggish on runway

[Justin Kerbice]

Hi,

I just encounter a strange issue with KSP, when I use vehicle like the AV-40B (a amphibious bulldozer made of rockets parts, avail here) for example, or made some rocket base vehicle (fuel tank + engine) + vertical design, the game run very very slow on the runway. So slow that it's just unplayabale at all !

I discover this might happens if we have some (amount still to define) debris around and/or flights in progress. A fresh new game doesn't have this issue at all.

Can someone confirm that please ?

[Streetwind]

I have had a similar experience when using jetplane parts in the VAB (which would be the opposite of what you were doing).

Experimented with jet engine equipped liftoff boosters. One intake, one jet fuel fuselage, one tricoupler, three engines - this six-part booster assembly will freeze my 4.2 GHz Haswell CPU for 1-2 seconds when I move it to touch a radial decoupler and it switches to 6-fold symmetry. The same computer can effortlessly handle subassemblies of 50+ pure rocket parts in the same scenario without even a noticable slowdown.

Upon pressing launch with a jet booster equipped rocket, the loading time is also vastly increased (four to five times as long).

[Mobjack]

I had a complicated craft sitting on my launchpad and it slowed down all my planes on the runway.

Once I recovered that rocket to clear the launchpad, the game sped up. Make sure you don't have any debris or extra ships lying around because they can lag you.

[Justin Kerbice]

@Mobjack: it may be related to debris (as with one profile and some "running" flights, no such issue) but it's not the point to make some cleaning. Is it possible to be also a Unity bug and/or a use of Unity by KSP (as usually non visible object may be ignored at all, far far away objects can also be reduced, but sadely KSP don't seems to have LOD mecanism yet).

And more than just that, it's only occured when we mix parts type with assembly location. A rocket made in VAB and put on launch pad works good, the "same" stuffes put on runway and... take a coffee, another coffee, sleep a few hours if you can, come back... no still lagging like hell. So there is something wrong there.

[DeMatt]

Are you actually assembling the SPH version of the rocket IN the SPH? Or are you modifying the .craft files and transferring the rocket that way?

Because I just ran a test - build the same craft in both the SPH and the VAB - and had no lag problems on either end.

[Claw]

Hmm, I tried both things.

I built a rocket in the SPH and launched it from the runway, vertically. I then built an airplane in the VAB and launched it from the launch pad, vertically and horizontally.

I didn't experience any more/less lag than normal. Can you provide any more details? Like DeMatt said, are you doing any .craft file transfers? Any mods? How big of a craft are you talking about?

Thanks

EDIT: That bulldozer looks pretty intensive. Is that maybe part of the problem?

Edited February 8, 2014 by Claw

[Justin Kerbice]

No transfer at all, just crash a few ships around at low speed (rover are good for making debris ) and retry. IT may also depend on other factors, I hope not.

[Claw]

No transfer at all, just crash a few ships around at low speed (rover are good for making debris ) and retry. IT may also depend on other factors, I hope not.

Ahh, so it sounds a bit more complicated than just "making a rocket in the SPH." If you can repeat the same laggy results, then post more details about what you did and what is around you so that maybe others can duplicate. If it is a bug, then it might be worth submitting.

[DeMatt]

No transfer at all, just crash a few ships around at low speed (rover are good for making debris ) and retry. IT may also depend on other factors, I hope not.

Ahhh, I see your problem. The debris.

If a "ship" is within the physics rendering distance (2.5 km of the "ship" you're piloting), it gets rendered. So, 100-200 parts for your first smashed rover, plus 100-200 parts for your second smashed rover... etc. etc., plus 200 parts for your piloted rover, and all of a sudden your computer is rendering 1000+ parts and overloading.

Clean it up. Go to the tracking station, select debris-ships, and start recovering/terminating them. Go into the options and set "Max Persistent Debris" down to zero. Then stop playing with "pretty" ships like the AV-40B and start playing with "functional" ships of your own design.