Plane bouncing on ground with my install

[jeanba]

Hello

 

My planes are often bouncing at takeoff in my install, but this is not the case with the same mission, same loadout, same plane (exactly) when crusader is checking.

Do you know wher it can come from ?

Joystick ?

Joystick sensitivity ?

 

Thank you in advance

Edited November 19, 2013 by jeanba

[Wrench]

What aircraft, in particular?? Stock or add ons? If addons, whose?

 

a butt-load of 1stGens ported over have the issue. I've been told it might be due to the wheel's axle center being "off" in MAX (meaning: SF2 reads it completely differently than SF1) sometimes can be fixed by fiddling the shock statements and (rarely) the rolling radius -or combinations thereof.

 

it can be bloody nightmare to run down, I'm here to tell!!

[jeanba]

To clarify :

 

Coupi, Crusader and I are testing the jaguar :

My install is the "base install" so Coupi and Crusader should be using the same install as mie : both have no porblem.

In addition, I have the same "bouncing problem" with Flogger23's Su-15TM revamp (http://combatace.com/files/file/14326-su-15tm-flagon-f-for-sf2-revamp/), which does not seem to be the case for other people because for me, the plane explodes before takeoff.

Add to this that for the Jag, the problem is "random" : same mission,, same loadout, sometimes it is barely noticable, sometimes ok, and sometimes my plane explodes !!!

 

FM difficulty is hard, as most other people

So I come to think there is something in my install !!!

 

Do you have any idea ?

[jeanba]

It has already been done, to no effect :(

[MigBuster]

Is it bouncing as soon as you enter the cockpit?

 

If so - when the games starts quickly move the throttle then put the throttle to zero and take off the wheelbrakes to let the jet roll. (it may be controller related if the gear shock values are ok)

[jeanba]

Thank you, I will try

 

This seems terrrain related :

For Desert terrain (vanilla) : usually no problem

For germanCE, crash on runway sometimes for both player and AI !

[+Menrva]

I once had this problem in my modded install: I removed the flightengine.ini in the flight folder and it worked mostly. I don't know the reason of this and since i needed a modded flightengine.ini (to allow better draw distance of trees and buildings) I extracted the original one with thirdwire utilities, i made the changes I wanted and it worked, no planes bouncing and exploding, or at least some that did it before now do not explode anymore. (However I also think it may be terrain related, but sometimes even with stock unmodded terrains the problem occurred). 

[jeanba]

Well I tried to remove the flihtengine.ini, but it did not improve.

On the other hand, a non modded CeGermany map, it is ok (with my "flightengine")

So it may be terrain related

[+Menrva]

Have you tried playing with FM difficulty set to normal? See if it improves the bouncing problem when using a modded terrain. Also try to fly with stock unmodded planes and see if the problem occurs too. I hope it helps.

[jeanba]

Have you tried playing with FM difficulty set to normal? See if it improves the bouncing problem when using a modded terrain. Also try to fly with stock unmodded planes and see if the problem occurs too. I hope it helps.

Well, stock aircraft are mostly ok, it is only some aircraft that I have the problem such as Flogger23's yak-25 (all) and su-15tm, and the JaguarA to alesser extent

Replacing the flightengine by the stock one improved things to some extents (unlike what I said earlier), but the problem remains

Edited December 10, 2013 by jeanba

[jeanba]

I found, it is in the flightengine file : :

 

DeltaT=0.016667

MaxDeltaT=0.0500

 

Maxdelta was at 0.2, the "vanilla" one was at 0.1, still bouncing, but at 0.05 : everything is ok 

[+Menrva]

I found, it is in the flightengine file : :

Maxdelta was at 0.2, the "vanilla" one was at 0.1, still bouncing, but at 0.05 : everything is ok 

Nice finding, jeanba! Mine one is at 0.1, the default value. I'm wondering what else these values change regarding the flight dynamics, apart from reducing the bouncing. However, as Wrench said, some planes do need new flight models since they were not updated to SF2 standards.

[jeanba]

I think that it is the maximum time between 2 FM (and other events) recalculation.

DelatT is the "initial" one, but to reduce the number of calculations, therefore CPU load the value may increase, when the calculation becomes more complex and things change very fast, the time step may become very low.

 

So the possible consequence of doing this is a loss of fps

 

0.1 is the default value for the recent flight engine.