Start position, collision siruation ??

[hjwalter]

Hi All,

 

After many years of FS9 experience, in fact ever since it's launch, I've suddenly run up against something completely new and never even heard of before.

 

I start up a previously existing and problem free flight at one of my long existing addon French airfields (LFEC) and completely unexpectedly get the following message:

 

"You are starting in a location in which your aircraft will collide with another object. Choose a different starting location." The flight then closes and the saved flights menu re-appears.

 

Re-starting the same flight ........ same message.

 

I've deleted the whole airfield folder and have replaced it by an older backup, including it's related Afcad file ........ same message.

 

The only way to then get to the problem airfield is to start up a flight at another airfield and to then "Go to" the problem airfield but everything looks quite normal and "as usual" when slewing around there.

 

Saving a new start up flight there and overwriting the existing one ........ same message.

 

The "collision" object seems to somehow be related to the very simple terminal building because during systematic testing, whereby the "culprit" BGL file was de-activated, the problem message disappeares, as does the terminal itself. However, the mystery deepens because the whole airfield folder has been replaced by a backup and that includes the "culprit" BGL file and the Afcad file concerned.

 

Only when a flight is saved at the same airfield but very far from it's original and previous correctly working position, does everything seem to work normally again, but my question remains:

 

What could have somehow changed to create the "collision" problem in the first place ? Some kind of invisible scenery object maybe ?

 

Ideas anyone ?

I thank you in advance for any suggestions.

 

Regards

 

Hans

 

 

[wobbie]

Switch 'Crash Detection' off!

[johnhinson]

Yes, it will almost certainly be an invisible collision object. This is not an unknown issue, especially in add-on sceneries where removed buildings often seem to leave their collisionability*.

The only solution I have ever seen suggested is to turn off crash detection in Settings > Realism. Mine has been "off" for over 20 years!

 

The only thing I can think of that could have changed for you is that it has accidentally been turned "on".

John

 

* - no such word, of course, but it rolls off the tongue nicely!

[Tom Gibson]

If you do not wish to turn off crash detection (mine is turned off), you could Import that BGL file into ModelConverterX, and press the Display Crash Boxes button.  Then use the green arrows in the upper left to move between objects (if there is more than one).  When you find the terminal, check where the crash boxes are.  If very large, click the Herarchy Editor button and click the Collision Part words on the left.  Then press the Remove button in the upper right.   The crash boxes should disappear.

 

If that is not the problem object, use the green arrows until you find it.

 

Then use Export Scenery (not Export Object) to save the updated BGL file.  Use that in the scenery instead.

 

Do this on a COPY of the original file - store the original in the parent (main) folder for safekeeping.

 

Hope this helps,

[jgf]

52 minutes ago, Tom Gibson said:

If you do not wish to turn off crash detection (mine is turned off)

 

Ditto.  I would prefer having it on but it doesn't affect AI aircraft and I was tired of going down in flames during approach when an AI flew through me and continued to land unscathed ....I want the AI scathed also!

 

Thanks for the info on finding those invisible walls, I've dumped a couple of add-on airports due to plowing into them.

[hjwalter]

Thanks guys for your reactions. However, I could not find the simple "turn on/off crash detection" anywhere. What I did find was "Ignore crash damage" and that has been ticked as being "on" for as long as I've been using FS9. I had followed the "settings/realism" path from the FS9 openings screen.

 

I then dis-assembled the (culprit) BGL concerned but found that all the called for textures were present and were looking completely normal as mipped DXT1s, without any of them being blank.

 

However, after further testing I found purely by chance that the photographic satellite airfield surface itself needed a flatten, which was quickly made and put in place. Then came the next surprise, in that suddenly a forrest which I had positioned very long ago behind the terminal and via the EZ object placement program, was now floating high in the sky, most probably on top of some kind of invisible elevation spike or mountain ??? A further flatten solved this new problem ....... and my collision problem had now even disappeared as well !!

 

Could such a seemingly "hard" but invisible mountain have been the cause of my collision problem because it certainly seems that way. All this while I've always believed that scenery objects were primarily "soft" and that has always included mountains.

Purely for inquisitiveness reasons I will re-store the "collision" situation tomorrow and will then try to fly through the invisible mountain ........ or of cause crash into it.

 

Where this "collision mountain" had in fact come from and when remains a mystery.

 

 

jgf,

 

AI planes getting in your way while you are approaching an airport yourself can be avoided by using a program called "AI Smooth", which I've been using successfully for years. Works great.

 

Regards

 

Hans

[Sweetd31]

23 hours ago, johnhinson said:

Yes, it will almost certainly be an invisible collision object. This is not an unknown issue, especially in add-on sceneries where removed buildings often seem to leave their collisionability*.

I had this issue with airport mods, once deleted it fixed. 

[hjwalter]

Hi Guys,

 

In a test situation using a backed up version of the "collision" airfield, which still had my added forrest floating high up in the air, I took off in a default Cessna and was actually able to fly under the forrest without crashing into the invisible mesh spike or mountain under that floating forrest.

 

Well, I'm now out of options on this issue but anyway, my initial problem is now solved but it remains somewhat frustrating because I don't understand why and/or how. A FS9 bug maybe, one that has been hiding somewhere for years ???

 

Anyway, long live FS9 !!

 

Hans