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FS2004 Ground poly flickering and aircraft sinking into the ground

J

jeppa6640

Messages
47
Country
canada
Hi everybody

I just recently used MCX Ground Poly Wizard to do ground poly for FS9. I used to do the basic layout with sketchup, then imported dae and exported to mdl then the mcx converted it to bgl and it loads up in fs but even after raising the alt by 2 millimeters from 337.413 to 337.4132 it still makes the aircraft sink into the ground,
Screenshot 2025-05-19 111648.png
Screenshot 2025-05-22 233824.png
and the poly is flickering. Any help is greatly appreciated.
 
In FS9 the flatten altitude, airport altitude, and ground polygon altitude have to be the same value for the ground polygon to work correctly. By the way you can eliminate a step in your MCX process, Open MCX and start the ground polygon wizard. You can load your dae file into the wizard and export directly to a ground polygon bgl.

Ed
 
edphipps said:
In FS9 the flatten altitude, airport altitude, and ground polygon altitude have to be the same value for the ground polygon to work correctly. By the way you can eliminate a step in your MCX process, Open MCX and start the ground polygon wizard. You can load your dae file into the wizard and export directly to a ground polygon bgl.

Ed
Click to expand...
Hi @edphipps
Screenshot 2025-05-23 143111.png
Screenshot 2025-05-23 142308.png
Screenshot 2025-05-23 142327.png
1748021641859.png

Thanks for your info the flickering stopped that's good but the issue is the sinking only happens on the runway not on the aprons or taxiways I have no idea why is it the photoreal or ade I'm not sure everything is set to the exact altitude.
 
Just a thought ... I've seen similar symptoms where a replacement airfield is sitting on a default airfield and the altitudes of each airfield are not identical.
I don't see (or may have missed) any reference to which airfield is being worked on, so I don't know if there's a default runway underneath your scenery, but if there is that's where I'd start.
Also, if the background (photoscenery) polygon is larger than the underlying flatten, it can "sit" on any higher surrounding terrain, whilst the aircraft will sit on the flatten. In this case, a larger flatten may be necessary.
Good luck.
 
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Chris Eve said:
Just a thought ... I've seen similar symptoms where a replacement airfield is sitting on a default airfield and the altitudes of each airfield are not identical.
I don't see (or may have missed) any reference to which airfield is being worked on, so I don't know if there's a default runway underneath your scenery, but if there is that's where I'd start.
Also, if the background (photoscenery) polygon is larger than the underlying flatten, it can "sit" on any higher surrounding terrain, whilst the aircraft will sit on the flatten. In this case, a larger flatten may be necessary.
Good luck.
Click to expand...
I tried a larger flatten but still it's like even the aircraft is sinking through default runway as well and ade is not registering any flattens for some reason and idk why it's just the length of the runway no other part at all.
 
jeppa6640 said:
I tried a larger flatten but still it's like even the aircraft is sinking through default runway as well and ade is not registering any flattens for some reason and idk why it's just the length of the runway no other part at all.
Click to expand...
When you write "a larger flatten", presumably this was a flatten that was physically bigger in every dimension than the polygon you're having trouble with?
You've still not mentioned whether this is a replacement for a default airfield or if it's something you're building from scratch.
It's not unknown for the default Microsoft terrain/scenery to have problems ... I've found several whilst developing my "Airstrips of Western Europe" uploads which don't appear to have been otherwise documented.
They can be exacerbated by any mesh you may have installed.
You may need to go back to "square one" in a basic default FS9 installation with no other add-ons and ascertain at which point the symptoms occur by adding the various features one at a time.
I can appreciate the perceived desire to "keep things secret", but the more information/details you share the better chance there might be of finding a resolution.
It might even be worthwhile checking that there's not another "rogue" installation for this airfield lurking in another directory somewhere.
AFCAD2 can be very useful in this regard, as it will give you a list of every instance of a particular ICAO code, even if it's not the active scenery.
This information can help point to where unwanted flattens etc. might be "hiding" ;)
It can also help, if you're not doing so already, to have your development scenery folder at the very top of your Scenery Library, that way you've got a better chance of overwriting anything that may otherwise cause problems, though this isn't foolproof, as some features can be cumulative rather than replacing each other.
 
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A question for the OP: Did you make a SCASM Area16N flatten with ADE in FS9 mode ? :scratchch

GaryGB
 
Chris Eve said:
When you write "a larger flatten", presumably this was a flatten that was physically bigger in every dimension than the polygon you're having trouble with?
You've still not mentioned whether this is a replacement for a default airfield or if it's something you're building from scratch.
It's not unknown for the default Microsoft terrain/scenery to have problems ... I've found several whilst developing my "Airstrips of Western Europe" uploads which don't appear to have been otherwise documented.
They can be exacerbated by any mesh you may have installed.
You may need to go back to "square one" in a basic default FS9 installation with no other add-ons and ascertain at which point the symptoms occur by adding the various features one at a time.
I can appreciate the perceived desire to "keep things secret", but the more information/details you share the better chance there might be of finding a resolution.
It might even be worthwhile checking that there's not another "rogue" installation for this airfield lurking in another directory somewhere.
AFCAD2 can be very useful in this regard, as it will give you a list of every instance of a particular ICAO code, even if it's not the active scenery.
This information can help point to where unwanted flattens etc. might be "hiding" ;)
It can also help, if you're not doing so already, to have your development scenery folder at the very top of your Scenery Library, that way you've got a better chance of overwriting anything that may otherwise cause problems, though this isn't foolproof, as some features can be cumulative rather than replacing each other.
Click to expand...
Actually my friend made the photoreal and initially only a small part of ground poly was making the aircraft sink in the ground but now it's the whole length of the runway. Regarding the airport it's default but I modified in ade and compiled into the same scenery folder as the ground poly. All other parts of ground poly is solid and the shadows also appear but not the runway.
 
jeppa6640 said:
Actually my friend made the photoreal and initially only a small part of ground poly was making the aircraft sink in the ground but now it's the whole length of the runway. Regarding the airport it's default but I modified in ade and compiled into the same scenery folder as the ground poly. All other parts of ground poly is solid and the shadows also appear but not the runway.
Click to expand...
Ah well ... it's all guesswork without any firm details ... I'll let you get on with it.
Good luck.
 
Hi again:

I shall maintain the suspense already in progress, so the OP can maintain (some) of the element of surprise when released. ;)


I assume the FS9 'default' airport that the OP loaded in ADE9x is rendered using FS9 default terrain mesh and other BGL files.


The FS9 Default ARP Altitude in AB926140.bgl for that RWY-18/36 is 319.430 Meters AMSL according to ADE9x.


The FS9 Default RWY-36 Start Terrain Altitude in DW120N90.bgl for that RWY is 304.0 Meters AMSL according to TMFViewer.

The FS9 Default RWY-18 Start Terrain Altitude in DW120N90.bgl for that RWY is 320.0 Meters AMSL according to TMFViewer.


RWY Wheel sinking may vary according to Altitude AMSL assigned to vertices of the SCASM Area16N Flatten Polygon.


RWY Wheel sinking occurs if Altitude AMSL assigned to the SCASM Area16N Flatten Polygon is less than the ARP.

RWY Wheel sinking may occur if Altitude AMSL assigned to '_ALT' or '_TER' BGLs in Scenery\World\Scenery is less than the ARP.

http://web.archive.org/web/20181108.../20268/l/210825-what-bgl-files-can-ade-create


RWY Wheel sinking may occur if Altitude AMSL assigned to a "G-Poly" BGL exceeds that of the ARP ...and the Area16N Flatten.


337.4132 Meters G-Poly (-) 320.0000 Meters FS9 Default RWY-18 Start Location = 17.4132 Meters AGL to FS9 Terrain DEM

337.4132 Meters G-Poly (-) 304.0000 Meters FS9 Default RWY-36 Start Location = 33.4132 Meters AGL to FS9 Terrain DEM


Personally, I would not use anything over 320 Meters AMSL for a matching Altitude of the ARP, Area 16N Flatten, and G-Poly.


RWY wheel sinking occurs if Altitude AMSL assigned to the SCASM Area16N Flatten Polygon is below 319.430 Meters.


320.0000 Meters Terrain (-) 319.430 Meters ARP = 0.57 Meters

With a 320.0000 Meter AMSL flatten, there may be a 0.57 Meter embankment in the terrain outside the NW end of the RWY.


320.0000 Meters Terrain (-) 304.000 Meters Terrain = 16.0 Meters

With a 320.0000 Meter AMSL flatten, there will be up to a 16.0 Meter embankment in terrain outside the RWY 18/36 axis.


I hope I got all this typed correctly at this late hour, for your consideration. :)


PS: To make your local FS9 terrain "As Real As It Gets", you can use SBuilder to make sloped LWM-3 flattens for blending etc. :idea:

SBuilder Help > {Search} tab > query string: Flatten > LWM Scenery > LWM tilted polygons

GaryGB
 
Last edited:
GaryGB said:
Hi again:

I shall maintain the suspense already in progress, so the OP can maintain (some) of the element of surprise when released. ;)


I assume the FS9 'default' airport that the OP loaded in ADE9x is rendered using FS9 default terrain mesh and other BGL files.


The FS9 Default ARP Altitude in AB926140.bgl for that RWY-18/36 is 319.430 Meters AMSL according to ADE9x.


The FS9 Default RWY-36 Start Terrain Altitude in DW120N90.bgl for that RWY is 304.0 Meters AMSL according to TMFViewer.

The FS9 Default RWY-18 Start Terrain Altitude in DW120N90.bgl for that RWY is 320.0 Meters AMSL according to TMFViewer.


RWY Wheel sinking may vary according to Altitude AMSL assigned to vertices of the SCASM Area16N Flatten Polygon.


RWY Wheel sinking occurs if Altitude AMSL assigned to the SCASM Area16N Flatten Polygon is less than the ARP.

RWY Wheel sinking may occur if Altitude AMSL assigned to '_ALT' or '_TER' BGLs in Scenery\World\Scenery is less than the ARP.

http://web.archive.org/web/20181108.../20268/l/210825-what-bgl-files-can-ade-create


RWY Wheel sinking may occur if Altitude AMSL assigned to a "G-Poly" BGL exceeds that of the ARP ...and the Area16N Flatten.


337.4132 Meters G-Poly (-) 320.0000 Meters FS9 Default RWY-18 Start Location = 17.4132 Meters AGL to FS9 Terrain DEM

337.4132 Meters G-Poly (-) 304.0000 Meters FS9 Default RWY-36 Start Location = 33.4132 Meters AGL to FS9 Terrain DEM


Personally, I would not use anything over 320 Meters AMSL for a matching Altitude of the ARP, Area 16N Flatten, and G-Poly.


RWY wheel sinking occurs if Altitude AMSL assigned to the SCASM Area16N Flatten Polygon is below 319.430 Meters.


320.0000 Meters Terrain (-) 319.430 Meters ARP = 0.57 Meters

With a 320.0000 Meter AMSL flatten, there may be a 0.57 Meter embankment in the terrain outside the NW end of the RWY.


320.0000 Meters Terrain (-) 304.000 Meters Terrain = 16.0 Meters

With a 320.0000 Meter AMSL flatten, there will be up to a 16.0 Meter embankment in terrain outside the RWY 18/36 axis.


I hope I got all this typed correctly at this late hour, for your consideration. :)


PS: To make your local FS9 terrain "As Real As It Gets", you can use SBuilder to make sloped LWM-3 flattens for blending etc. :idea:

SBuilder Help > {Search} tab > query string: Flatten > LWM Scenery > LWM tilted polygons

GaryGB
Click to expand...
Thank you for your detailed reply but towards the end there about sbuilder the thing is it's giving me a runtime error 339 that's why it's making it a lot harder than it aldready is I asked several people about this but sbuilder says the mscomctl.ocx or that is missing when I clearly have it.
 
GaryGB said:
Hi again:

I shall maintain the suspense already in progress, so the OP can maintain (some) of the element of surprise when released. ;)


I assume the FS9 'default' airport that the OP loaded in ADE9x is rendered using FS9 default terrain mesh and other BGL files.


The FS9 Default ARP Altitude in AB926140.bgl for that RWY-18/36 is 319.430 Meters AMSL according to ADE9x.


The FS9 Default RWY-36 Start Terrain Altitude in DW120N90.bgl for that RWY is 304.0 Meters AMSL according to TMFViewer.

The FS9 Default RWY-18 Start Terrain Altitude in DW120N90.bgl for that RWY is 320.0 Meters AMSL according to TMFViewer.


RWY Wheel sinking may vary according to Altitude AMSL assigned to vertices of the SCASM Area16N Flatten Polygon.


RWY Wheel sinking occurs if Altitude AMSL assigned to the SCASM Area16N Flatten Polygon is less than the ARP.

RWY Wheel sinking may occur if Altitude AMSL assigned to '_ALT' or '_TER' BGLs in Scenery\World\Scenery is less than the ARP.

http://web.archive.org/web/20181108.../20268/l/210825-what-bgl-files-can-ade-create


RWY Wheel sinking may occur if Altitude AMSL assigned to a "G-Poly" BGL exceeds that of the ARP ...and the Area16N Flatten.


337.4132 Meters G-Poly (-) 320.0000 Meters FS9 Default RWY-18 Start Location = 17.4132 Meters AGL to FS9 Terrain DEM

337.4132 Meters G-Poly (-) 304.0000 Meters FS9 Default RWY-36 Start Location = 33.4132 Meters AGL to FS9 Terrain DEM


Personally, I would not use anything over 320 Meters AMSL for a matching Altitude of the ARP, Area 16N Flatten, and G-Poly.


RWY wheel sinking occurs if Altitude AMSL assigned to the SCASM Area16N Flatten Polygon is below 319.430 Meters.


320.0000 Meters Terrain (-) 319.430 Meters ARP = 0.57 Meters

With a 320.0000 Meter AMSL flatten, there may be a 0.57 Meter embankment in the terrain outside the NW end of the RWY.


320.0000 Meters Terrain (-) 304.000 Meters Terrain = 16.0 Meters

With a 320.0000 Meter AMSL flatten, there will be up to a 16.0 Meter embankment in terrain outside the RWY 18/36 axis.


I hope I got all this typed correctly at this late hour, for your consideration. :)


PS: To make your local FS9 terrain "As Real As It Gets", you can use SBuilder to make sloped LWM-3 flattens for blending etc. :idea:

SBuilder Help > {Search} tab > query string: Flatten > LWM Scenery > LWM tilted polygons

GaryGB
Click to expand...
Also in ade I set the flatten to 337.413 and later even increased to 340 but it seems like ade doesn't register changes sometimes.
 
jeppa6640 said:
Thank you for your detailed reply but towards the end there about SBuilder the thing is it's giving me a runtime error 339 that's why it's making it a lot harder than it already is I asked several people about this but SBuilder says the mscomctl.ocx or that is missing when I clearly have it.
Click to expand...

Windows infers that it always provides what we need to do anything in the world with each installer; but it does NOT.

Windows only supplies the newest- and a few recent- run time file dependencies with each Windows version installer.

Thus, we must find / install legacy 'runtimes' ourselves, since MS will delete links to older files for older Windows versions.

MS does not want us to keep using older versions of Windows, and com0pels us to buy / use new software on new hardware.


Since you are working in FS9, the LWM3 task may require SBuilder for FS9, so one must install the cited MSMCOMCTL.OCX.


The version of Windows you have installed may determine where in the Registry that dependency must be registered.

What numeric version of Windows are you using, and is it a 32-bit (aka "x86") or 64-bit (aka "x64") version ?


Some query results on this process related to installing support files required by SBuilder for FS9 :

https://www.google.com/search?q=site:+www.fsdeveloper.com+GaryGB+SBuilderX+runtime+error+339&client=firefox-b-1-e&sca_esv=2d8cfefb39b54423&channel=entpr&ei=_aYzaNhU8omm1A-fv8apBQ&ved=0ahUKEwiYx6i24r-NAxXyhIkEHZ-fMVUQ4dUDCBA&oq=site:+www.fsdeveloper.com+GaryGB+SBuilderX+runtime+error+339&gs_lp=Egxnd3Mtd2l6LXNlcnAiPHNpdGU6IHd3dy5mc2RldmVsb3Blci5jb20gR2FyeUdCIFNCdWlsZGVyWCBydW50aW1lIGVycm9yIDMzOTIFECEYqwIyBRAhGKsCMgUQIRirAkjjHVChBlihBnABeACQAQCYAXigAXiqAQMwLjG4AQzIAQD4AQL4AQGYAgKgAoABwgIIEAAYsAMY7wWYAwCIBgGQBgKSBwMxLjGgB_MFsgcDMC4xuAd8&sclient=gws-wiz-serp


IIRC, the easiest way to get SBuilder running without manually registering the required components and rebooting Windows:

https://sourceforge.net/projects/vb6extendedruntime/

https://sourceforge.net/projects/vb6extendedruntime/files/latest/download


There may still be legacy versions of some other runtime files that are required for FS9 which might generate error messages.

But no worries, as there is a lot of fun yet to be had in FS9, once one has provided it with what it needs. ;)

GaryGB
 
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jeppa6640 said:
Also, in ADE I set the flatten to 337.413 and later even increased to 340, but it seems like ADE doesn't register changes sometimes.
Click to expand...

The "_TER" file is a SCASM flatten file, and the "_ALT" file is the FS system-wide Altitude adjustment for the airport in question.

In some cases the "Stub" airport file that ADE calls the "_ALT" file is overlooked by end users when assigning ARP altitudes.

The "_ALT" file may need to be manually removed while testing new ARP altitudes for the airport in question.


SCASM G-Polys may need manual adjustment of the VTP Layer Number to achieve best display with ARP, _ALT and _TER files.

IMHO, Arno's MCX G-Poly Wizard is the best method to use for fine-tuning that VTP Layer Number to troubleshoot a G-Poly.


BTW: The ADE Manual is here:

https://www.fsdeveloper.com/downloads/manual_english_165.zip


There are a number of other threads here at FSDEV which may help resolve "_ALT" file issues with ARPs and SCASM G-Polys.

https://www.google.com/search?q=site:www.fsdeveloper.com+ADE+_ALT+file&client=firefox-b-1-d&ei=0EBfYbT1C8rk5NoPhcGl6A8&ved=0ahUKEwi0neOV-7jzAhVKMlkFHYVgCf0Q4dUDCA0&oq=site:www.fsdeveloper.com+ADE+_ALT+file&gs_lcp=Cgdnd3Mtd2l6EAxKBAhBGAFQzPEHWMP0B2CrhwhoAXAAeACAAVqIAZoBkgEBMpgBAKABAcABAQ&sclient=gws-wiz


Feel free to inquire further if more info is required. :)

GaryGB
 
Last edited:
jeppa6640 said:
https://www.fsdeveloper.com/forum/threads/wheels-sink-into-groundpolys-solved.441313/ this thread has the exact same issue as me, except its p3d (with) the very same problem.
Click to expand...

FS2002, FS2004, and P3D all use SCASM G-Polys, but FSX can not, so Arno "emulates" micro elevation increment changes for FSX "quasi-G-Polys" to approximate the equivalent of VTP Layer Numbering changes in SCASM G-Polys.

In your case (FS9), we can only use a SCASM G-Poly (...which actually is less problematic than the 'FSX-only' G-Poly method).

I would first remove the "_ALT" file in [FS install path]\Scenery\World\Scenery before trying to change any of the Altitudes here.


I'll take a look at the scenario at your airport location further this evening, and will reply. :)

GaryGB
 
Last edited:
GaryGB said:
FS2002, FS2004, and P3D all use SCASM G-Polys, but FSX can not, so Arno "emulates" micro elevation increment changes for FSX "quasi-G-Polys" to approximate the equivalent of VTP Layer Numbering changes in SCASM G-Polys.

In your case (FS9), we can only use a SCASM G-Poly (...which actually is less problematic than the 'FSX-only' G-Poly method).


I'll take a look at the scenario at your airport location further this evening, and will reply. :)

GaryGB
Click to expand...
Thanks you do you need my ground poly with the my whole CYVO folder to you maybe tomorrow if you want.
 
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