P3D v4 PARTLY RESOLVED - Strange behaviour with Gmax-built hardened surface


I built a small hill with tower on top for RAF Brüggen. It has a hardened surface and it works fine so that I can drive with cars onto it. But now I noticed that all aircraft are bumping along the taxiway when they pass the hill. That's strange, because they don't move close enough to touch the hill:

The red circle shows the approx area where the aircraft are jumping when they are taxiing on the taxiway. The aircraft size doesn't matter - the problem appears by all vehicles I use. By checking the Gmax file I can't find any vertex or any other part of the model that is out of the yellow wireframe you can see on the picture.
Why is there a collision despite the fact that all passing vehicles has enough distance to the object? Each help is much appreciated.
Hi Manschy:

Although I seem to have dead links to your images above (on an I-Pad), I would suggest that you are incurring some anomalies with elevation of (virtual) polygons to which the texture surface was mapped when the "Platforms" were created.

You could inspect these objects using the MCX "Attached Object Editor":


You may also wish to try making the desired terrain shape as a 3D model, then import it into MCX, and export it as a FSX "sloped flatten".

This will result in a CVX vector BGL, containing a 'Airport Background' flatten-only GUID object that can be Geo-referenced and assigned with AMSL elevations for each vertex point, (...therefore a 'terrain-mesh-modifying' sloped flatten).

If necessary, that MCX output BGL can be decompiled into a *.BLN or *.SHP file using Patrick Germain's CvxExtractor, and 'Appended' / Imported into SBuilderX for editing and re-compilation as a CVX Vector BGL.


Ugh - hard parts, mate. I checked all platforms inside MCX and found out that all of them have orientation and position as well 0,00. Is that correct?
BTW, where can I find the FSX"sloped flatten" option, please? I can't find it under the Export Options....

Furthermore, I noticed that NO AI IS bumping anywhere! That's strange. It only happens with user-controlled aircraft obviously...
Hi Manschy:

You can export objects as a "sloped flatten" using the MCX "Export Scenery" toolbar icon.

In the "Save As" dialog box, configure 'Save As Type': "FSX Flatten File (*.BGL); click [Save] button



FYI: This will be a terrain-type CVX vector object with an assigned elevation that modifies local terrain mesh BGL display, and will already be 'hardened' ground, so AFAIK, no Platform should be needed.

However, one may need to set Terrain Complexity at 100% and Terrain Mesh Resolution at ex: 1 Meter. :pushpin:

Hope this helps a bit more. :)

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What scale did you place the model with? Anything else than zero will give weird results, because the platform doesn't scale.
@Gary: Oh, thank you. There it is, you see! Found it but now I got an error message "A placement should be specified for the object". Where may I add this coordinates?

@Arno: Do you mean in Gmax? I export the model like all my other objects. Furthermore, I reset all scales to zero now (under "Hierachy>Reset Transform and Scale")


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No, I mean when you place the mdl in the scenery.
Ah, okay. I built in Gmax a scene within two objects: The model of the hill, attached a platform by Attach Tool and then exported it both.
After this, I still use the importer and exporter settings by MCX. Never mind about the scale while exporting so far...
So do you mean, if my objects always were exported by scale 1.0, here is the mistake to export the platform by 1.0 as well? Would it be better to make two seperate mdls, one with the hill and another one with the platform only?


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I'm not talking about exporting. I'm talking about placing the mdl in the scenery, did you use a scale there?


: Oh, thank you. There it is, you see! Found it but now I got an error message "A placement should be specified for the object". Where may I add this coordinates?
Perhaps this is an appropriate time for Arno to explain the MCX work-flow required to import a terrain 3D model and export a flatten ? ;)

All we have seen thus far from Arno on that process, is this scenerydesign.org Blog post: :scratchch

arno said:

Simply model the shape you want and export it to a MDL file. Then you import the MDL into ModelConverterX and enter the coordinates of the reference point. Next under export scenery you will find the new format “FSX flatten BGL file” and this will use shp2vec to create the flatten BGL from your object.

"Simply model the shape you want and export it to a MDL file. Then you import the MDL into ModelConverterX and enter the coordinates of the reference point. Next under export scenery you will find the new format “FSX flatten BGL file” and this will use shp2vec to create the flatten BGL from your object. " :teacher:

Note that Alchemy's secret method of converting 'dross' into Gold ...is not explained in detail here. :wizard:

Hmmm... possibly Arno refers to use of MCX' "Object Placement" icon toolbar feature followed by MCX' "Export Scenery" menu item ? :idea:

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Okay, I use ADE for placing all my objects. I had a look inside my tower hill settings (when right-clicking and selecting "edit object" on the placed object). There I found a scale of 1.0000 indeed - just because I exported my hill model and the appropriate platform together. So might it be a better to maybe export them seperately and set the platform to 0.000?
Hmm - got headache the last hours o_O:cool: and I am not sure if using "fsx flatten file" may be the right solution - just because my tower hill is a really small area.

I can't understand why the shape of my hill area works perfectly above the hill itself. All the area directly nearby and around without any issue but just the small area. Maybe you will have a look onto it, please. I attached it in gmax and mdl format. Would be glad about any mistake that will be found....


Okay, I solved my problem. It's not a full solution but a partly compromise that's entirely sufficient for its usage in the scenery.

I selected the platform cover in Gmax and simply deleted a vertex section of the grass area towards the taxiway. It's only the grass section that can't be reached when you drive on the hill's asphalt area. And if you have no user drivable mowing machine, that seems to be a pretty good idea (to me at least....). So no more jumping aircraft on the taxiway but still fair usable road and storage space on the hill.

Thank you both for patiently effort to solve the problem.
Hi Manschy:

I'm glad you have achived a solution you are satisfied with. :)

However, I was intrigued as to the terrain configuration for the location you described above, so after some research, IIUC, it is here:

Google Maps: https://www.google.com/maps/@51.202252,6.1327184,130m/data=!3m1!1e3?hl=en

Google Earth Desktop Edition: 51.202252,6.1327184,130

NOTE: The *.KMZ files attached below can be double-clicked to launch Google Earth Desktop Edition at that location and angle of view of the screenshot:


According to the low resolution SRTM terrain mesh used in Google Earth Desktop Edition, the hill is ~ 10 Feet / 3 Meters above Taxiway level.

This location could either be 3D modeled as discussed above, and made into a CVX vector sloped flatten via MCX.

Alternatively, a CVX vector sloped flatten could be made in ADE or SBuilderX as adjustments to the nearby 'central' Airport Background flatten, by use of manually assigned elevations for vertices in an adjacent 'perimeter' Airport Background with a 'Flatten-only GUID'; this can also be used to "blend" the airport flatten into the surrounding terrain.

I am not certain why a Platform would be required here, but perhaps you can enlighten me as to whether you have found this necessary for creating custom animated traffic that can actually travel uphill, unlike default AI ground traffic that requires a 'level' ground surface ? :scratchch



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Thank you again for your effort, Gary.
Okay, the hill is just a model and simply a part of the tower surrounding area. To my opinion, it would be not correct to show this area without a different elevation (although the hills edges are a little more flat in reality...). So because there are a small road and several parking lots on top of the hill, I liked to create a harden surface to drive uphill with a user ridable car. I know this was not needed, but finally a nice addition.
In fact, something went wrong with harden the hills surface and I was not able to solve the problem with my skills. So I decided to simply "cut" a part of the hill sidewards to the taxiway - and it worked!
There was no need to create custom AI traffic, because the taxiway beside is on AGL.
Any other solution (thought about creating a small flatten area with a little raised altitude) was not possible because of custom used ground polygons with own textures on it. So this seems to be the best solution to me and it works really fine now :wave:.
Hi Manschy:

Thanks for that clarification, as I had not realized that you required a 3D object for the hill that must be superimposed on top of underlying G-Polys with custom seasonal textures (...and special MDL-based Material Properties / Functions ?).

I had missed seeing your threads on "ETUR redu_X - RAF Brüggen for FSX" elsewhere:



...and your "RAF Brüggen redu_X" thread here at FSDeveloper:


I see now what your objectives involve, and will follow your interesting and impressive developments with this project. :)

BTW: Although I did see in one of your threads elsewhere that you anticipated making a FSX RAF Brüggen (con-)version which should also work in P3D, I'm curious as to whether you have considered making the 3D model of the hill for P3D as a native P3Dv4.x MDL which is a solid (manifold) object rather than ex: a scalloped 'shell', such that it would be a 'non-flat' "G-Poly" to which the additional Z-Bias Material Function may be applied ...in order to control how its casting- and receiving- of shadows is rendered ? :idea:

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:cool: Currently there is no casting and receiving - it's just a simple object devided into several segments, then simply raised in different hights. Believe me, I am such a stupid developer, it will take sooo much time to get all latest technique achievements in these sceneries.....My only strength is phantasy and endurance :laughing:....and a little trick how to work with textures/sheets efficently...(maybe that way they look like casting and receiving shadows :p )..... I develop for FSX and P3D simultaneously - so the only thing that is made for v4 especially is currently the dynamic lighting - everything else seems to work fine in both sims so far, also the SODE triggered hangar doors and QRA area fence gates/flash lights....
Hi Manschy:

On the contrary; I believe your FS scenery projects to date show you to be a rather experienced developer ! :eek:

Perhaps we shall even see you implement a 'non-flat' G-Poly in native P3Dv4.x SDK format sometime in the future ! :)

Sorry, sounded like fishing for compliments, but it isn't. It's rather minor skills but with a lot of trial and error - comparable with musicians. Some bands sounds great by only playing 3 riffs (for example AC/DC). Other styles of music are so much more detailed (to my ears...for example Jazz, Classic music) and there is soooo much more technique and effort in it - still skills . Have a look here around inside the FSDeveloper forum, there are so many designer around I really admire. They did x-time more BRILLIANT sceneries in half the time I ever could create my first polygon :D. Take a search and you will see how many silly questions I asked :rotfl:....But ever got helpful and kind answers :wizard: