P3D v4 Terrain Slope Flatten Poly

#1
Hey,

Been using ADE for quite some time and it's a fantastic tool to create/improve airports in the sim but I've run into a small issue that I am fairly certain is due to my own mistake somewhere. Nevertheless, I've searched through the forum here and looked up the FAQ which did help to an extent but I still can't figure out a way around it. Excuse my lack of explanation skills but I trust it would communicate the majority of the information without much use of tech lingo.

I've been working on creating a brand new airport (VEPY) which has only just been added to the navigation database around the world. The airport is carved into the side of a mountain in India.
Having created the base AFCAD and the general layout of everything on it, the issue at hand became what the title of this thread has already hinted upon - trying to create a gradual transition between the flat airport to the surrounding hilly terrain, specifically step down terrain slopes.

Going by the forum, I found a thread where a user recommended triangular polys to create an efficient and well-stitched slope. Before that, I was simply using rectangular shapes which resulted in the area around the field all flat but everything else into a deep ditch with a strong fall. So I created the triangular polys where the terrain needs to slope down and it worked well for the runway ends but the problem appeared trying to do the same along the length of the runway (see screenshot).
What you see here are upright triangles as well as upside down triangles in order to create a balanced poly throughout the length of the field. The upright triangles smooth out the transition just fine but the upside down triangles show up as pure ditches with no gradual transition.

I've ensured that the coordinates for each vertex attached to the adjacent triangles are on the same point and there is no overlapping by either the flatten poly used under the field or the surrounding triangles.

If you take a look at the birds eye view screenshot, you'll see that the problem lies with some triangles in the formation while others work fine. The altitudes on all of them are the same (ie, the ones near the field are at the field elevation while the points furthest away have a slightly lower altitude to allow a slope but are uniform in number throughout the length of the runway). See ADE screenshot for how they look in the program.

I'm also attaching the ADE project file for your perusal should you feel the need to tweak something in there to cure my problem. The VEPY project file is the actual airport while VEP1 is just a wider runway I've made separately in order to reflect the full width of the runway construction but the usable width is slightly smaller according to the AIP information.

Thanks again for such a lovely program and the wealth of information that is so pristinely preserved on this forum.
 

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gadgets

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#2
Sloping triangles are the only way to go short of generating your own mesh.

While the job can be done with ADE, it's going to require a lot of work to produce anything that looks at all realistic. You should look, instead to sBuilder(X) or Terrain Sculptor Pro. The latter will make the job a lot easier, but it has a steep learning curve.

Don
 
#3
Sloping triangles are the only way to go short of generating your own mesh.

While the job can be done with ADE, it's going to require a lot of work to produce anything that looks at all realistic. You should look, instead to sBuilder(X) or Terrain Sculptor Pro. The latter will make the job a lot easier, but it has a steep learning curve.

Don
Thanks for responding, Don.
I am aware of other programs that can help achieve a more realistic result but as you can see from my work in the screenshots, I'm not more than an amateur when it comes to scenery creation. To that effect, ADE satisfies my cravings just fine and I've used the recommended sloping triangle polys in ADE, only the ones that are created upright seem to work fine in generating a gradual transition from the field to the land around it while the upside-down triangles seem to have the opposite effect even though the values are identical to the surrounding upright triangles. That's where I'm struggling to understand on what I may be doing incorrectly.
 
#4
Hello:

Your reply to a couple of initial questions might help us to better advise you with this interesting project. :scratchch

1.) Do you plan to integrate this airport into the appallingly unrealistic default local terrain mesh of FSX / P3Dv4, or do you plan to integrate the airport into a more realistic ex: FreeMeshX 30 Meter terrain mesh to be downloaded / utilized by the end user ?

2.) Do you plan to keep the entire navigable airfield including RWYs, Taxiways, Aprons etc., all at (1) assigned Altitude, so that AI traffic can operate normally, or do you instead intend to render the real world terrain slope for the airfield ?

GaryGB
 
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#5
Hello:

Your reply to a couple of initial questions might help us to better advise you with this interesting project. :scratchch

1.) Do you plan to integrate this airport into the appallingly unrealistic (nearly flat !) default local terrain mesh of FSX / P3Dv4, or do you plan to integrate the airport into a more realistic ex: FreeMeshX 30 Meter terrain mesh to be downloaded / utilized by the end user ?

2.) Do you plan to keep the entire navigable airfield including RWYs, Taxiways, Aprons etc., all at (1) assigned Altitude, so that AI traffic can operate normally, or do you instead intend to render the real world terrain slope for the airfield ?

GaryGB
Hi Gary,

Apologies, I should've mentioned such trivial details for you and others to better investigate what I'm working with. I am indeed using FreeMeshX and yes the entire field along with runways, taxiways, aprons, etc are all at the same altitude as the airport reference point (4,646ft). According to the AIP, the field is more or less at a set height while there is a stark difference with the terrain around it due to it being built into the side of a mountain (think airports like Madeira).

So, my goal is to leave the uphill side of the field as is since that has a strong transition from hilly to flat while the area behind the terminal has a more gradual, almost step farming like level of transition to the surrounding terrain which is where my problem remains as evident in the pictures I've attached. I just can't seem to get the upside-down triangles to replicate the transition that upright triangles are able to perform through ADE. This results in deep ditches where the upside triangles are placed in ADE while the upright ones transition the terrain elevation just fine in sim.
 
#6
Hi Karan:

I would first inspect the geometry of the CVX vector data point vertices used to create your Triangulated Irregular Network (aka "TIN") intended to blend the central airport flatten into surrounding terrain via a "sloped flatten" CVX Vector BGL. :pushpin:

VEPY_ADEP4_KK_CVX_bgl.jpg


FYI: Work-flow for the above image: ;)

1.) "VEPY_ADEP4_KK.ad4" file was 'Opened' in ADE, and the project was compiled to BGLs; then:

2.) "VEPY_ADEP4_KK_CVX.bgl" was decompiled with Patrick Germain's CvxExtractor GUI to output ESRI *.SHP files

3.) "FLXVEPY_ADEP4_KK_CVX.shp" was 'Opened' in Global Mapper

a.) The *.SHP GIS data was re-projected to a ("non-warped") UTM Zone 45 Projection / WGS84 Datum format

b.) The *.SHP GIS data was Exported from Global Mapper as a AutoCAD *.DXF file

4.) The AutoCAD *.DXF file Exported from Global Mapper was Imported to Sketchup as a AutoCAD *.DXF file.


Some additional views in Global Mapper:

VEPY_ADEP4_KK_CVX_SHP_GM_3D_30M_GDEM_World_Imagery_WIREFRAME.jpg

VEPY_ADEP4_KK_CVX_SHP_GM_3D_30M_GDEM_World_Imagery.jpg


BTW: Technically, there is a way to import pre-processed 30 Meter ASTER GDEM data into Sketchup in UTM / WGS84 GIS projection, and 3D model the sloped flatten and any required nearby terraces on the surrounding hillsides.

One can then export a Google Earth *.KMZ file, import the *.KMZ 3D model file into Arno's ModelConverterX (aka "MCX"), and finally export as a CVX Vector "Sloped Flatten" BGL type. :idea:


PS: If you also wish to work on this 'sloped flatten' project in SBuilderX version 3.15 with a continuously scroll-able / Zoom-able imagery background, you can "Append" to an empty project, the FLXVEPY_ADEP4_KK_CVX.shp" ESRI *.SHP file output by Patrick Germain's CvxExtractor GUI.

Alternatively, if you also wish to work on this 'sloped flatten' project in SBuilderX version 3.15 with a continuously scroll-able / Zoom-able imagery background, you can "Append" to an empty project, the attached FLXVEPY_ADEP4_KK_CVX.BLN" Surfer *.BLN file that may otherwise be output by Patrick Germain's CvxExtractor GUI.

https://www.fsdeveloper.com/forum/a....44815/?hash=16d766c59329816dfc85a8901ef8bf12

VEPY_ADEP4_KK_CVX_SHP_CVXE_BLN_to_SBuilderXv315.jpg

VEPY_ADEP4_KK_CVX_SHP_CVXE_BLN_to_SBuilderXv315_ESRI_World_Imagery.jpg


NOTE: The tile server for ESRI World Imagery in SBuilderX shows a more fully completed VEPY airfield than imagery on Google or Bing tile servers.

GaryGB
 

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#7
Hi Gary,

Thanks for the exhaustive details you've taken the time to type for my benefit. Looking at your first image, it seems to me that the geometry is indeed uniform so there shouldn't be any errors like the ones I posted via screenshots in the OP.

Your detailed steps will definitely allow me to explore other more advanced software for dealing with such issues but I'm afraid it's beyond my current knowledge level and free time. I was really only hoping to get a rudimentary solution within ADE as that is the only software I've used and since as the triangular patterns worked to a certain extent, I'm inclined to believe there may be something I am doing wrong in ADE itself.

I think the most straightforward method without needing the ability to use several different programs is the "pre-processed 30 Meter ASTER GDEM data into Sketchup in UTM / WGS84 GIS projection, and 3D model the sloped flatten and any required nearby terraces on the surrounding hillsides" method. I may try and explore that further when I have sufficient playtime to really dig my hands into it.

Nevertheless, thank you for all your help! I'll certainly bookmark this and hope to return to the advanced methods you so effortlessly explained when I have a bit more free time and better reference material. Until then, I'll likely only continue experimenting within ADE to see if I can resolve it to a satisfactory level.
 
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