Airport terminal on a small hill

[seippg]

No progress on this part today other than a lot of learning. I may just work on other stuff and come back to it.

 

[GaryGB]

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/#post-771174

Yeah, I had just started that. The good news is that, when I delete my scenery from P3D, everything goes flat again so it's in my scenery...like you said...somewhere. As I just started on this part today, there's not much lost to re-get the stock airport and start over.

EDIT: I fixed it by deleting the .cvx file ADE had made. Apparently, it stopped making new ones when I was changing the polys. Maybe that compiler was being messed up by the polys. In any case, things are flat again and I'm not sure I want to try that road again.

Since the elevation difference between the lowest point on the Apron SE of the Jetway building and concourse walkway is only around 5 Feet, it may be more practical to simply extend the 1-Altitiude / 1-piece 'central' airport flatten polygon up to the edge of the foundation for the terminal building and therefore also the edge of the hillside, so that the flatten "cuts off" any terrain mesh loaded by the end user.

Also, when the 3D model of the terminal is placed in position, it will be done at 0-Meters / Feet AGL, so it will always sit at ground level on top of any terrain mesh loaded by the end user.


You may wish to open in FSX / P3D SDK TMFViewer, this file (or its equivalent in the version of P3D you have installed):

[P3D install path]\Scenery\0302\scenery\dem0302.bgl

Then, to see what LODs are in this local default terrain mesh BGL:

TMFViewer Menu > View > Level of Detail > All


I can offer further suggestions as to how to implement the flatten where it meets the hillside under the terminal building pending your reply listing the LODs present within the above dem0302.bgl.

GaryGB

 

[seippg]

I can offer further suggestions as to how to implement the flatten where it meets the hillside under the terminal building pending your reply listing the LODs present within the above dem0302.bgl.

The LODs are 0 through 10...so 11 in all. I'm curious about this idea even if I don't quite understand it. If it works it would simplify much.

One other issue I'm going to have. If you look at that photo up there, there's a loading dock that sinks at a straight angle down into the ground below the tarmac by about five feet so, not only do I need to raise a hill, I need to make a hole. If I make a generic kind of hole I can clean it up with 3D objects in Blender by hiding it but, my guess is that a generic hole will bleed into the airport flatten. No vehicles or aircraft go over there so, maybe that's okay? I can't see where the airport flatten is over there but, judging by the shape of it in TMFViewer, it looked like it covered all of the ramp and, perhaps, part of the terminal.

Gregg

 

[GaryGB]

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771206

I can offer further suggestions as to how to implement the flatten where it meets the hillside under the terminal building pending your reply listing the LODs present within the above dem0302.bgl.

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771208

The LODs are 0 through 10...so 11 in all. I'm curious about this idea even if I don't quite understand it. If it works it would simplify much.

So much for rumors LM upgraded terrain mesh for P3D beyond what ACES provided in FSX / ESP !

That means you would only have a low-resolution 'hill' (if any ! ) in FS / P3D when the terrain in FS default dem0302.bgl is rendered by the KILM terminal, and there would potentially only be a terrain grid vertex available very 38.2 Meters apart on the ground.


And unless you can convince your end users to set their FS GUI Terrain Mesh sliders at 100 % on the Terrain Mesh complexity slider and ex: 1.0 Meter (not 10.0 Meter) on the Terrain Mesh Resolution slider to force FS to provide interpolated 'artificial' terrain grid vertices in the sub-system of the FS scene at run time, there would also not be a proper render of any highly-detailed CVX vector sloped flatten you might use to create the hillside and any sloped ramps etc.


So, IMHO, it would be best to make most of those ramp, retaining wall, terminal building foundation and 'sloped' loading / receiving dock details ...as a textured 3D model, with an accompanying carefully-abutted sloped flatten for other nearby terrain that underlies / projects into the base of the terminal building, which also precisely aligns edges of all its triangles to meet the edge of the 'central' airport flatten polygon.

The CVX vector sloped flatten will be rendered as a modified terrain mesh that is capable of displaying the draped custom photo-real land class made via SBuilderX and compiled to BGL by FS SDK Resample, with the option of having seasonal changes and (custom) autogen as well.

You may also need to make a custom terrain mesh; I'll post some links to USGS 10 Meter DEMs a little later.


GaryGB

 

[seippg]

You may also need to make a custom terrain mesh

Yeah, I was worried that, given people's different mesh settings, I might not be able to use custom mesh other than to move it out of the way (e.g. the loading dock). Do you think I'll need to make a custom flatten?

 

[GaryGB]

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771218

Yeah, I was worried that, given people's different mesh settings, I might not be able to use custom mesh other than to move it out of the way (e.g. the loading dock). Do you think I'll need to make a custom flatten?

Yes, but I would first see what a custom terrain mesh BGL will provide you with, as far as a reasonable rendition of the "hill", as well as supplying some 'built-in' ground elevation data points, which will be required to make a sloped flatten in either SBuilderX or ADE, and/or via MCX as a derived 3D model data sub-set.


You may wish to download / open in QGIS, this 10 Meter DEM source data to re-project and convert to a gridded elevation GeoTIFF:

KILM terminal and surrounding area ...(from: https://viewer.nationalmap.gov/basic/#productSearch) :

USGS NED ned19_n34x50_w078x00_nc_statewide_2003 1/9 arc-second 2012 15 x 15 minute IMG
Published Date: 2012-01-01
Metadata Updated: 2017-01-27
Format: IMG (204.66 MB),Extent: 15 x 15 minute

https://prd-tnm.s3.amazonaws.com/St...MG/ned19_n34x50_w078x00_nc_statewide_2003.zip


USGS NED ned19_n34x25_w078x00_nc_statewide_2003 1/9 arc-second 2012 15 x 15 minute IMG
Published Date: 2012-01-01
Metadata Updated: 2017-01-27
Format: IMG (121.78 MB),Extent: 15 x 15 minute

https://prd-tnm.s3.amazonaws.com/St...MG/ned19_n34x25_w078x00_nc_statewide_2003.zip


Note that these are packaged in "ERDAS Imagine" *.IMG GIS file format, and should first be extracted from the ZIP folder before opening the IMG file(s) in QGIS.


A general overview of the proposed work-flow:

After the IMG files are opened in QGIS, they must be re-projected to Geographic (Lat-Lon) projection / WGS84 datum as required by the FSX / P3D SDK.

In QGIS, one will select the area(s) of interest and export a 1-piece 3D elevation data format 32-Bit raster GeoTIFF file.

Next, one will output a INF file using GeoTIFF-To-INF (which will need to be edited so that the GeoTIFF can be processed to make terrain mesh rather than an aerial imagery BGL).


The GeoTIFF will then be submitted to FSX / P3D SDK Resample along with the edited INF to process the "raster elevation format" GeoTIFF to create a custom terrain mesh BGL with a 9.6 (aka "10") Meter / LOD-12 resolution.


Feel free to inquire further if you are inclined to proceed with making the recommended custom terrain mesh, as well as the sloped CVX vector flatten derived from a portion of a custom-made 3D model of the terminal building and its adjacent foundation / terrain 'skirt'.


PS: Some info on opening IMG files in QGIS:

https://docs.qgis.org/2.2/en/docs/user_manual/introduction/getting_started.html


Info on QGIS export raster file format process: (this example shows ASC output rather than TIF / GeoTIFF)

http://wiki.tuflow.com/index.php?title=QGIS_Export_Raster_to_asc


GaryGB

 

[seippg]

Thanks Gary. I'll see if I can figure it out.

 

[seippg]

In QGIS, one will select the area(s) of interest and export a 1-piece 3D elevation data format 32-Bit raster GeoTIFF file.

Next, one will output a INF file using GeoTIFF-To-INF (which will need to be edited so that the GeoTIFF can be processed to make terrain mesh rather than an aerial imagery BGL).

I did find the airport on one of the files in QGIS. I clipped the file down to an area right around the airport and then converted to WGS84 EPSG:3857. I then tried to get an INF with GeoTIFF-to-INF but it told me it wasn't in WGS84 projection. I did verify that the file is, in fact, WGS84. I used the same projection conversion I did with the photoreal. Help?

Gregg

EDIT: I tried GeoTIFF-to-INF again and noticed that, before I click 'Save Resample INF', the Lat/Longs were completely off...large numbers up in the millions. I resaved the file using EPSG 4326 WGS84 and used that file for the INF and it worked. Working on the resample.

 

[seippg]

Hi Gary,

Your instructions were spot on. I successfully created a custom elevation BGL. The results...hmmm...

IRL, the hill is fairly smooth. At 1, 2, and 5 meters mesh settings in P3D, it's fairly bumpy. Images below. I also included the TIF, INF and BGL in the zip file below.

1 meter, looking at the loading dock...

2 meter, at the edge of the ramp, looking at the terminal...

https://www.dropbox.com/s/4w59twiuui1jnnt/KILM.zip?dl=0

 

[GaryGB]

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771447

I did find the airport on one of the files in QGIS. I clipped the file down to an area right around the airport and then converted to WGS84 EPSG:3857. I then tried to get an INF with GeoTIFF-to-INF but it told me it wasn't in WGS84 projection. I did verify that the file is, in fact, WGS84. I used the same projection conversion I did with the photoreal. Help?

Gregg

EDIT: I tried GeoTIFF-to-INF again and noticed that, before I click 'Save Resample INF', the Lat/Longs were completely off...large numbers up in the millions. I re-saved the file using EPSG 4326 WGS84 and used that file for the INF and it worked. Working on the resample.

Online web map and tile servers, and SBuilderX' Background Map displays and/or works with GIS data sets in a 'non-warped' GIS projection format:

"Spherical Web Mercator" (aka "EPSG:3857")

https://en.wikipedia.org/wiki/Web_Mercator


Because FS' run time rendering engine dynamically 'warps' vector and raster terrain scenery content to fit the variable terrain tile shape / size on ground relative to terrain grid quad corner vertices, we store data in BGLs in a certain way, requiring us to submit that data to the FS SDK terrain compilers in:

Geographic (Lat-Lon) projection / WGS84 datum (aka "EPSG:4326")

https://nsidc.org/data/atlas/epsg_4326.html


NOTE: EPSG is an international reference standard published by "European Petroleum Survey Group" to describe GIS projection / datum formats

https://translate.google.com/transl...an_Petroleum_Survey_Group_Geodesy&prev=search



Use of GeoTIFF-To_INF with GeoTIFFs is for a convenient way to write out the Geo-referencing info for GIS data within the GeoTIFF file format ...provided that the GeoTIFF is already formatted with the projection and/or datum required by the FS / P3D SDK.

If GeoTIFF-To_INF reads a GeoTIFF source file 'intended' for use with the FS / P3D Terrain SDK as not being formatted with the projection and/or datum required by the FS / P3D Terrain SDK, it will throw the errors you have seen.

GaryGB

 

[GaryGB]

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771459

Hi Gary,

Your instructions were spot on. I successfully created a custom elevation BGL. The results...hmmm...

IRL, the hill is fairly smooth. At 1, 2, and 5 meters mesh settings in P3D, it's fairly bumpy. Images below. I also included the TIF, INF and BGL below.

1 meter, looking at the loading dock...

http://i.imgur.com/QvErtn9.jpg


2 meter, at the edge of the ramp, looking at the terminal...

http://i.imgur.com/YQVdcgS.jpg


https://www.dropbox.com/s/q94sn08piaff8mk/ElevationDataSmallWGS84-EPSG4326.bgl?dl=0

https://www.dropbox.com/s/kcnp52b5b61jm37/ElevationDataSmallWGS84-EPSG4326.inf?dl=0

https://www.dropbox.com/s/r0lpjlxnl9hiv2v/ElevationDataSmallWGS84.tif?dl=0

Congratulations on your further progress !


Downloading the above linked files now...

UPDATE:

I was able to open the INF file, but the other 2 files (TIF and BGL) will not open in P3Dv1.4x SDK TMFViewer, and the GeoTIFF will not open in either a GIS application or a graphics application.


Could you please instead package those files inside ZIP files and edit new download links into your post above:

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771459

...to help rule out 'alteration' of those BGL and TIF files by DropBox and/or elsewhere over the internet ?


PS: I shall temporarily defer addressing issues with 'terrain terracing' seen in your screenshots above, pending access / download / evaluation of replacement files for the above problematic GeoTIFF elevation data format TIF, and BGL files.

GaryGB

 

[seippg]

I was able to open the INF file, but the other 2 files (TIF and BGL) will not open in P3Dv1.4x SDK TMFViewer, and the GeoTIFF will not open in either a GIS application or a graphics application.


Could you please instead package those files inside ZIP files and edit new download links into your post above:

Done.

 

[GaryGB]

Done.

OK ... Downloading the above linked files now...

UPDATE:

Files inside the above linked ZIP are now able to be opened / processed normally as tested thus far.

GaryGB

 

[GaryGB]

I suggest that you modify a copy your INF file by opening it in NotePad or NotePad++, then replacing its contents with the following text:

[Source]
Type=GeoTIFF
Layer=Elevation
SourceDir="."
SourceFile="ElevationDataSmallWGS84-EPSG4326.tif"
PixelIsPoint=1
ulxMap=-77.9245987654321
ulyMap=34.2939814806028
xDim=3.38995430355807E-05
yDim=2.80135860649571E-05

[Destination]
DestDir="."
DestBaseFileName="ElevationDataSmallWGS84-EPSG4326"
DestFileType=BGL
LOD=3,Auto
FractionBits=3

When you submit the above cited source GeoTIFF with the above edited INF file, you should end up compiling a new terrain mesh BGL which has effectively eliminated the "terracing".


As previously mentioned above, your "central airport background / boundary flatten" will likely 'cut off' the adjacent 'elevated' hillside at the edge of its polygon vertices under / near the KILM terminal building and linear retaining wall(s), leaving a straight vertical face.


You may also wish to add a sloped CVX vector flatten 'terrain skirt' in any areas which surround and directly meet vertices of your "central airport background / boundary flatten".


Additionally, in addition to 3D models for the foundation of the terminal building and loading / receiving dock, you may wish to create textured 3D models of retaining walls which overlie (and thereby 'conceal') the edge of your "central airport background / boundary flatten" and the hillside or other airport "paved ground" edges where appropriate.


Hope this helps a bit more.

GaryGB

 

[seippg]

Wow, that's much nicer, even with 5 meters. This is good. I think I need to exclude the airport flatten on the road out front or make a custom flatten to get the stock flatten out of the road right at the front of the building. Also, stock flatten is well above this custom mesh over by the runway...a steep wall. Overall, I like it, though, I have to see how it lines up with my terminal and see how to blend it

 

[GaryGB]

Here's some screenshots of the 'alignment' in a Global Mapper GIS application "3D mode" preview of a texture mapped aerial image from ESRI ArcGIS World Imagery draped onto the 10 Meter elevation data format GeoTIFF you output from QGIS:

GaryGB

 

[seippg]

Here's some screenshots of the 'alignment' in a Global Mapper GIS application "3D mode" preview of a texture mapped aerial image from ESRI ArcGIS World Imagery draped onto the 10 Meter elevation data format GeoTIFF you output from QGIS:

That road looks about perfect. I wonder if QGIS can do that. I think I'm going to have to do some work around the retaining wall.

 

[GaryGB]

Notice a visible mis-alignment of aerial imagery with the underlying terrain mesh in my screenshots above.

http://www.fsdeveloper.com/forum/threads/airport-terminal-on-a-small-hill.440002/page-2#post-771489


Compare the above images with Google Earth Desktop 3D mode:

IMHO, you should now confirm Geo-referencing of your GeoTIFF elevation data with alignment of your custom aerial imagery BGL in FS.

The alignment of both those layers and BGLs should match precisely when displayed in FS at run time.

I would recommend a re-compile of the terrain mesh using your GeoTIFF elevation data and the INF above with this edit:

[Source]
Type=GeoTIFF
Layer=Elevation
SourceDir="."
SourceFile="ElevationDataSmallWGS84-EPSG4326.tif"
PixelIsPoint=1

[Destination]
DestDir="."
DestBaseFileName="ElevationDataSmallWGS84-EPSG4326"
DestFileType=BGL
LOD=3,Auto
FractionBits=3

You may note I have purposely removed the Geo-referencing inserted when the INF was made by GeoTIFF-To-INF


FYI: FS / P3D SDK Resample will automatically read the Geo-referencing information within the GeoTIFF and its accompanying *.TFW file, because we have used the "Type"=GeoTIFF" source parameter value for your INF file.

However, IIRC, if we leave the 'explicit' source parameter values for ulxMap, ulyMap, xDim, yDim within the INF when submitted to FS / P3D SDK Resample, it 'may' over-ride the otherwise automatic reading of Geo-referencing information within the GeoTIFF and its accompanying *.TFW file.


I would recommend reading the Metadata in QGIS for the source GeoTIFF and using it in your INF without truncating any numerals from the full extent of decimal places, as a comparison with that output by GeoTIFF-To-INF, to see if a better alignment might be achieved between the terrain mesh and the aerial imagery.

GaryGB

 

[GaryGB]

"Bumped" for edits to my latter post immediately above.

GaryGB

 

[seippg]

I would recommend reading the Metadata in QGIS for the source GeoTIFF and using it in your INF without truncating any numerals from the full extent of decimal places, as a comparison with that output by GeoTIFF-To-INF, to see if a better alignment might be achieved between the terrain mesh and the aerial imagery.

Okay, did that. I still see misalignment. I think the problem could be in the photo bgl. The conversion I did was to EPSG:3857, not EPSG:4326. I did the elevation in 4326. Perhaps I should reproject the photo image to 4326 as well and feed it to resample.exe?