P3D v5 Sloped Airport Taxiway Creation

scruffyduck

Administrator
Staff member
FSDevConf team
Resource contributor
I have been reminded that creating a taxiway using the normal methods will give each new taxi point and altitude of zero at the moment. The altitude of a taxi point is not relevant and ignored if the airport is not sloped or created for earlier sim versions. This altitude is AMSL - there is no IsAgl flag available.

The question for me is what altitude value to put into a new taxi point when it is created. I assume that the user will need to manually intervene to set points to suit their sloped design. So does it matter they are zero - generally that could be used as a flag to indicate an unset point altitude. The color of the node might be made say red. There is a small risk that someone will want a taxi way at zero.

An alternative is to set the altitude at the Airport reference altitude
Another would be to take the altitude of the previously created taxi point and use that.
Or...…

I would appreciate some views. Of course if you never plan to create a sloped airport then this need not affect or concern you. For example you are creating for FS9 > P3Dv4
 

gadgets

Resource contributor
Presumably, these elevations are absolute, not AGL. If so, you can't use "0" as a flag. There are a few places in the world below sea level so "0" is a valid setting. I'd be inclined to use ARP elevation as default.
 
for sloped airports I would suggest using the altitude of the last taxipoint. This is imo the best way for a fast way off adding new taxiways/taxipaths without changing them later on. You only need to set the new altitude for the first point and then you can darw the next points without editing them again.
 
for sloped airports I would suggest using the altitude of the last taxipoint. This is imo the best way for a fast way off adding new taxiways/taxipaths without changing them later on. You only need to set the new altitude for the first point and then you can darw the next points without editing them again.
Why would you want to do it that way? Just look at the airport charts. Most have at least the altitude of all touch down lines. from there interpolate the rest. Thats how I did it.
 
Why would you want to do it that way? Just look at the airport charts. Most have at least the altitude of all touch down lines. from there interpolate the rest. Thats how I did it.
The way i wrote about was not for the runways, more for taxiways. For example EDDH has the Lufthansa area about 2-3 meters above the rest of the airport. So when drawing a taxiway there i have to edit each node
 
The way i wrote about was not for the runways, more for taxiways. For example EDDH has the Lufthansa area about 2-3 meters above the rest of the airport. So when drawing a taxiway there i have to edit each node
I think I understand you're thinking. Interesting approach.
What i did was to do the runway elevations 1st. Then use the taxi to runway entry points to figure out taxi way elevations, and reverse engineer it from their.
But i also know my airport well as to where the elevations changes are. Still took a lot of trial and error to get in the way I wanted it.
 

scruffyduck

Administrator
Staff member
FSDevConf team
Resource contributor
It is always going to be likely to need to edit. What is best - a consistent and reasonably close value that needs tweaking or something that is clearly broken and say - set me please?

It is still early days on creating sloped airports and I guess it could become quite popular
 
I think I understand you're thinking. Interesting approach.
What i did was to do the runway elevations 1st. Then use the taxi to runway entry points to figure out taxi way elevations, and reverse engineer it from their.
But i also know my airport well as to where the elevations changes are. Still took a lot of trial and error to get in the way I wanted it.
You mentioned that you use the "airport charts" for the altitude of the touchdown lines. Sorry to ask a stupid question, where could I go to find such "airport charts" as I would like to further experiment with sloping for runways (first..to get my feet wet) and then for taxiways...
 
You mentioned that you use the "airport charts" for the altitude of the touchdown lines. Sorry to ask a stupid question, where could I go to find such "airport charts" as I would like to further experiment with sloping for runways (first..to get my feet wet) and then for taxiways...
I just google it. It should be easy to access on the Internet.
Airnav.com Should help you a lot as well.
You are looking for the AERODROME CHART. What airport are you thinking of?

The chart should look something like the one below.
1588338966364.png
 
I've made some trial as well on sloped airport.
On a large airport, slope conversion is a hudge manual work to adjust everything to suit a local mesh.

So I'm thinking about a workflow I'm currently experiment:
  • Import local airport mesh in QGIS
  • Export an elevation profil points list (CSV format) computed from a "digitized line" manually drawn along runways & taxiways [QGIS qProf plugin]
  • Open original BGL airport in ADE, convert to sloped property, export its XML
  • Process both XML and CSV to adjust automatically altitudes to all TaxiPoint from nearest mesh point available (I have programmed yesterday a small utility to do this)
  • Re-import the new XML in ADE, switch runway taxilink to FLATTEN and compile
The principle works fine, but my current problem is that I have no access to the 4.75 meter local mesh of the scenery, but only the standard 38 meters, so it's somehow innacurate on some parts.
I tried to use bgldec to extract the 4.75 m mesh, but I have no idea on how to import BMP's in QGIS :rolleyes:

Then there is the Appron problem as they have only a single altitude value (centered ?) and cannot fit mesh profile.

@scruffyduck : would it be possible to add a mouse "lasso" type selection tool in ADE? It would be a great help :)
 
Last edited:
@scruffyduck
I'm thinking also to an new ADE option that would be really helpfull as well: Add a property to APPRON so that all taxypoints covered by the appron area would take automatically the same altitude. Do you think it's possible?
 

scruffyduck

Administrator
Staff member
FSDevConf team
Resource contributor
@scruffyduck
I'm thinking also to an new ADE option that would be really helpfull as well: Add a property to APPRON so that all taxypoints covered by the appron area would take automatically the same altitude. Do you think it's possible?
I suspect we can do something like that but I am still learning a lot so it might be a little while
 

tgibson

Resource contributor
To select multiple objects, hold down the R key, press and hold the left mouse button, and draw a rectangle with the mouse.
 
Top