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Cliifs on airports

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Cliifs on airports

Postby legoboyvdlp » Sun May 19, 2019 5:43 pm

Hi,
does anyone know how to remove these cliffs?

D-ECHO has been generating the GCLP airport for me. However, the airport has very steep cliffs.
This elevation difference is consistent with real life - the road is elevated above the airport.

However, there should be a smooth curve down rather than very steep cliffs like this.
Image


Does anyone know if there is a setting that will reduce these cliffs?
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Re: Cliifs on airports

Postby xDraconian » Sun May 19, 2019 10:28 pm

Try adjusting the max-slope setting. If you don't specify a max-slope then TG assumes you want perfectly flat airport terrain. This generates the cliffs or plateau that you see along the airport boundary resulting from joining the flat airport surface to the surrounding irregular surface terrain.

Keep max-slope values small. A typical glideslope is 3-degrees, so runway slope above 2-degrees is very unusual.
Typical: < 1-degree
Rare: 1-degree to 2-degrees
Very unlikely: > 2-degrees

e.g. genapts850 --max-slope=1.0
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Re: Cliifs on airports

Postby D-ECHO » Mon May 20, 2019 1:18 pm

Hi xDraconian, are you sure about the unit? At least my genapts850 states "[--max-slope=<decimal>]" instead of <deg>?
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Re: Cliifs on airports

Postby legoboyvdlp » Mon May 20, 2019 3:06 pm

Unless that means decimal degrees as in 1.000 or 1.535?

Edit: checking the source code shows it indeed is decimal:

Code: Select all
double slope = (p2.getElevationM() - p1.getElevationM()) / dist;

p1.setElevationM( p2.getElevationM() - (dist * slope_max) );
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Re: Cliifs on airports

Postby wkitty42 » Mon May 20, 2019 4:47 pm

xDraconian wrote in Sun May 19, 2019 10:28 pm:Keep max-slope values small. A typical glideslope is 3-degrees, so runway slope above 2-degrees is very unusual.

have you seen the airport on the other side of the mountains from PHNL? the old military base? Bellows Airfield XBEL... there's one old runway there that goes up at a pretty large angle from inland to the sea... of course, they're not all used any more since it is closed but it is still there in FG...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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