Outerra forum

Anteworld - Outerra Game => Tech demo, support, updates => Topic started by: zzz on March 26, 2014, 07:03:49 am

Title: What value is gravity set at as a function of altitude?
Post by: zzz on March 26, 2014, 07:03:49 am

I need to created an FDM file that counteracts the forces of gravity but need to know the precise value of gravity at all altitudes. What does Outerra have it set as in its property tree? Thks.

Title: Re: What value is gravity set at as a function of altitude?
Post by: cameni on March 26, 2014, 08:01:47 am

Property tree? Gravity is computed by JSBSim, we are only giving it the mean Earth radius we are using (R=6378135m).

For vehicles the gravity is computed as:

Code: [Select]

    gravity = 9.80665 * R² / (R+h)²;

I guess it should be the same in JSBSim, since it's the standard way.

Title: Re: What value is gravity set at as a function of altitude?
Post by: zzz on March 28, 2014, 03:31:00 pm

Thanks, that answered that.

But now there's a new problem. Someone designed an anti-gravity engine for me in FlightGear. I've tried transplanting the JSBsim files into Outerra but it gives me errors.

http://target4today.com/_t4t-aircraft_/T4T-Hyperion.zip (http://target4today.com/_t4t-aircraft_/T4T-Hyperion.zip)

I'm using the standard mig29 setup except its content is replaced with the FDM file. I kept the engine info as Outerra crashes if nothing's in the <propulsion> field.

<system file = "anti-gravity"/> is the first thing it doesn't like. I've put the AG systems in the Outerra systems install directory and also created a systems directory in the ship package. No dice.

Title: Re: What value is gravity set at as a function of altitude?
Post by: cameni on March 28, 2014, 03:55:56 pm

When it was added? Maybe we have an old version there ...

Title: Re: What value is gravity set at as a function of altitude?
Post by: zzz on March 28, 2014, 04:12:29 pm

it used flightgear v3.1. I tested it in that and it worked.

Title: Re: What value is gravity set at as a function of altitude?
Post by: zzz on April 02, 2014, 10:23:46 am

Any update on this? Also works in FG v3.0.0

Title: Re: What value is gravity set at as a function of altitude?
Post by: cameni on April 02, 2014, 12:12:53 pm

Angrypig says our version came from before FG 3.0, September 2013
Time to update it ...