Height of terrain returned invalid

DevSim · Post by **DevSim** » Tue Jan 03, 2012 6:08 am

Dear P3D folks,

What is the correct way to obtain the height of terrain via SimConnect? I am currently using

Code:
hr = SimConnect_AddToDataDefinition( simConnectHandle,
DEFINITION_3,
"GROUND ALTITUDE",
"feet",
SIMCONNECT_DATATYPE_FLOAT64 );

combined with a timed approach. This can't be it, as after repositioning, I am running into issues: I get a Sim Stop and a Sim Start event - but the height returned is invalid.

What is the correct method to get back correct height of terrain values after repositioning over large distances?

Regards,

DevSim

Post by **Beau Hollis** » Thu Jan 05, 2012 8:42 am

Is the screen blacking out and reloading the terrain upon reposition? It should be, as moving large distances puts you out where there could be no terrain or a very low LOD terrain with invalid heights.

Thanks,

Beau

DevSim · Post by **DevSim** » Thu Jan 05, 2012 8:44 am

Hi Beau,

Yes, it is reloading and flickering heavy, building up the scenery on a level by level.

Regards,

DevSim

Post by **Beau Hollis** » Thu Jan 05, 2012 10:28 am

Interesting. I was thinking it would bring up the loading bar and black out the screen. (which is what happens when you use the map to move the aircraft more than a certain threshold away from it's current location). I thought setting the aircraft location via simconnect had the same effect.

You might also try using SimConnect_RequestDataOnSimObject call with PLANE_ALT_AG to get ownship height above terrain. I came across some info from a user in an old ticket when searching to see if this was a known bug. Note that if you have set SIM_DISABLED, the height above terrain will not be valid outside the starting area.

Beau

DevSim · Post by **DevSim** » Thu Jan 05, 2012 10:31 am

Thanks Beau,

I must say I run with the externalsim registered method and in full freeze mode.

I can and will try PLANE_ALT_GT but feel strongly, that the height will be invalid too. A quick workaround is to sit and wait some more time after a reposition - but loading time is non deterministic and it fore sure isn't valid after I receive the new sim start event (which I have tested).

Regards,

DevSim