Re: [Flightgear-devel] Object placement in flightgear scenery

[<Wol...@t-...>]

Curt wrote:

>   OBJECT_STATIC <model_name> <lon> <lat> <alt> <heading>

Good, it works!
Thanks to Normans post of a few days/weeks ago, I can generate lon lat
alt. How is heading defined and how do I calculate it?

Here are some ideas, please tell me whether I am on the right track:

Heading is the angle between "forward" (if, for example we are
speaking about a red fire truck :-)) and north.

I can easily caluculate the x,y,z coordinates in "tile space"
(the coord. sys. that the vertices of this tile are in).
I can calculate them for lets say the centre of the truck and a vertex
in the front. Lets call the vector from the vertex to the front A.
Lets project it onto the horizontal plane, that means take away any
component of A that points in the direction of the vector that is
specified in the gbs of the tile. Lets call this projected vector AP.=20

Take the vector (0,0,1) as a "sort of north" and project it onto the
plane and call it ZP. The Heading is the angle between AP and ZP, as
seen from above, that means as seen from the +gbs vector.

Am I making sense?

BTW, Curt, don't you want to add pitch and roll? That would be very
helpful. People who don't need it can just set it o zero.

>Regards,
>
>Curt.

Bye bye,
Wolfram.