Could you be more specific about what you want?

If you just want a nice curve, I suggest making a simple four-control-point Bezier spline. If you have latitude and longitude for both locations, then the points on the bezier curve will be easy to calculate. The first and last will be NY & Madrid, while the second and third points will be directly above those cities by some amount. This is super-easy to calculate because the high point will simply be a scaled version of the low one, relative to the "earth marble"

You can then rotate the spline according to the same coordinates as the rest of the earth model.

If you want animating motion, just follow the Bezier formula along the curve.


kb, Trion Worlds

Our problem is about draw the aircraft. We are using a file .obj and it's burn down a lot of procesor. Any suggestion about that? Thank you very much

just use a sphere. that way you don't have to worry about the orientation of the object.

or, if you need to show orientation, just draw an arrow. three lines.

Or a sprite with a picture of an aircraft, e.g.

Two triangles, or five edges.

kb, Trion Worlds

I want to represent an aircraft spinning over the earth, like a flight. Is it that so harder? Thanks

Yes, perhaps try a submarine.

Seriously, arcs along a sphere are kind of funny,
take a look at this page,

http://en.wikipedia.org/wiki/Spherical_coordinate_system

it'll educate you on how to navigate a sphere.
Your airplane is basically just a location on a sphere, with a certain azimuth and inclination, only this sphere is of variable diameter, the difference of which is its height above the earth surface.

>> Our problem is about draw the aircraft. We are using a file .obj and it's burn down a lot of procesor.

Is that your problem or not?

Answer: use a simpler model.

>> I want to represent an aircraft spinning over the earth, like a flight. Is it that so harder?

Answer: use a simpler model.

kb, http://www.riftgame.com/

You may use the ijeomamotion library and a 3D tween:

TweenPath3D_Complex example applet



dw