Ok this is really killing me. I can't find a direct answer anywhere, is this such a rare thing to look for?

Best I could find is: this and this. :?


What I need to know is how do I plot on an orthographic map of the 'real' shortest movement from one point to another on the surface of a sphere in the form of a simple 2D vector?

I imagine that I'll need an equation that takes the current point, the destination point, the radius of the earth and speed to provide me with a pair of 2D VelX and VelY values. So I guess 2 equations then.

Anyone know how to do this?

I should be able to create results similar to something like this...