Angles in 3D

Direction in 2D is a single angle - heading

X/Y plane		X/Z plane
`x = cos(heading) y = sin(heading)`		`x = cos(heading) z = -sin(heading)`

Direction in 3D can be described by 2 angles - heading & pitch

    x = cos(heading) * cos(pitch)
    y = sin(pitch)
    z = -sin(heading) * cos(pitch)