Geodetic (lon/lat in radians, height in meters above the ellipsoid) to ECEF.
Defaults to the WGS84 (Earth) ellipsoid; pass a/b to convert on another body —
e.g. the Moon's sphere (a = b = 1,737,400) for Cesium Moon Terrain region bounds,
interpreted in that body's own fixed frame. For a sphere (a == b) the eccentricity is
0, so this reduces to the plain spherical mapping.
Geodetic (lon/lat in radians, height in meters above the ellipsoid) to ECEF. Defaults to the WGS84 (Earth) ellipsoid; pass
a/bto convert on another body — e.g. the Moon's sphere (a = b = 1,737,400) for Cesium Moon Terrainregionbounds, interpreted in that body's own fixed frame. For a sphere (a == b) the eccentricity is 0, so this reduces to the plain spherical mapping.