Cesium For Unity
Convert WGS84 to Earth Centered Earth Fixed
csharp
var longitude = 121d;
var latitude = 37d;
var height = 0d;
double3 d3 = GameObject.Find("CesiumGeoreference").GetComponent<CesiumGeoreference>().TransformEarthCenteredEarthFixedPositionToUnity(CesiumWgs84Ellipsoid.LongitudeLatitudeHeightToEarthCenteredEarthFixed(new double3(longitude, latitude, height)));
Vector3 position = new Vector3((float)d3.x, (float)d3.y, (float)d3.z);