1. A concise explanation of the problem you're experiencing.
I have the quaternion representing an entity's orientation from the ECEF frame to the body frame (e.g. body frame for an aircraft: +x is out of nose, +y is out of starboard wing, +z is down). I also have the entity's ECEF position.
How do I assign the quaternion and tell it that it is ECEF to body? It seems like all options require a heading/pitch/roll or a local NED/ENU frame.
2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.
var position_ecef = new Cesium.Cartesian3(ecef_x, ecef_y, ecef_z);
var orientation_ecef_to_body = new Cesium.quaternion(qx, qy, qz, qw);
How do I specify that the orientation is ECEF to body? Or do I have to convert my quaternion to something else first?