eyeOffset
Gets or sets the 3D Cartesian offset applied to this billboard in eye coordinates. Eye coordinates is a left-handed coordinate system, where x points towards the viewer's right, y points up, and z points into the screen. Eye coordinates use the same scale as world and model coordinates, which is typically meters.
An eye offset is commonly used to arrange multiple billboards or objects at the same position, e.g., to arrange a billboard above its corresponding 3D model.
Below, the billboard is positioned at the center of the Earth but an eye offset makes it always appear on top of the Earth regardless of the viewer's or Earth's orientation.