A simple thing to remember is that the camera has a position numerical and so do objects with "centre" so if you copy this data from one to the other, the objects will be in the same place as the camera. If you move the camera slightly or create another camera to move, then you will see the objects fully to manipulate them. Object bounding boxes show up even if the objects end up being hidden by land surface. Also remember that Y is altitude only if you stick around the default coordinates 0,0,0 because we have a whole planet and it doesn't use distance from surface coordinates but X,Y,Z. Ideally we'd want things like distance from land surface, altitude from sea level and latitude,longitude but the program is usable without these. If you move far from the 0,0,0 coordinates then you run into other problems with objects or heightfields being out out of rotation from the planet surface. There are some other issues here that I will post another thread about.