Q:

Finding the centre point of the visible parts in the Autodesk Viewer

Excuse the vagueness of this question, but in a model in the viewer, I'd like to know how I can establish the centre point of the visible parts.   When I call fit-to-view on a model with hidden parts, I can see a dot appear in the viewer which seems to represent exactly this - the centre of the visible parts - how can I retrieve the coordinates of this point in code? 

A:

The little green dot represents the "target" of the camera.  You can get its coordinates using viewer.navigation.getTarget().