Use modifier keys to rotate, pan and zoom when dragging a 3D graphic.
3D Rotate...
Mouse down near the center of a 3D graphic and drag to rotate it in 3D. The 
cursor indicates 3D rotation:
2D Rotate...
Mouse down near the edge of a 3D graphic and drag to rotate it in the plane of the screen. The 
cursor indicates 2D rotation:
Pan...
Press 
while dragging to pan. The 
cursor indicates panning:
Zoom...
Notes
If you change the view of a Graphics3D output and then edit and reevaluate the input, the new output assumes the view of the old output:
while dragging to pan:
while dragging to zoom. Drag upward to zoom in and downward to zoom out: