Rotate ----> Left Mouse / Left Mouse + Shift
Pan ----> Middle Mouse / Left Mouse + Ctrl
Zoom ----> Right Mouse / Left Mouse + Alt / Mouse Wheel
Reset view ----> <r> key

The 3D image to the left is a surface rendering of the embryo model currently in the viewer.
The position of the green disc represents the section through the embryo model that is displayed in the main window.
Any arbitrary section may be selected using the rotation and distance controls.
The 3D scene can be manipulated using mouse and keyboard keys.

3D (x3dom) Controls

Navigation mode selection
- Examine (default) ----> <e> key
- Walk ----> <w> key
- Fly ----> <f> key
- Look at ----> <l> key
Viewpoint selection
- Reset to default ----> <r> key
- Next ----> <Page Down> key
- Previous ----> <Page Up> key
- See all ----> <a> key
- Upright ----> <u> key
Set centre of rotation ----> double click Left Mouse
Toggle debug info. ----> <d> key

The only useful navigation mode for this application is the (default) Examine mode.
Using the <r> key to reset the viewpoint does NOT reset the centre of rotation if this has been changed.
If all else fails, re-load the page!