This page is designed for being used with the Browser's Java Implementation

After the Viewer has loaded the file you can use the mouse to control the view. Dragging the mouse means moving the mouse with a pressed button.

Dragging the mouse when pressing the left mouse button (and no moduifier keys) rotates the model. While rotating a circle is shown. This circle shows the extents of a virtual trackball. Dragging inside the circle rotates the model like rotating the trackball. Dragging outside rotates the model around the view axis.
Dragging the mouse with the middle mouse button pressed (or with the shift key and the left mouse button pressed) moves the model in the given direction. Because the point of rotation is always in the middle of the view window you can move it this way.
Dragging the mouse in vertical direction while pressing the right mouse button (or the ctrl key and the left mouse button) scales the model. This is like zooming a camera.
Dragging the mouse in horizontal direction while pressing the right mouse button (or the ctrl key and the left mouse button) moves the point of view towards or away from the model.
The parts of the model are lying on different layers. The layer list allows you to switch them on/off.