2.1.2. 3D-View Help

The section describes how you can control the three-dimensional view. The three-dimensional view can be manipulated with the mouse and some modifier keys. The following sections describe the effect of the different mouse buttons and modifier keys on manipulating the view.

2.1.2.1. Left Mouse Button

If you can imagine an invisible sphere around the scene (i.e. everything visible in the view) and then when you use the left mouse button and click on a point, the point at which you click is the place where you’re setting the starting point for the rotation of the sphere. Now when you drag the mouse, the scene is transformed as if you are pulling the sphere around by a piece of string attached to the clicked point.

We can perform a pure roll or yaw transform of the scene, if we can click outside this invisible sphere (sometimes this is not possible if all of the visible scene is not within the confines of the view) and move the mouse in purely vertical or horizontal manner. In practice, this is quite difficult to do.

Note

By default, there are no modify buttons used in this mode, however, modifier key functionality is often added to suit a particular application.

2.1.2.2. Middle Mouse Button

The middle mouse button can be used to pan the scene. Panning the scene results in a translation from the current viewpoint.

Note

By default, there are no modified buttons used in this mode.

2.1.2.3. Right Mouse Button

The right mouse button is used for zooming. The zoom applied is what is known as a fly-by-zoom where it appears as if the viewer is walking towards or away from the scene. Clicking and dragging down the screen will make it appear as if you are walking away from the scene and clicking and dragging up the screen will make it appear as if you are walking towards the scene.

Note

Using the shift key modifier we can change the type zoom. The shift key changes the zoom to a telephoto lens type of zoom in this mode it is as if the viewer is standing still and using the zoom on a camera or pair of binoculars to change the view.