Zoom

Use it!

(3D only) Used to change the magnification of the view volume. In a view with perspective projection, the eye point position is changed relative to a point in the view volume — usually a point on an element. The way in which this view control behaves, depends on whether or not Dynamic Display is active.

Currently, this tool takes its Dynamic Display setting from the following view controls — Rotate View, Pan View, and Change View Perspective.

To zoom in or out of a 3D view

1. Select the Zoom view control.


2. Enter a data point to define an origin to zoom about. This point becomes the center point in the view volume and sets the Active Depth.
   A cube dynamically displays, representing the view volume to be displayed.


3. Enter a data point to define the extent of the volume to be displayed.
   To zoom in, this cube should be small; to zoom out, it should be big.
   With Dynamic Display off, the original cube remains displayed, and another cube displays. This second cube indicates the defined volume. Making this second cube larger or smaller than the first, zooms the view in or out respectively.
   With Dynamic Display on, the view updates to center the display of the elements in the defined volume. Moving the pointer away or toward the center of the view zooms the view in or out respectively.


4. Enter a data point to complete the zoom action.

Key-in: ZOOM 3D

Rather than changing the perspective angle as does a camera's zoom lens, this view control lets you move closer to or further away from an element. (A zoom lens is useful with a real camera because it is often inconvenient to actually move closer to or further from the subject. In a computer model this is no problem.)