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Viewing 3D Worlds
Most 3D graphics systems provide many ways to view 3D worlds. There exist controls for viewing a specific object from many different points of view, as well as controls for viewing a scene from different directions. Some of these views are contolled by mouse and others by type-in or both.
- Mouse controls for viewing an object. If you click on an object
a set of small green balls and white cubes which surround the
object appear.
These act as control points which let you manipulate views in the following ways:- If you click on a green ball a circle and some arrows appear:
these allow you to rotate an object about a specific axis.
- If you click on a small white cube you can expand or shrink
the object. Pressing a SHIFT or CONTOL key lets you
constrain the change along a specific dimension.
- Clicking on the surface itself exposes a 4-way set of arrows
which let you move the object. Clicking on the face toward you
lets you move it in the X-Y plane; clicking near the top
lets you move it in the X-Z or Y-Z plane. Again SHIFT/CONTROL
keys constrain the movements.
- If you click on a green ball a circle and some arrows appear:
these allow you to rotate an object about a specific axis.
- Mouse controls for viewing a scene. An icon that looks like crossed arrows lets you pan thru a scene; another icon, the Universal Manipulator, lets you move in all directions including the Z-plane. An icon that looks like a hand lets you view the scene from any angle and from any dimension.
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