Types of 3D User Interaction

There are two basic forms of interaction that we will consider in this chapter. The first is 2D based and is familiar to anyone who uses a computer. Examples of 2D interaction include the use of icons, buttons, and other widgets that exist on the user's desktop. In Java 3D, changes to the scene graph are made using the standard Swing and AWT components.

The second form of user interaction is 3D based and involves events detected within the coexistence space of the user and the 3D scene. In other words, user interaction in 3D requires that the user's actions in the real world be interpreted in coordinates in the virtual world and vice versa. This can be a challenging problem and is solved by finding a common space for a whole series of transforms. In order to address these challenges, Java 3D provides two important abstractions. We begin by describing the central class for interaction in Java 3D, the Behavior class.