Objects are composed of objects

Display Figure 13.

Many Alice objects are composed of smaller objects such as upper body, arm, leg, foot, hand, etc.

Every object (including the objects that are used to construct other objects) has its own center point and its own coordinate system.

By selecting the object, the coordinate system can be exposed showing three orthogonal axes colored red, green, and blue as shown in Figure 13.  (The green axis is hidden in Figure 13.)

Figure 13. Red and blue axes of lower left leg showing.