User Guide

ADOBE ATMOSPHERE 277
User Guide
Copyright ©2002 Adobe Systems Incorporated. All rights reserved.
Scene Objects
Actor
The Actor module is used to represent the user of the application as they navigate the 3-D world. It has a position and
orientation that is changed as the user moves. It corresponds the position of the user’s avatar as seen by other people
(and by the user in third person view). The actor also includes properties that control the motion of the user. These
include world-relative and screen-relative velocities, fl ags for enabling and disabling gravity and collisions, fl ags to
disable the default navigation scheme and functions for setting and retrieving the orientation of the user.
The user orientation is unusual in that it consists of two parts, a body orientation, which is contrained to only
rotate about the Y axis, and the head orientation that includes rotation angles at the neck. The default user interface
controls both. The body orientation is used to control rotations about Y, and to rotate the displayed avatar, while the
head orientation determines the orientation of the camera in fi rst person view. See the Camera module for more
information.
If you desire to move the Actor for any purpose, it is best to use the function “setPositionAvoidingCollisions(Ve
ctor)”. This function will account for other objects present at the desired location, and cause the physics engine
to momentarily turn off collisions while the function attempts to move the Actor to the desired position. These
precautions prevent erratic behavior due to unforseen collisions which may be present. Note that if the Avatar is
bigger than the available space at the destination, the avatar may fall through the fl oor (and continue falling if gravity
is ‘on’). Be sure to leave suffi cient height for large Avatars under these conditions.
Global Properties
theActor
The global object representing the person navigating.
dump(theActor); // Display the user’s properties
Properties
type
The object’s type. Returns “theActor”.
if (foo.type == ‘theActor’) { ... }
avatarURL
The URL of the Actor’s current actual avatar. Note that if the user selects a new avatar, theActor.avatarURL
will not update until the new avatar is actually loaded and in use. Similarly, when a user fi rst enters a world or
launches the Browser, theActor.avatarURL will remain undefi ned until their avatar has loaded. This value is read-
only.