The SceneGraph3D Description Language

Index

user

Derived from:

TransformNode3D

Class name:

User3D

Placement:

Anywhere

Description:

This type of node implements an autonomous entity that can navigate through the virtual world as a result of a controller that provides input and therefore drives the node. User is not a unique node; many users may populate the virtual world, each one representing a different actual user (e.g. for multiplayer games) or computer-controlled characters, animals or avatars in general. The user nodes do not implement a viewing system, as this is part of the camera node, which of course can be bound ( attached) to any scene graph node, including a user. Cameras and users are completely different entities in SceneGraph3D, allowing a large diversity of configurations, multiple angles, multiple users and any dynamic combination of them. User is derived from the transformation node type, which means that it can therefore contain other nodes. This makes the addition of a visual represntation of the avatar very easy, as you only add whatever node you want as the content of the user and it will move along with it.

Special notes:

Although derived from a transformation node type, all direct transformation messages are ignored.

Inherited attributes:

name, active, visible

New attributes:

attribute	type	description
input	STRING	Declares the input node that will provide all control for the user.
position	VEC3	The initial position of the user. Default value is (0,0,0).
lookat	VEC3	Where the user initially points to. Inital value is (0,0,-100).
freeroll	BOOLEAN	When true, the input controller also affects the roll of the user, otherwise, the user remains upright (the "right" axis lies on the xz plane). Default value is false.
turn	FLOAT	The rate at which the user turns. Default value is 1.0, which is quite fast.
speed	FLOAT	The linear speed of the user in world units. Default value is 1.0.
control	OPTION navigate orbit passive	Configures the type of motion the user performs with regard to the look-at point and the input parameters. If the navigate option is set (default), the user turns using its position as a pivot point. If the orbit mode is set, the user turns around the look-at point. When passive mode is used, the user ignores all input.

Events:

event name	condition
moveforward	Issued when the user moves forward. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
movebackward	Issued when the user moves backward. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
moveleft	Issued when the user moves (strafes) left. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
moveright	Issued when the user moves (strafes) right. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
tiltup	Issued when the user front direction tilts toward its "up" vector. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
tiltdown	Issued when the user front direction tilts away from its "up" vector. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
turnleft	Issued when the user front direction turns away from its "right" direction vector. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.
turnright	Issued when the user front direction turns toward its "right" direction vector. Ideal for changing in the appearance of the user when performing this action. This is independent of the input control type.

Inherited events:

New messages:

attribute	value	description
control	OPTION navigate orbit passive	Same as corresponding node attribute.
freeroll	BOOLEAN	Same as corresponding node attribute.
speed	FLOAT	Same as corresponding node attribute.
turn	FLOAT	Same as corresponding node attribute.
position	VEC3	Same as corresponding node attribute.
lookat	VEC3	Same as corresponding node attribute.
input	STRING	Same as corresponding node attribute.

Inherited messages:

active, visible, hide, show, deactivate, enable, activate, disable

Redefined messages:

Obsolete messages:

translation, scale, rotation

Example

<world ambient_occlusion="ssao" bloom="yes" shadows="disk" 
       ao_radius="6" ambient="0.3 0.3 0.3" defocus="yes">
   
    <camera name="first_person" apperture="50.0" 
            focal_distance ="30.0" focal_range="30.0"
            near="2.0" far="1000" follow="Myself" primary="true">
    </camera> 

    <transformation name="environment" scale="1.0,1.0,1.0" translation="0,0,-10">
        
        <object name="geom1" file="arena.obj"></object>
    
    </transformation>
 
    <user name="Myself" control="navigate" speed="2.0" turn="0.5 freeroll="false" 
          position="0,50,50" lookat="0,0,-10" input="Console">
    </user>

    <input name="Console" type="mousekeyboard">
    </input>
    
</world>

Last update: 16 Feb. 2009