SceneGraph

Index

User

Derived from:	TransformNode3D
Class name:	User3D
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 the SceneGraph API, 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 representation 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.

Function List

Name	XE_user_set_position
Arguments	int node_id, float x, float y, float z
Return Type	bool
Description	Sets the user's position Parameters: - node_id, the node's id - x, the x value of the position vector in world coordinates (Default value is 0.0) - y, the y value of the position vector in world coordinates (Default value is 0.0) - z, the z value of the position vector in world coordinates (Default value is 10.0) Returns true if the node id was found
Notes:

Name	XE_user_get_position
Arguments	int node_id, float& x, float& y, float& z
Return Type	bool
Description	Retrieves the user's position Parameters: - node_id, the node's id - x, the x value of the position vector in world coordinates - y, the y value of the position vector in world coordinates - z, the z value of the position vector in world coordinates Returns true if the node id was found
Notes:

Name	XE_user_set_target
Arguments	int node_id, float x, float y, float z
Return Type	bool
Description	Sets the user's target point Parameters: - node_id, the node's id - x, the x value of the target vector in world coordinates (Default value is 0.0) - y, the y value of the target vector in world coordinates (Default value is 0.0) - z, the z value of the target vector in world coordinates (Default value is -1.0) Returns true if the node id was found
Notes:

Name	XE_user_get_target
Arguments	int node_id, float& x, float& y, float& z
Return Type	bool
Description	Retrieves the user's target point Parameters: - node_id, the node's id - x, the x value of the target vector in world coordinates - y, the y value of the target vector in world coordinates - z, the z value of the target vector in world coordinates Returns true if the node id was found
Notes:

Name	XE_user_set_linear_speed
Arguments	int node_id, float lsp
Return Type	bool
Description	Sets the speed at which the user rotation is updated Parameters: - node_id, the node's id - asp, the angular speed (Default value is 1.0) Returns true if the node id was found
Notes:

Name	XE_user_get_linear_speed
Arguments	int node_id, float asp
Return Type	bool
Description	Retrieves the user's angular speed Parameters: - node_id, the node's id - asp, the angular speed Returns true if the node id was found
Notes:

Name	XE_user_set_angular_speed
Arguments	int node_id, float x, float y, float z
Return Type	bool
Description	Sets the user target Parameters: - node_id, the node's id - x, the x value of the target vector in world coordinates (Default value is 0.0) - y, the y value of the target vector in world coordinates (Default value is 0.0) - z, the z value of the target vector in world coordinates (Default value is -1.0) Returns true if the node id was found
Notes:

Name	XE_user_get_angular_speed
Arguments	int node_id, float& asp
Return Type	bool
Description	Retrieves the user target Parameters: - node_id, the node's id - x, the x value of the target vector in world coordinates - y, the y value of the target vector in world coordinates - z, the z value of the target vector in world coordinates Returns true if the node id was found
Notes:

Name	XE_user_attach_to_input_node
Arguments	int user_node_id, int input_node_id
Return Type	bool
Description	Attaches the user node to an input node, so that the user is updated based on input (keyboard, mouse, joystick, etc.) Parameters: - user_node_id, the user's node's id - input_node_id, the input's node's in Returns true if both nodes' ids were found
Notes:

Name	XE_user_attached_to_input_node
Arguments	int user_node_id, int& input_node_id
Return Type	bool
Description	Retrieves the input node id this user is attached to Parameters: - user_node_id, the user's node's id - input_node_id, the input's node's in Returns true if both nodes' ids were found, otherwise input_node_id is set to -1
Notes:

Scene Description Language Declaration

XML node name

user

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 SceneGraph, 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 representation 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 (0,0,10).
lookat	VEC3	Where the user initially points to. Default value is (0,0,-1).
target	VEC3	Same as lookat.
linear_speed	FLOAT	The linear speed of the user in world units. Default value is 3.0.
angular_speed	FLOAT	The angular speed of the user in world units. Default value is 1.0.

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
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 (0,0,10).
lookat	VEC3	Where the user initially points to. Default value is (0,0,-1).
target	VEC3	Same as lookat.
linear_speed	FLOAT	The linear speed of the user in world units. Default value is 3.0.
angular_speed	FLOAT	The angular speed of the user in world units. Default value is 1.0.

Inherited messages:

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

Redefined messages:

Obsolete messages:

translation, scale, rotation

Example

<world ambient="0.3 0.3 0.3" background="0.2 0.2 0.2">
   
    <camera name="first_person" aperture="50.0"
            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" linear_speed="2.0" angular_speed="0.5
          position="0,50,50" target="0,0,-10" input="MouseKeyboard">
    </user>

    <input name="MouseKeyboard" devicename="device0">
    </input>
    
</world>

Last updated: 3 Jun. 2013