The SceneGraph3D Description Language

Index

proximitytrigger

Derived from:

Node3D

Class name:

ProximityTrigger3D

Placement:

Anywhere

Description:

This is the first of a family of triggers that are available in the scene graph. It triggers three types of events, depending on the containment of one or more of registered nodes in its area of effect. The nodes are registered through messages to the proximitytrigger object. The three events correspond to a node entering, exiting and being inside the trigger's area of effect. The area of effect of the trigger can be a spherical one, a box, or a halfspace (the scene file contains the equation of the dividing plane in space). The position, orientation and scale of the trigger's extends are affected by the transformations applied to the node.

Special notes:

Inherited attributes:

name, active, visible

New attributes:

attribute	type	description
shape	OPTION sphere box plane	Defines the shape of the area of effect of the proximity sensor. The default shape is the sphere.
position	VEC3	The center of the trigger. Applicable to the sphere and box shape types. Initially set to (0,0,0).
radius	FLOAT	The radius of the sphere. Applicable only to the spherical shape. Initial value is 1.0.
normal	VEC3	The normal of the dividing plane. Applicable only to the planar trigger shape. Initial value is (0,1,0).
offset	FLOAT	The offset of the plane from the local coordinate system origin. Initial value is 0.0.
size	VEC3	The size of the box in local units. Applicable only to the box-shaped trigger. Default value is (1,1,1).
mode	OPTION center volume	Defines the criterion for containment of a node to the trigger's area of effect. If center is selected, the trigger checks if the position (center) of the queries node lies within the area of effect. If the volume option is used, the entire volume of the queried node must lie within the area of effect in order to trigger an enter event. Currently, only the center mode is supported.

Events:

event name	condition
enter	Issued whenever the first of the registered nodes is found entering the area of the effect of the trigger.
exit	Issued when the last of the registered nodes exits the area of effect of the trigger.
inside	Issued when at least one of the registered nodes lies within the area of effect of the trigger.

Inherited events:

New messages:

attribute	value	description
position	VEC3	Same as corresponding node attribute.
size	VEC3	Same as corresponding node attribute.
offset	FLOAT	Same as corresponding node attribute.
normal	VEC3	Same as corresponding node attribute.
radius	FLOAT	Same as corresponding node attribute.
watch	STRING	Declare a node to check for containment. Multiple nodes can be queried this way. See the event section for the exact conditions of event triggering.

Inherited messages:

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

Redefined messages:

Obsolete messages:

Example

<world ambient_occlusion="ssao" bloom="yes" shadows="disk" 
       ao_radius="6" ambient="0.3 0.3 0.3" defocus="yes">
       
    <eventmessage event="init" recipient="trigger1" delay="0.0" message="watch Myself">
    </eventmessage>  

    <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"
          position="0,10,100" lookat="0,10,0" input="Console">
    </user>

    <input name="Console" type="mousekeyboard">
    </input>
    
    <proximitytrigger name="trigger1" shape="sphere" radius="30" position="0,10,-50">
        <eventmessage event="enter" recipient="geom1" delay="0.0" message="hide">
        </eventmessage>
        <eventmessage event="exit" recipient="geom1" delay="0.0" message="show">
        </eventmessage>
    </proximitytrigger>

</world>

Last update: 16 Feb. 2009