H3D::Sound Class Reference
[X3D node classes.]

The Sound node specifies the spatial presentation of a sound in a X3D scene. More...

#include <H3D/Sound.h>

Inheritance diagram for H3D::Sound:

Inheritance graph

List of all members.

Classes

class  ALSoundSetup
 Field that calls ALrender() when a field routed to it has generated an event. More...
class  SFSoundSourceNode
 The SFSoundSourceNode registers the Sound node in the X3DSoundSourceNode that is put into the field. More...

Public Member Functions

 Sound (Inst< SFNode > _metadata=0, Inst< SFVec3f > _direction=0, Inst< SFFloat > _intensity=0, Inst< SFVec3f > _location=0, Inst< SFFloat > _maxBack=0, Inst< SFFloat > _maxFront=0, Inst< SFFloat > _minBack=0, Inst< SFFloat > _minFront=0, Inst< SFFloat > _priority=0, Inst< SFSoundSourceNode > _source=0, Inst< SFBool > _spatialize=0, Inst< ALSoundSetup > _soundSetup=0)
 Constructor.
virtual void traverseSG (TraverseInfo &ti)
 Traverse the scenegraph.
virtual void ALrender ()
 Perform the OpenAL calls to render the sound node.

Public Attributes

auto_ptr< SFVec3fdirection
 The direction field specifies the direction of the ellipsoids.
auto_ptr< SFFloatintensity
 The intensity field adjusts the loudness (decibels) of the sound emitted by the Sound node.
auto_ptr< SFVec3flocation
 The location field determines the location of the sound emitter in the local coordinate system.
auto_ptr< SFFloatmaxBack
 The maxBack field specifies the back value of the outer ellipsoid.
auto_ptr< SFFloatmaxFront
 The maxFront field specifies the front value of the outer ellipsoid.
auto_ptr< SFFloatminBack
 The minBack field specifies the back value of the outer ellipsoid.
auto_ptr< SFFloatminFront
 The minFront field specifies the front value of the outer ellipsoid.
auto_ptr< SFFloatpriority
 The priority field provides a hint for the browser to choose which sounds to play when there are more active Sound nodes than can be played at once due to either limited system resources or system load.
auto_ptr< SFSoundSourceNodesource
 The source field specifies the sound source for the Sound node.
auto_ptr< SFBoolspatialize
 The spatialize field specifies if the sound is perceived as being directionally located relative to the viewer.
auto_ptr< ALSoundSetupsoundSetup
 Field that calls ALrender() when a field routed to it has generated an event.
auto_ptr< SFMatrix4faccForwardMatrix
 The matrix from local space to global space.

Static Public Attributes

static H3DNodeDatabase database
 The H3DNodeDatabase for this node.


Detailed Description

The Sound node specifies the spatial presentation of a sound in a X3D scene.

The sound is located at a point in the local coordinate system and emits sound in an elliptical pattern (defined by two ellipsoids). The ellipsoids are oriented in a direction specified by the direction field. The shape of the ellipsoids may be modified to provide more or less directional focus from the location of the sound.

The source field specifies the sound source for the Sound node. If the source field is not specified, the Sound node will not emit audio. The source field shall specify an AudioClip node .

The intensity field adjusts the loudness (decibels) of the sound emitted by the Sound node. The intensity field has a value that ranges from 0.0 to 1.0 and specifies a factor which shall be used to scale the normalized sample data of the sound source during playback. A Sound node with an intensity of 1.0 shall emit audio at its maximum loudness (before attenuation), and a Sound node with an intensity of 0.0 shall emit no audio. Between these values, the loudness should increase linearly from a -20 dB change approaching an intensity of 0.0 to a 0 dB change at an intensity of 1.0.

The priority field provides a hint for the browser to choose which sounds to play when there are more active Sound nodes than can be played at once due to either limited system resources or system load. The priority field ranges from 0.0 to 1.0, with 1.0 being the highest priority and 0.0 the lowest priority.

The location field determines the location of the sound emitter in the local coordinate system. A Sound node's output is audible only if it is part of the traversed scene. Sound nodes that are descended from LOD, Switch, or any grouping or prototype node that disables traversal of its children are not audible unless they are traversed. If a Sound node is disabled by a Switch or LOD node, and later it becomes part of the traversal again, the sound shall resume where it would have been had it been playing continuously.

The Sound node has an inner ellipsoid that defines a volume of space in which the maximum level of the sound is audible. Within this ellipsoid, the normalized sample data is scaled by the intensity field and there is no attenuation. The inner ellipsoid is defined by extending the direction vector through the location. The minBack and minFront fields specify distances behind and in front of the location along the direction vector respectively. The inner ellipsoid has one of its foci at location (the second focus is implicit) and intersects the direction vector at minBack and minFront.

The Sound node has an outer ellipsoid that defines a volume of space that bounds the audibility of the sound. No sound can be heard outside of this outer ellipsoid. The outer ellipsoid is defined by extending the direction vector through the location. The maxBack and maxFront fields specify distances behind and in front of the location along the direction vector respectively. The outer ellipsoid has one of its foci at location (the second focus is implicit) and intersects the direction vector at maxBack and maxFront.

The minFront, maxFront, minBack, and maxBack fields are defined in local coordinates, and shall be greater than or equal to zero. The minBack field shall be less than or equal to maxBack, and minFront shall be less than or equal to maxFront. The ellipsoid parameters are specified in the local coordinate system but the ellipsoids' geometry is affected by ancestors' transformations.

Between the two ellipsoids, there shall be a linear attenuation ramp in loudness, from 0 dB at the minimum ellipsoid to -20 dB at the maximum ellipsoid:

attenuation = -20 (d' / d")

where d' is the distance along the location-to-viewer vector, measured from the transformed minimum ellipsoid boundary to the viewer, and d" is the distance along the location-to-viewer vector from the transformed minimum ellipsoid boundary to the transformed maximum ellipsoid boundary.

The spatialize field specifies if the sound is perceived as being directionally located relative to the viewer. If the spatialize field is TRUE and the viewer is located between the transformed inner and outer ellipsoids, the viewer's direction and the relative location of the Sound node should be taken into account during playback. If the spatialize field is FALSE, directional effects are ignored, but the ellipsoid dimensions and intensity will still affect the loudness of the sound. If the sound source is multi-channel, the source shall retain its channel separation during playback.

Internal routes:
Sound.dot

Member Function Documentation

void Sound::traverseSG ( TraverseInfo ti  )  [virtual]

Traverse the scenegraph.

Saves the accForwardMatrix and calls traverseSG() for source.

Parameters:
ti The TraverseInfo object containing information about the traversal.

Reimplemented from H3D::Node.

References accForwardMatrix, H3D::TraverseInfo::getAccForwardMatrix(), source, and H3D::Node::traverseSG().


Member Data Documentation

The direction field specifies the direction of the ellipsoids.

Access type: inputOutput
Default value: Vec3f( 0, 0, 1 )

Sound_direction.dot

Referenced by ALrender(), and Sound().

The intensity field adjusts the loudness (decibels) of the sound emitted by the Sound node.

The intensity field has a value that ranges from 0.0 to 1.0 and specifies a factor which shall be used to scale the normalized sample data of the sound source during playback. A Sound node with an intensity of 1.0 shall emit audio at its maximum loudness (before attenuation), and a Sound node with an intensity of 0.0 shall emit no audio. Between these values, the loudness should increase linearly from a -20 dB change approaching an intensity of 0.0 to a 0 dB change at an intensity of 1.0.

Access type: inputOutput
Default value: 1

Sound_intensity.dot

Referenced by ALrender(), and Sound().

The location field determines the location of the sound emitter in the local coordinate system.

Access type: inputOutput
Default value: Vec3f( 0, 0, 0 )

Sound_location.dot

Referenced by ALrender(), and Sound().

The maxBack field specifies the back value of the outer ellipsoid.

Access type: inputOutput
Default value: 10

Sound_maxBack.dot

Referenced by ALrender(), and Sound().

The maxFront field specifies the front value of the outer ellipsoid.

Access type: inputOutput
Default value: 10

Sound_maxFront.dot

Referenced by ALrender(), and Sound().

The minBack field specifies the back value of the outer ellipsoid.

Access type: inputOutput
Default value: 1

Sound_minBack.dot

Referenced by ALrender(), and Sound().

The minFront field specifies the front value of the outer ellipsoid.

Access type: inputOutput
Default value: 1

Sound_minFront.dot

Referenced by ALrender(), and Sound().

The priority field provides a hint for the browser to choose which sounds to play when there are more active Sound nodes than can be played at once due to either limited system resources or system load.

The priority field ranges from 0.0 to 1.0, with 1.0 being the highest priority and 0.0 the lowest priority.

Access type: inputOutput
Default value: 0

Sound_priority.dot

Referenced by Sound().

Field that calls ALrender() when a field routed to it has generated an event.

Referenced by Sound().

The source field specifies the sound source for the Sound node.

If the source field is not specified, the Sound node will not emit audio.

Access type: inputOutput
Default value: 0

Sound_source.dot

Referenced by traverseSG().

The spatialize field specifies if the sound is perceived as being directionally located relative to the viewer.

If the spatialize field is TRUE and the viewer is located between the transformed inner and outer ellipsoids, the viewer's direction and the relative location of the Sound node should be taken into account during playback. If the spatialize field is FALSE, directional effects are ignored, but the ellipsoid dimensions and intensity will still affect the loudness of the sound.

Access type: inputOutput
Default value: TRUE

Sound_spatialize.dot

Referenced by ALrender(), and Sound().


The documentation for this class was generated from the following files:

Generated on Fri Nov 7 10:30:57 2008 for H3D API by  doxygen 1.5.7