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Sound Class Reference
[Standard Node Types]

#include <sound.h>

Inherits Node.

Inheritance diagram for Sound:

Inheritance graph
[legend]
List of all members.

Public Member Functions

 Sound (const char *name="")
virtual ~Sound ()
virtual unsigned int nbFields () const
virtual FieldHandle field (const std::string &n)
virtual FieldHandle field (const unsigned int i)
virtual bool isSetToDefaultValue (const unsigned int i) const
virtual unsigned int nbEventsIn () const
virtual EventInHandle eventIn (const std::string &n)
virtual EventInHandle eventIn (const unsigned int i)
virtual unsigned int nbEventsOut () const
virtual EventOutHandle eventOut (const std::string &n)
virtual EventOutHandle eventOut (const unsigned int i)
const char * typeName () const
virtual Node * duplicate () const
virtual Node * duplicate (std::map< const Node *, Node * > &) const

Public Attributes

Exposed Fields
A field that is capable of receiving events via an eventIn to change its value(s), and generating events via an eventOut when its value(s) change.

SFVec3f direction
SFFloat intensity
SFVec3f location
SFFloat maxBack
SFFloat maxFront
SFFloat minBack
SFFloat minFront
SFFloat priority
SFNode source
Fields
A property or attribute of a node. Each node type has a fixed set of fields. Fields may contain various kinds of data and one or many values. Each field has a default value.

SFBool spatialize
Events In
EventIn< SFVec3f > set_direction
EventIn< SFFloat > set_intensity
EventIn< SFVec3f > set_location
EventIn< SFFloat > set_maxBack
EventIn< SFFloat > set_maxFront
EventIn< SFFloat > set_minBack
EventIn< SFFloat > set_minFront
EventIn< SFFloat > set_priority
EventIn< SFNode > set_source
Events Out
EventOut< SFVec3f > direction_changed
EventOut< SFFloat > intensity_changed
EventOut< SFVec3f > location_changed
EventOut< SFFloat > maxBack_changed
EventOut< SFFloat > maxFront_changed
EventOut< SFFloat > minBack_changed
EventOut< SFFloat > minFront_changed
EventOut< SFFloat > priority_changed
EventOut< SFNode > source_changed

Detailed Description

Here is the documentation for this node type, from the ISO standard.

+6.61 Sound

The Sound node specifies the spatial presentation of a sound in a VRML 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 either an AudioClip node or a MovieTexture node. If a MovieTexture node is specified as the sound source, the MovieTexture shall refer to a movie format that supports sound (e.g., MPEG1-Systems, see 2.[MPEG]).

The intensity field adjusts the loudness (decibels) of the sound emitted by the Sound node (note: this is different from the traditional definition of intensity with respect to sound; see E.[SNDA]). 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. 7.3.4, Sound priority, attenuation, and spatialization, describes a recommended algorithm for determining which sounds to play under such circumstances. 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 (i.e., drawing) 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 (see Figure 6.14).

Sound Node Geometry

Figure 6.14 -- Sound node geometry

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. Details outlining the minimum required spatialization functionality can be found in 7.3.4, Sound priority, attenuation, and spatialization. If the spatialize field is FALSE, then 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 (e.g., stereo), then the source should retain its channel separation during playback.

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Constructor & Destructor Documentation

Sound (  const char *  name = ""  ) 
 

Construct a node with all its fields set to default value, which is equivalent to the code below: 

  direction.setXYZ(0,0,1);
  intensity = 1;
  location.setXYZ(0,0,0);
  maxBack = 10;
  maxFront = 10;
  minBack = 1;
  minFront = 1;
  priority = 0;
  spatialize = true;

~Sound (   )  [virtual]
 

Virtual destructor, does nothing

Member Function Documentation

wrl::Node * duplicate (  std::map< const Node *, Node * > &   )  const [virtual]
 

Implements Node.

wrl::Node * duplicate (   )  const [virtual]
 

Returns a deep copy of this node, that is a fully independant node with all children (if any) also copied. This is mainly useful for instanciating protos.

Implements Node.

wrl::Node::EventInHandle eventIn (  const unsigned int  n  )  [virtual]
 

Return a handle on the i th event in of the node or a "unknown" typed handle if there is no such node. emarks This class has no eventIn. This function is useful, with nbEventsIn() if you want to traverse all events in of a Node.

Implements Node.

wrl::Node::EventInHandle eventIn (  const std::string &  n  )  [virtual]
 

Return a handle on the event in named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

  • set_direction
  • set_intensity
  • set_location
  • set_maxBack
  • set_maxFront
  • set_minBack
  • set_minFront
  • set_priority
  • set_source

Implements Node.

wrl::Node::EventOutHandle eventOut (  const unsigned int  n  )  [virtual]
 

Return a handle on the i th event out of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

  • 0 : direction_changed
  • 1 : intensity_changed
  • 2 : location_changed
  • 3 : maxBack_changed
  • 4 : maxFront_changed
  • 5 : minBack_changed
  • 6 : minFront_changed
  • 7 : priority_changed
  • 8 : source_changed This function is useful, with nbEventsOut() if you want to traverse all events in of a Node.

Implements Node.

wrl::Node::EventOutHandle eventOut (  const std::string &  n  )  [virtual]
 

Return a handle on the event out named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

  • direction_changed
  • intensity_changed
  • location_changed
  • maxBack_changed
  • maxFront_changed
  • minBack_changed
  • minFront_changed
  • priority_changed
  • source_changed

Implements Node.

wrl::Node::FieldHandle field (  const unsigned int  n  )  [virtual]
 

Return a handle on the i th field of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

  • 0 : direction
  • 1 : intensity
  • 2 : location
  • 3 : maxBack
  • 4 : maxFront
  • 5 : minBack
  • 6 : minFront
  • 7 : priority
  • 8 : source
  • 9 : spatialize This function is useful, with nbFields() if you want to traverse all fields of a Node.

Implements Node.

wrl::Node::FieldHandle field (  const std::string &  n  )  [virtual]
 

Return a handle on the field named n of the node or a "unknown" typed handle if there is no such field. Valid names are:

  • direction
  • intensity
  • location
  • maxBack
  • maxFront
  • minBack
  • minFront
  • priority
  • source
  • spatialize

Implements Node.

bool isSetToDefaultValue (  const unsigned int  i  )  const [virtual]
 

Implements Node.

unsigned int nbEventsIn (   )  const [inline, virtual]
 

Returns the number of events in for this node type.

Implements Node.

unsigned int nbEventsOut (   )  const [inline, virtual]
 

Returns the number of events out for this node type.

Implements Node.

unsigned int nbFields (   )  const [inline, virtual]
 

Returns the number of fields (exposed or not) for this node type.

Implements Node.

const char * typeName (   )  const [inline, virtual]
 

Returns "Sound". Useful for printing.

Implements Node.

Member Data Documentation

SFVec3f direction
 

See Detailed Description for meaning of this field. Default value is set to 

       direction.setXYZ(0,0,1);

EventOut<SFVec3f> direction_changed
 

Changed event associated to exposedField direction

SFFloat intensity
 

See Detailed Description for meaning of this field. Default value is set to 

       intensity = 1;

EventOut<SFFloat> intensity_changed
 

Changed event associated to exposedField intensity

SFVec3f location
 

See Detailed Description for meaning of this field. Default value is set to 

       location.setXYZ(0,0,0);

EventOut<SFVec3f> location_changed
 

Changed event associated to exposedField location

SFFloat maxBack
 

See Detailed Description for meaning of this field. Default value is set to 

       maxBack = 10;

EventOut<SFFloat> maxBack_changed
 

Changed event associated to exposedField maxBack

SFFloat maxFront
 

See Detailed Description for meaning of this field. Default value is set to 

       maxFront = 10;

EventOut<SFFloat> maxFront_changed
 

Changed event associated to exposedField maxFront

SFFloat minBack
 

See Detailed Description for meaning of this field. Default value is set to 

       minBack = 1;

EventOut<SFFloat> minBack_changed
 

Changed event associated to exposedField minBack

SFFloat minFront
 

See Detailed Description for meaning of this field. Default value is set to 

       minFront = 1;

EventOut<SFFloat> minFront_changed
 

Changed event associated to exposedField minFront

SFFloat priority
 

See Detailed Description for meaning of this field. Default value is set to 

       priority = 0;

EventOut<SFFloat> priority_changed
 

Changed event associated to exposedField priority

EventIn<SFVec3f> set_direction
 

Set event associated to exposedField direction

EventIn<SFFloat> set_intensity
 

Set event associated to exposedField intensity

EventIn<SFVec3f> set_location
 

Set event associated to exposedField location

EventIn<SFFloat> set_maxBack
 

Set event associated to exposedField maxBack

EventIn<SFFloat> set_maxFront
 

Set event associated to exposedField maxFront

EventIn<SFFloat> set_minBack
 

Set event associated to exposedField minBack

EventIn<SFFloat> set_minFront
 

Set event associated to exposedField minFront

EventIn<SFFloat> set_priority
 

Set event associated to exposedField priority

EventIn<SFNode> set_source
 

Set event associated to exposedField source

SFNode source
 

See Detailed Description for meaning of this field. Default value is set to SFNode default value

EventOut<SFNode> source_changed
 

Changed event associated to exposedField source

SFBool spatialize
 

See Detailed Description for meaning of this field. Default value is set to 

       spatialize = true;

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