Motivation

• Sounds can be triggered by viewer actions
  • Clicks, horn honks, door latch noises
• Sounds can be continuous in the background
  • Wind, crowd noises, elevator music
• Sounds emit from a location, in a direction, within an area

Creating sounds

Sounds have two components:

• A sound source providing a sound signal
  • Like a stereo component
• A sound emitter converts a signal to virtual sound
  • Like a stereo speaker

Syntax: AudioClip

An AudioClip node creates a digital sound source:

• url - a sound file URL
• pitch - playback speed
• playback controls, like a TimeSensor node

Syntax: MovieTexture

A MovieTexture node creates a movie sound source:

• url - a texture movie file URL
• speed - playback speed
• playback controls, like a TimeSensor node

Selecting sound source types

Supported by the AudioClip node:

• MP3 or WAV - digital sound files
  Good for sound effects

Supported by the MovieTexture node:

• MP4 - movie file with sound
  Good for virtual TVs

Syntax: Sound

A Sound node describes a sound emitter:

• source - AudioClip or MovieTexture node
• location and direction - emitter placement

A Sound node describes a sound emitter:

• intensity - volume
• spatialize - use spatialize processing
• priority - prioritize the sound

A Sound node describes a sound emitter:

• minFront, minBack - inner ellipsoid
• maxFront, maxBack - outer ellipsoid

Setting the sound range

• The sound range fields specify two ellipsoids
  • minFront and minBack control an inner ellipsoid
  • maxFront and maxBack control an outer ellipsoid
• Sound has a constant volume inside the inner ellipsoid
• Sound drops to zero volume from the inner to the outer ellipsoid

Creating triggered sounds

AudioClip node:

• loop FALSE
• Set startTime from a sensor node

Sound node:

• spatialize TRUE
• minFront etc. with small values
• priority 1.0

A sample using triggered sound

Creating continuous localized sounds

AudioClip node:

• loop TRUE
• startTime 0.0 (default)
• stopTime 0.0 (default)

Sound node:

• spatialize TRUE (default)
• minFront etc. with medium values
• priority 0.0 (default)

A sample using continuous localized sound

Creating continuous background sounds

AudioClip node:

• loop TRUE
• startTime 0.0 (default)
• stopTime 0.0 (default)

Sound node:

• spatialize FALSE (default)
• minFront etc. with large values
• priority 0.0 (default)

Summary

An AudioClip node or a MovieTexture node describe a sound source:

• A URL gives the sound file
• Looping, start time, and stop time control playback

A Sound node describes a sound emitter:

• A source node provides the sound
• Range fields describe the sound volume