TYPE: CHOP
TITLE: SpatialAudio CHOP

The SpatialAudio CHOP is the rendering engine for producing 3D audio. It uses
the Sound and Microphone objects to define positional sources and microphones,
Geometry objects to define obstructions and Acoustic CHOPs to define sound
materials and audio filters.

The first input is an optional lookup table for the volume dropoff over
distance.  This is required if the Distance Volume Loss parameter is set to
'Distance/Volume Lookup Table'. The second input is an optional 'Environment
Filter' which describes how the environment affects the frequencies of sound
traveling through it (used with the Distance Volume Loss parameter).

Parameters:
Environment
    Microphones        - Specifies the microphone objects to use.
                         One channel is created per microphone.
    Sound Sources      - Specifies the sound objects to use.
    Meters Per Unit    - Length of 1 world unit, in meters.       /meterperunit
    Speed of Sound     - The speed of sound of the environment, in    /soundvel
                         meters per second (default speed is for air). 
Effects
    Enable Distance Delay  - Enables delays over long distances, as well
                             as the doppler effect (realistic if on).
    Distance Volume Loss   - Method for calculating volume loss over distance.
        None                         - Distance does not diminish sound.
        Realistic Distance Dropoff   - Natural volume dropoff (1/d^2)
        Distance/Volume Lookup Table - Determine from the lookup table
                                       connected to the first input.
    10m Volume Loss        - How much volume is decreased after       /volloss
                             traveling 10 meters (.4=40% decrease).
    Volume Lookup Range    - The range of the distance lookup table;  /vollookup1-2
                             (10,100) means that the table describes
                             how the volume behaves from 10-100 meters.
    Use Microphone Filters - Enables or disables all microphone filters. 
    Check For Obstacles    - Turns on the algorithm for obstacle occlusion. 
    Obstacles              - Add geometry objects as an obstacles. The
                             sound material for these object must be
                             defined. The geometry detail should be low.
    Collision Detection    - Specifies the collision detection algorithm.
        Object Bounding Box    - Uses the bounding box of the entire object
                                 as the collision object (very fast).
        Primitive Bounding Box - Uses a bounding box per primitive. Good for
                                 objects that consist of separate geometries.
        Object Geometry        - Uses the actual geometry as the collision
                                 object (slowest & most accurate).
    Obstacle Softness      - If an object is between a microphone and     /obstsoft
                             a sound source, this parameter determines how
                             abruptly the cutoff is (0 = abrupt, 1 = smooth).
Echo
    Echo Method            - Computes static or dynamic environmental echoes.  
    Number of Echoes       - The number of echoes to compute.           /numecho
    Echo Delay             - The time between echoes.                   /echodelay
    Echo Volume		   - Adjusts the volume of all echoes.		/echovol
    Dynamic Echo Effect    - Percentage longer that echoes take to      /dyneffect
                             arrive than the initial sound (.5 = 50% longer)
Channel
    Compute Full Animation Range - Compute using the full animation range,    /start
                             otherwise use the start/end parameters.    /end
    Preroll                - The amount computed before the start of    /preroll
                             the interval.
    Object Sample Rate     - The rate that object are sampled at.       /objsample
    Audio Sample Rate      - The sample rate of the audio produced.    /audiosample

See also: Acoustic, Sound, Microphone
