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# dripwater

dripwater -- Semi-physical model of a water drop.

## Description

dripwater is a semi-physical model of a water drop. It is one of the PhISEM percussion opcodes. PhISEM (Physically Informed Stochastic Event Modeling) is an algorithmic approach for simulating collisions of multiple independent sound producing objects.

## Syntax

ar dripwater kamp, idettack [, inum] [, idamp] [, imaxshake] [, ifreq] [, ifreq1] [, ifreq2]

## Initialization

idettack -- period of time over which all sound is stopped

inum (optional) -- The number of beads, teeth, bells, timbrels, etc. If zero, the default value is 10.

idamp (optional) -- the damping factor, as part of this equation:

damping_amount = 0.996 + (idamp * 0.002)

The default damping_amount is 0.996 which means that the default value of idamp is 0. The maximum damping_amount is 1.0 (no damping). This means the maximum value for idamp is 2.0.

The recommended range for idamp is usually below 75% of the maximum value. Rasmus Ekman suggests a range of 1.4-1.75. He also suggests a maximum value of 1.9 instead of the theoretical limit of 2.0.

imaxshake (optional, default=0) -- amount of energy to add back into the system. The value should be in range 0 to 1.

ifreq (optional) -- the main resonant frequency. The default value is 450.

ifreq1 (optional) -- the first resonant frequency. The default value is 600.

ifreq2 (optional) -- the second resonant frequency. The default value is 750.

## Performance

kamp -- Amplitude of output. Note: As these instruments are stochastic, this is only an approximation.

## Examples

Here is an example of the dripwater opcode. It uses the files dripwater.orc and dripwater.sco.

Example 1. Example of the dripwater opcode.

    /* dripwater.orc */
    sr = 44100
    kr = 4410
    ksmps = 10
    nchnls = 1

    instr 01  ;example of a water drip
    a1  line 5, p3, 5  ;preset an amplitude boost
    a2  dripwater p4, 0.01, 0, .9  ;dripwater needs a little amplitude help at these values
    a3  product a1, a2 ;increase amplitude
        out a3
        endin
    /* dripwater.orc */

    /* dripwater.sco */
    i1 0 1 20000
    e
    /* dripwater.sco */

## See Also

bamboo, guiro, sleighbells, tambourine

## Credits

Author: Perry Cook, part of the PhISEM (Physically Informed Stochastic Event Modeling)
Adapted by John ffitch
University of Bath, Codemist Ltd.
Bath, UK

New in Csound version 4.07

Added notes by Rasmus Ekman on May 2002.

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