RTcmix Documentation

MMODALBAR -- modal-bar physical model
in RTcmix/insts/stk

quick syntax:

MMODALBAR(outsk, dur, AMP, FREQ, hardness, pos, preset[, PAN, AMPENV])

   p0 = output start time (seconds)
   p1 = duration (seconds)
   p2 = amplitude (absolute, for 16-bit soundfiles: 0-32768)
   p3 = frequency (Hz)
   p4 = stick hardness (0.0-1.0)
   p5 = stick position (0.0-1.0)
   p6 = modal preset
      - Marimba = 0
      - Vibraphone = 1
      - Agogo = 2
      - Wood1 = 3
      - Reso = 4
      - Wood2 = 5
      - Beats = 6
      - Two Fixed = 7
      - Clump = 8
   p7 = pan (0-1 stereo; 0.5 is middle) [optional; default is 0.5]
   p8 = amplitude envelope table [optional; default is 1.0]


   p2 (amplitude), p3 (frequency) and p7 (pan) can receive dynamic updates from
   a table or real-time control source.

   p8 (amplitude envelope table), if used, should be a reference to a pfield table-handle.

   Author:  Brad Garton, based on code from the Synthesis ToolKit

MMODALBAR is the "ModalBar" physical model in Perry Cook and Gary Scavone's STK, the Synthesis ToolKit.

Usage Notes

MMODALBAR uses waveguide physical modeling techniques to reproduce the sound of a range of 'struck bar' instruments, including marimba, vibraphone, agogo-bells, wood-blocks, etc.

Here's what Perry says about "ModalBar":

This class implements a number of different struck bar instruments. It inherits from the Modal class. and this about the "Modal" class:

This class contains an excitation wavetable, an envelope, an oscillator, and N resonances (non-sweeping BiQuad filters), where N is set during instantiation. The amplitude envelope table (p8, "AMPENV") is an optional parameter. It is also redundant -- the same functionality can be achieved by using a pfield-table reference in p2 ("AMP").

See also the MBANDEDWG instrument for an extended modal-model implementation.

MMODALBAR can produce other mono or stereo output.

Sample Scores

very basic:

   rtsetparams(44100, 1)
   load("MMODALBAR")

   MMODALBAR(0, 1.0, 25000, 243.0, 0.4, 0.4, 0)
   MMODALBAR(1, 1.0, 25000, 243.0, 0.4, 0.4, 1)
   MMODALBAR(2, 1.0, 25000, 243.0, 0.4, 0.4, 2)
   MMODALBAR(3, 1.0, 25000, 243.0, 0.4, 0.4, 3)
   MMODALBAR(4, 1.0, 25000, 243.0, 0.4, 0.4, 4)
   MMODALBAR(5, 1.0, 25000, 243.0, 0.4, 0.4, 5)
   MMODALBAR(6, 1.0, 25000, 243.0, 0.4, 0.4, 6)
   MMODALBAR(7, 1.0, 25000, 243.0, 0.4, 0.4, 7)
   MMODALBAR(8, 1.0, 25000, 243.0, 0.4, 0.4, 8)

slightly more advanced:

   rtsetparams(44100, 2)
   load("MMODALBAR")

   st = 0
   for (j = 0; j < 9; j = j+1)
   {
      hard = 0.0
      for (i = 0; i < 10; i = i+1)
      {
         MMODALBAR(st, 1.0, 25000, 279.0, hard, 0.4, j)
         hard = hard + 0.1
         st = st + 0.5
      }
      MMODALBAR(st, 1.0, 25000, 243.0, hard-0.01, 0.4, j)
   }

fun stuff!

   rtsetparams(44100, 2)
   load("MMODALBAR")

   amp = 20000
   ampenv = maketable("line", 1000, 0,1, 1, 1, 1.1, 0)
   pches = { 7.05, 7.07, 7.09, 7.10, 8.00, 8.03, 8.05, 8.07, 8.08, 8.09, 8.10, 9.00, 9.05, 9.07, 10.00 }
   lpches = len(pches)

   st = 0
   for (i = 0; i < 200; i = i+1)
   {
      pos = random()
      hard = random()
      inst = trand(0, 9)
      pch = pches[trand(0, lpches)]
      MMODALBAR(st, 1.0, amp*ampenv, cpspch(pch), hard, pos, inst)
      st = st + 0.11
   }

See Also

AMINST, FMINST, MBANDEDWG, MBOWED, MMESH2D, MSHAKERS, STRUM, STRUM2, STRUMFB, WIGGLE