Links

• Clifford Attractors -- this was the source of the main chaotic equation we used. Different values of the a, b, c andd parameters gave interestingly different sonic results.
  
• Peter De Jong Attractors -- turned out that this used the same equation as the "Clifford Attractors", but with even more values of the a, b, c andd parameters.
  
• bit-wise waveform creation -- this was the video I showed with the highly-compact bit-shifting algorithms used to generate interesting waveforms. We didn't try any of these because [gen~] doesn't have bit-wise operations, nor does it have 'char' (8-bit) data types. But it might be fun to try a few of these out, at least as a beginning-point for developing some new synthesis algorithms.
  

Class Patches, Discussion and Code

• week8-class-gen-patches.zip

• marlfilt4a.maxpat
  We modified the 'Marlon Feld' noise algorithm from last week's class to allow us to alter the filter coefficients in real-time. This version implemented changes to the high-pass filter coefficients only. It actually worked!
  
  
• marlfilt4b.maxpat
  This patch implemented real-time changes to the two low-pass filter coefficients as well as the high-pass coefficients. It didn't work so well... we discovered the joys of generating NaN numbers and how they blitz-out audio processing.
  
  
• clifford1.maxpat
  An implementation of the chaotic Clifford Attractor equation (see the link above) using [gen~] graphic patching. This is the basic attractor equation:

  x(n) = sin(a * y(n-1)) + c * cos(a * x(n-1))
  y(n) = sin(b * x(n-1)) + d * cos(b * y(n-1))
  	

  Note how the x(n) and y(n) outputs recurse back into the equation (through x(n-1) and y(n-1) variables) -- the [history] operator allows us to do this.

  We used the following sets of values for the a, b, c andd parameters:

  a = -1.4, b = 1.6, c = 1.0, d = 0.7 
  a = 1.1, b = -1.0, c = 1.0, d = 1.5 
  a = 1.6, b = -0.6, c = -1.2, d = 1.6 
  a = 1.7, b = 1.7, c = 0.06, d = 1.2 
  a = 1.3, b = 1.7, c = 0.5, d = 1.4 
  a = -2.24, b = 0.43, c = -0.65, d = -2.43
  	

  They are implemented as [param] messages.
  
  
• clifford2.maxpat
  A version of the 'clifford' [gen~] patch using [expr] objects for the chaos equations.
  
  
• clifford3.maxpat
  This version uses the [codebox] capability of [gen~] to rewrite the patch in a more text-y format. One warning: we had a minor problem because the [history] operator needs to be capitalized in [codebox]. Oh, computers!
  
  
• writebuffer.maxpat
  Very simple (and non-[gen~]) patch showing how we will write a waveform into a Max/MSP [buffer~] object using the multislider.
  
  
• wavetabley.maxpat
  This demonstrates how to read through a Max/MSP buffer "inside" [gen~]. It is a somewhat crude wavetable oscillator, though, as it doesn't have any interpolation or proper computation of frequency => sampling increment (the amount we 'skip' through the wavetable to get different frequencies, equal to si = freq * wavetable-size/sampling-rate). There are better [gen~] objects for doing wavetable synthesis (see [wave], for example).
  
  
• randwavetabley.maxpat
  A version of the wavetabley.maxpat that does a random buffer-lookup instead of a sequential lookup. Kind of silly, but what the heck