
Demakein
======== 

http://www.logarithmic.net/pfh/design

Paul Harrison - pfh@logarithmic.net


Demakein is a set of Python tools for designing and making woodwind 
instruments.

This generally consists of two stages:

- The "design" stage is a numerical optimization that chooses the bore 
  shape and the finger hole placement, size, and depth necessary for
  the instrument to produce the correct notes for a given set of
  fingerings.

- The "make" stage takes a design and turns it into a 3D object, then 
  then cuts the object into pieces that can be CNC-milled or 3D-printed.

Demakein can either be used via the command "demakein" or as a
library in Python. Demakein has been designed to be extensible,
and I hope you will find it relatively easy to write code to
create your own novel instruments. You can either create subclasses
of existing classes in order to tweak a few parameters, or create 
wholly new classes using existing examples as a template.


Requirements
============

Python 2
- Linux:
    Use your package manager to install Python 2 and pip.
- OS X
    Reported to be possible, however I can't give exact instructions.
- Windows:
    This may or may not work:
    http://docs.python-guide.org/en/latest/starting/install/win/
    - install python 2 using the MSI package
    - install distribute using the linked script
    - install pip using easy_install
    I'm sorry this is so involved.
    
The "design" tools require nesoni. They should work on all platforms that
Python runs on.

- nesoni

  pip install nesoni

The "make" tools additionally require CGAL and associated paraphenalia.
I have only tested this on Linux, but I'm told it's possible on OS X as well.

- g++
- cmake
- libcffi
- CGAL

  apt-get install g++ cmake libffi-dev libcgal-dev

- cffi

  pip install cffi


Installation
============

Easy way:

  pip install demakein

From source: Download and untar tarball then

  python setup.py install

You can then run program by typing

  demakein

or

  python -m demakein


Note:
If you know how to set it up, using PyPy will let Demakein run considerably faster.


Examples
========

Create a small flute:

  demakein design-straight-folk-flute: myflute --transpose 12
  
  demakein make-flute: myflute

Files are created in a directory called myflute.

We've just made STL files for 3D printing. How about if we want 
to CNC-mill the flute?

  demakein make-flute: myflute --mill yes --open yes --prefix milling


If you want to create your own custom instruments, you can create
subclasses of the instruments provided. Some examples of how to do
this can be found in the "examples" directory.


Instrument design tools are subclasses of demakein.design.Instrument_designer.
These tools define a set of class attributes that constrain the instrument design.

closed_top 
- bool
  Is the top of the instrument closed? 
  Reeds and brass-style mouthpieces are effectively closed.
  A ney has an open end.
  A flute might be approximated as an open end, or the embouchure
  hole treated as a hole and the end set to closed.

inital_length
- float
  Length of the instrument at the start of the optimization.
  Automatically adjusted based on --transpose parameter.
  Just provide a roughly reasonable value, 
  eg using demakein.design.wavelength function

n_holes
- int
  Number of finger holes.
  
fingerings
- list of tuples (note, [ 0/1,... ])
  Desired fingering patterns to produce each desired note.
  <note> is automatically adjusted by --transpose parameter.
  The list starts from the bottom of the instrument.
  Not all fingering schemes are physically possible,
  this may require some experimentation.

max_hole_diameters
- list of n_holes floats
  Maximum allowed finger hole diameters.

min_hole_diameters
- list of n_holes floats
  Minimum allowed finger hole diameters.

min_hole_spacing
- list of n_holes-1 floats
  Minimum space between finger holes in mm.

top_clearance_fraction
bottom_clearance_fraction
- Minimum distance of top/bottom hole from top/bottom of instrument,
  as a fraction of the instrument length.

balance
- list of n_holes-2 floats or Nones
  Values should be in the range zero to one.
  Smaller values force the spacing between successive holes to be more similar.

hole_angles
- list of n_holes floats
  Vertical angle of each hole.
  Angled holes may allow more comfortable hole spacing.

inner_diameters
- list of floats
  The first element is the bore diameter at the base of the instrument.
  The last element is the bore diameter at the top of the instrument.
  The bore is piecewise linear,
  intervening elements are bore diameters boundaries between pieces (kinks).
  Exact placement is subject to numerical optimization.
  
initial_inner_fractions
- list of len(inner_diameters)-2 floats
  Initial positions of kinks in the bore.

min_inner_fraction_sep
- list of len(inner_diameters)-1 floats
  Minimum size of each linear segment of the bore,
  as a fraction of the overall length.

outer_diameters
initial_outer_fractions
min_outer_fraction_sep
- As for inner_diameters, 
  but defining the shape of the outside of the instrument
  (hence the depth of each finger hole).






