scad/MCAD/curves.scad

   1 // Parametric curves, to be used as paths
   2 // Licensed under the MIT license.
   3 // © 2010 by Elmo Mäntynen
   4 use <math.scad>
   5 include <constants.scad>
   6
   7
   8
   9 /* A circular helix of radius a and pitch 2πb is described by the following parametrisation:
  10 x(t) = a*cos(t),
  11 y(t) = a*sin(t),
  12 z(t) = b*t
  13 */
  14
  15
  16 function b(pitch) = pitch/(TAU);
  17 function t(pitch, z) = z/b(pitch);
  18
  19 function helix_curve(pitch, radius, z) =
  20     [radius*cos(deg(t(pitch, z))), radius*sin(deg(t(pitch, z))), z];
  21