blob57

  # name of the blob
  project = "blob39";  
   
   # function at origin must be <0, and >0 far enough away.  w=0 defines the surface
function w = f(x2,y2,z2,c,r)  
   x = (x2-c(1))/r(1);
   y=(y2-c(2))/r(2);
   z=(z2-c(3))/r(3);

   px1 = 8.0;  py1 =0; # position of swirl 
   t1 = 2.5;  # effective width of swirl
   angle1 = 4; # angle of swirl at the center
   one_mat = 0*x+1; # matrix of the right size, but all elements are set to 1.0
   an = angle1*(one_mat./(1.0+((x-px1)/t1).^2+((y-py1)/t1).^2));
   x3=px1+(x-px1).*cos(an)-(y-py1).*sin(an);
   y3=py1+(y-py1).*cos(an)+(x-px1).*sin(an);
   z3=z;

   w=((x3/3).^2+(y3).^2+(z3.*(1.0+0.0*x3)).^2)-6; # ellipsoid

  endfunction;

  c_outer = [0,0,0];
  r_outer = [14,18,10]; 

 xmin = -150;  # avoid the origin because the inverse of the gradient is NaN there
 xmax = 150;

  step = 4;  # grid pitch in mm  start with 4mm to see the shape quickly.  Once you have it just right, change to 2mm for printing

  source("../octave/func2stl_v01.m");  # do all the calculations