sweep

gistfile1.txt

use <list-comprehension/skin.scad>
use <list-comprehension/extrusion.scad>

use <scad-utils/transformations.scad>
use <scad-utils/lists.scad>
use <scad-utils/shapes.scad>

use <dotSCAD/bezier_curve.scad>

o=0;

points = [
  [-50,-200,0],
  [0,-20,0],
  [0,30,0],
  [110,40,30],
  [110,40,80],
];

function _circle(r) = [ for (a = [0 : 10 : 360]) [
  r * cos(a), r * sin(a)
]];

function _rect(size) = [
  [-size[0],-size[1]],
  [+size[0],-size[1]],
  [+size[0],+size[1]],
  [-size[0],+size[1]],
];

path = bezier_curve(0.11, points);
//path = [ for (p=points) p ];

/*
function profile(t) =
  (1-t) * augment_profile(to_3d(_rect([70+2*o,25+2*o])),4) +
      t * augment_profile(to_3d(_circle($fn=64,r=55/2+o)),4);
*/

function profile(t) =
  0 * _rect([70+2*o,25+2*o]) +
  1 * _circle(55/2+o);

/*
function profile(t) =
  (1-t) * _rect([70+2*o,25+2*o]) +
  t     * _circle(55/2+o);
*/

/*
function profile(t) =
  _rect([70+2*o,25+2*o]);
*/

/*
function profile(t) =
  _circle($fn=64,r=55/2+o);
*/
    
  total = len(path)-1;
  trans = [ for (i=[0:len(path)-1]) transform(
    translation(path[i]) * rotation([-90*(1-i/total),0,0])
  , profile(1)) ];
//  , profile(i/total)) ];

  skin(trans);

Somewhat like this but...

I kind of got it working using a skin()