dotSCAD/docs/lib3x-rail_extruded_sections.md

rail_extruded_sections

Given a rail with the first point at the outline of a shape. This function uses the rail to extrude the shape and returns all sections in the reversed order of the rail. Combined with the sweep module, you can create rail extrusion.

In order to control extrusion easily, I suggest using [x, 0, 0] as the first point and keeping y = 0 while building the rail.

Since: 3.2

Parameters

• shape_pts : A list of points represent a shape.
• rail : A list of points represent the edge path.

Examples

use <hull_polyline3d.scad>;
use <shape_taiwan.scad>;
use <rail_extruded_sections.scad>;
use <sweep.scad>;

taiwan = shape_taiwan(100);
fst_pt = [13, 0, 0];

rail = [
	fst_pt,
	fst_pt + [0, 0, 10],
	fst_pt + [10, 0, 20],
	fst_pt + [8, 0, 30],
	fst_pt + [12, 0, 40],
	fst_pt + [0, 0, 50],
	fst_pt + [0, 0, 60]
];

#hull_polyline3d(rail);
sweep(rail_extruded_sections(taiwan, rail));

use <hull_polyline3d.scad>;
use <shape_taiwan.scad>;
use <rail_extruded_sections.scad>;
use <sweep.scad>;
use <bezier_curve.scad>;


taiwan = shape_taiwan(100);
fst_pt = [13, 0, 0];

rail = bezier_curve(0.05, [
	fst_pt,
	fst_pt + [0, 0, 10],
	fst_pt + [10, 0, 20],
	fst_pt + [8, 0, 30],
	fst_pt + [12, 0, 40],
	fst_pt + [0, 0, 50],
	fst_pt + [0, 0, 60]
]);

#hull_polyline3d(rail);
sweep(rail_extruded_sections(taiwan, rail));

use <shape_taiwan.scad>;
use <rail_extruded_sections.scad>;
use <sweep.scad>;
use <bezier_curve.scad>;
use <ptf/ptf_rotate.scad>;

taiwan = shape_taiwan(100);
fst_pt = [13, 0, 0];

rail = bezier_curve(0.05, [
	fst_pt,
	fst_pt + [0, 0, 10],
	fst_pt + [10, 0, 20],
	fst_pt + [8, 0, 30],
	fst_pt + [12, 0, 40],
	fst_pt + [0, 0, 50],
	fst_pt + [0, 0, 60]
]);

leng = len(rail);
twist = -90;
twist_step = twist / leng;
sections = rail_extruded_sections(taiwan, rail);

rotated_sections = [
	for(i = [0:leng - 1]) 
	[
		for(p = sections[i]) 
			ptf_rotate(p, twist_step * i)        
	]
];

sweep(rotated_sections);

use <hull_polyline3d.scad>;
use <shape_taiwan.scad>;
use <rail_extruded_sections.scad>;
use <sweep.scad>;
use <ptf/ptf_rotate.scad>;

taiwan = shape_taiwan(100);

/* 
    You can use any point as the first point of the edge path.
	Just remember that your edge path radiates from the origin.
*/
fst_pt = [taiwan[0][0], taiwan[0][1], 0];//[13, 0, 0];
a = atan2(fst_pt[1], fst_pt[0]);
rail = [
	fst_pt,
	fst_pt + ptf_rotate([0, 0, 10], a),
	fst_pt + ptf_rotate([10, 0, 20], a),
	fst_pt + ptf_rotate([8, 0, 30], a),
	fst_pt + ptf_rotate([10, 0, 40], a),
	fst_pt + ptf_rotate([0, 0, 50], a),
	fst_pt + ptf_rotate([0, 0, 60], a)
];

#hull_polyline3d(rail);
sweep(rail_extruded_sections(taiwan, rail));