dotSCAD/docs/lib-cross_sections.md

cross_sections

Given a starting cross-section, points and angles along the path, this function will return all cross-sections. Combined with the polysections module, you can create a specific path extrusion.

It depends on the rotate_p function. Remember to include "rotate_p.scad".

Parameters

• shape_pts: A list of points represent a shape. See the example below.
• path_pts : A list of points represent the path.
• angles : A list of angles. Each point should have a corresponding angle used to rotate the 2D shape.
• twist: The number of degrees of through which the shape is extruded.
• scale : Scales the 2D shape by this value over the length of the extrusion. Scale can be a scalar or a vector.

Examples

include <rotate_p.scad>;
include <polysections.scad>;
include <cross_sections.scad>;
include <archimedean_spiral.scad>;

shape_pts = [
	[-2, -10],
	[-2, 10],
	[2, 10],
	[2, -10]
];

pts_angles = archimedean_spiral(
	arm_distance = 20,
	init_angle = 180,
	point_distance = 5,
	num_of_points = 100 
); 

pts = [for(pt_angle = pts_angles) pt_angle[0]];
angles = [
	for(i = [0:len(pts_angles) - 1]) [90, 0, pts_angles[i][1]]
];

polysections(
	cross_sections(shape_pts, pts, angles, twist = 180, scale = 0.1)
);