dotSCAD/docs/lib3x-sweep.md

sweep

This module sweeps multiple cross-sections to create a 3D object. For example, imagine that you have the following cross-sections:

This module sweeps them to create a 3D object:

When using this module, you should use points to represent a cross section. The points must be counter-clockwise indexes. For example:

If your cross section is hollow, set the triangles parameter to "HOLLOW" and index the points as the following:

You can cut triangles by yourself. For example, the above shape can be cut into triangles such as:

The indexes of the above triangles is:

[
	[0, 3, 1],
	[1, 3, 4],
	[1, 4, 2],
	[2, 4, 5],
	[2, 5, 0],
	[0, 5, 3]
]

Since: 2.3

Parameters

• sections : A list of cross-sections. Each cross-section is represented by points. See the example below.
• triangles : "SOLID" (default), "HOLLOW", or user-defined indexes. See example below.

Examples

use <ptf/ptf_rotate.scad>
use <sweep.scad>

section1 = [
	[20, 0, 0],
	[18, 9, 0],
	[15, 10, 0],
	[10, 0, 0]
];

// spin section1
sections = [
	for(i = [0:55]) 
	[
		for(p = section1)
			let(pt = ptf_rotate(p, [90, 0, 10 * i]))
			[pt.x, pt.y , pt.z + i]
	]
];

sweep(sections);

use <ptf/ptf_rotate.scad>
use <sweep.scad>

section1 = [
    // outer
	[20, 0, 0],
	[18, 9, 0],
	[15, 10, 0],
	[10, 0, 0],
    // inner
    [18, 2, 0],
    [17, 7, 0],
    [15, 7, 0],
    [12, 2, 0]
];

// spin section1
sections = [
    for(i = [0:55]) 
	[
		for(p = section1)
			let(pt = ptf_rotate(p, [90, 0, 10 * i]))
			[pt.x, pt.y , pt.z + i]
	]
];
    
sweep(sections, "HOLLOW");

use <ptf/ptf_rotate.scad>
use <sweep.scad>

section1 = [
    // outer
    [30, 0, 0],
    [15, 10, 0],
    [10, 0, 0],
    // inner
    [26, 1, 0],
    [15, 8, 0],
    [12, 1, 0],        
];

// spin section1
sections = [
    for(i = [0:55]) 
	[
		for(p = section1)
			let(pt = ptf_rotate(p, [90, 0, 10 * i]))
			[pt.x, pt.y , pt.z + i]
	]
];
    
sweep(
   sections = sections, 
   triangles = [
        [0, 3, 1],
        [1, 3, 4],
        [1, 4, 2],
        [2, 4, 5],
        [2, 5, 0],
        [0, 5, 3]
    ]
);