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Revar Desmera edited this page Nov 29, 2024 · 1 revision

LibFile: miscellaneous.scad

Miscellaneous modules that didn't fit in anywhere else, including bounding box, chain hull, extrusions, and minkowski based modules.

To use, add the following lines to the beginning of your file:

include <BOSL2/std.scad>

File Contents

  1. Section: Extrusion

  2. Section: Bounding Box

    • bounding_box() – Creates the smallest bounding box that contains all the children. [Geom]

  3. Section: Hull Based Modules

    • chain_hull() – Performs the union of hull operations between consecutive pairs of children. [Geom]

  4. Section: Minkowski and 3D Offset

Section: Extrusion

Module: extrude_from_to()

Synopsis: Extrudes 2D children between two points in 3D space. [Geom]

Topics: Extrusion, Miscellaneous

See Also: path_sweep(), path_extrude2d()

Usage:

  • extrude_from_to(pt1, pt2, [convexity=], [twist=], [scale=], [slices=]) 2D-CHILDREN;

Description:

Extrudes the 2D children linearly between the 3d points pt1 and pt2. The origin of the 2D children are placed on pt1 and pt2, and oriented perpendicular to the line between the points.

Arguments:

By Position What it does
pt1 starting point of extrusion.
pt2 ending point of extrusion.
By Name What it does
convexity max number of times a line could intersect a wall of the 2D shape being extruded.
twist number of degrees to twist the 2D shape over the entire extrusion length.
scale scale multiplier for end of extrusion compared the start.
slices Number of slices along the extrusion to break the extrusion into. Useful for refining twist extrusions.

Example 1:

extrude\_from\_to() Example 1 
include <BOSL2/std.scad>
extrude_from_to([0,0,0], [10,20,30], convexity=4, twist=360, scale=3.0, slices=40) {
    xcopies(3) circle(3, $fn=32);
}

Module: path_extrude2d()

Synopsis: Extrudes 2D children along a 2D path. [Geom]

Topics: Miscellaneous, Extrusion

See Also: path_sweep(), path_extrude()

Usage:

  • path_extrude2d(path, [caps=], [closed=], [s=], [convexity=]) 2D-CHILDREN;

Description:

Extrudes 2D children along the given 2D path, with optional rounded endcaps. It works by constructing straight sections corresponding to each segment of the path and inserting rounded joints at each corner. If the children are symmetric across the Y axis line then you can set caps=true to produce rounded caps on the ends of the profile. If you set caps to true for asymmetric children then incorrect caps will be generated.

Arguments:

By Position What it does
path The 2D path to extrude the geometry along.
By Name What it does
caps If true, caps each end of the path with a rounded copy of the children. Children must by symmetric across the Y axis, or results are wrong. Default: false
closed If true, connect the starting point of the path to the ending point. Default: false
convexity The max number of times a line could pass though a wall. Default: 10
s Mask size to use. Use a number larger than twice your object's largest axis. If you make this too large, it messes with centering your view. Default: The length of the diagonal of the path's bounding box.

Example 1:

path\_extrude2d() Example 1 
include <BOSL2/std.scad>
path = [
    each right(50, p=arc(d=100,angle=[90,180])),
    each left(50, p=arc(d=100,angle=[0,-90])),
];
path_extrude2d(path,caps=false) {
    fwd(2.5) square([5,6],center=true);
    fwd(6) square([10,5],center=true);
}



Example 2:

path\_extrude2d() Example 2 
include <BOSL2/std.scad>
path_extrude2d(arc(d=100,angle=[180,270]),caps=true)
    trapezoid(w1=10, w2=5, h=10, anchor=BACK);



Example 3:

path\_extrude2d() Example 3 
include <BOSL2/std.scad>
include <BOSL2/beziers.scad>
path = bezpath_curve([
    [-50,0], [-25,50], [0,0], [50,0]
]);
path_extrude2d(path, caps=false)
    trapezoid(w1=10, w2=3, h=5, anchor=BACK);



Example 4: Un-Closed Path

path\_extrude2d() Example 4 
include <BOSL2/std.scad>
$fn=16;
spath = star(id=15,od=35,n=5);
path_extrude2d(spath, caps=false, closed=false)
    move_copies([[-3.5,1.5],[0.0,3.0],[3.5,1.5]])
        circle(r=1.5);



Example 5: Complex Endcaps

path\_extrude2d() Example 5 
include <BOSL2/std.scad>
$fn=16;
spath = star(id=15,od=35,n=5);
path_extrude2d(spath, caps=true, closed=false)
    move_copies([[-3.5,1.5],[0.0,3.0],[3.5,1.5]])
        circle(r=1.5);



Module: path_extrude()

Synopsis: Extrudes 2D children along a 3D path. [Geom]

Topics: Paths, Extrusion, Miscellaneous

See Also: path_sweep(), path_extrude2d()

Usage:

  • path_extrude(path, [convexity], [clipsize]) 2D-CHILDREN;

Description:

Extrudes 2D children along a 3D path. This may be slow and can have problems with twisting.

Arguments:

By Position What it does
path Array of points for the bezier path to extrude along.
convexity Maximum number of walls a ray can pass through.
clipsize Increase if artifacts are left. Default: 100

Example 1:

path\_extrude() Example 1 
include <BOSL2/std.scad>
path = [ [0, 0, 0], [33, 33, 33], [66, 33, 40], [100, 0, 0], [150,0,0] ];
path_extrude(path) circle(r=10, $fn=6);

Module: cylindrical_extrude()

Synopsis: Extrudes 2D children outwards around a cylinder. [Geom]

Topics: Miscellaneous, Extrusion, Rotation

See Also: heightfield(), cylindrical_heightfield(), cyl()

Usage:

  • cylindrical_extrude(ir|id=, or|od=, [size=], [convexity=], [spin=], [orient=]) 2D-CHILDREN;

Description:

Chops the 2D children into rectangles and extrudes each rectangle as a facet around an approximate cylindrical shape. Uses $fn/$fa/$fs to control the number of facets. By default the calculation assumes that the children occupy in the X direction one revolution of the cylinder of specified radius/diameter and are not more than 1000 units tall (in the Y direction). If the children are in fact much smaller in width then this assumption is inefficient. If the children are wider then they will be truncated at one revolution. To address either of these problems you can set the size parameter. Note that the specified height isn't very important: it just needs to be larger than the actual height of the children, which is why it defaults to 1000. If you set size to a scalar then that only changes the X value and the Y value remains at the default of 1000.

When performing the wrap, the X=0 line of the children maps to the Y- axis and the facets are centered on the Y- axis. This is not consistent with how cylinder() creates its facets. If $fn is a multiple of 4 then the facets will line up with a cylinder. Otherwise you must rotate a cylinder by 90 deg in the case of $fn even or 90-360/$fn/2 if $fn is odd.

Arguments:

By Position What it does
ir The inner radius to extrude from.
or The outer radius to extrude to.
By Name What it does
od The outer diameter to extrude to.
id The inner diameter to extrude from.
size If a scalar, the width of the 2D children. If a vector, the [X,Y] size of the 2D children. Default: [2*PI*or,1000]
convexity The max number of times a line could pass though a wall. Default: 10
spin Amount in degrees to spin around cylindrical axis. Default: 0
orient The orientation of the cylinder to wrap around, given as a vector. Default: UP

Example 1: Basic example with defaults. This will run faster with large facet counts if you set size=100

cylindrical\_extrude() Example 1 
include <BOSL2/std.scad>
cylindrical_extrude(or=50, ir=45)
    text(text="Hello World!", size=10, halign="center", valign="center");

Example 2: Spin Around the Cylindrical Axis

cylindrical\_extrude() Example 2 
include <BOSL2/std.scad>
cylindrical_extrude(or=50, ir=45, spin=90)
    text(text="Hello World!", size=10, halign="center", valign="center");

Example 3: Orient to the Y Axis.

cylindrical\_extrude() Example 3 
include <BOSL2/std.scad>
cylindrical_extrude(or=40, ir=35, orient=BACK)
    text(text="Hello World!", size=10, halign="center", valign="center");

Example 4: You must give a size argument for this example where the child wraps fully around the cylinder

cylindrical\_extrude() Example 4 
include <BOSL2/std.scad>
cylindrical_extrude(or=27, ir=25, size=300, spin=-85)
    zrot(-10)text(text="This long text wraps around the cylinder.", size=10, halign="center", valign="center");

Section: Bounding Box

Module: bounding_box()

Synopsis: Creates the smallest bounding box that contains all the children. [Geom]

Topics: Miscellaneous, Bounds, Bounding Boxes

See Also: pointlist_bounds()

Usage:

  • bounding_box([excess],[planar]) CHILDREN;

Description:

Returns the smallest axis-aligned square (or cube) shape that contains all the 2D (or 3D) children given. The module children() must 3d when planar=false and 2d when planar=true, or you will get a warning of mixing dimension or scaling by 0.

Arguments:

By Position What it does
excess The amount that the bounding box should be larger than needed to bound the children, in each axis.
planar If true, creates a 2D bounding rectangle. Is false, creates a 3D bounding cube. Default: false

Example 1:

bounding\_box() Example 1 
include <BOSL2/std.scad>
module shapes() {
    translate([10,8,4]) cube(5);
    translate([3,0,12]) cube(2);
}
#bounding_box() shapes();
shapes();



Example 2:

bounding\_box() Example 2 
include <BOSL2/std.scad>
module shapes() {
    translate([10,8]) square(5);
    translate([3,0]) square(2);
}
#bounding_box(planar=true) shapes();
shapes();



Section: Hull Based Modules

Module: chain_hull()

Synopsis: Performs the union of hull operations between consecutive pairs of children. [Geom]

Topics: Miscellaneous

See Also: hull()

Usage:

  • chain_hull() CHILDREN;

Description:

Performs hull operations between consecutive pairs of children, then unions all of the hull results. This can be a very slow operation, but it can provide results that are hard to get otherwise.

Side Effects:

  • $idx is set to the index value of the first child of each hulling pair, and can be used to modify each child pair individually.
  • $primary is set to true when the child is the first in a chain pair.

Example 1:

chain\_hull() Example 1 
include <BOSL2/std.scad>
chain_hull() {
    cube(5, center=true);
    translate([30, 0, 0]) sphere(d=15);
    translate([60, 30, 0]) cylinder(d=10, h=20);
    translate([60, 60, 0]) cube([10,1,20], center=false);
}



Example 2: Using $idx and $primary

chain\_hull() Example 2 
include <BOSL2/std.scad>
chain_hull() {
    zrot(  0) right(100) if ($primary) cube(5+3*$idx,center=true); else sphere(r=10+3*$idx);
    zrot( 45) right(100) if ($primary) cube(5+3*$idx,center=true); else sphere(r=10+3*$idx);
    zrot( 90) right(100) if ($primary) cube(5+3*$idx,center=true); else sphere(r=10+3*$idx);
    zrot(135) right(100) if ($primary) cube(5+3*$idx,center=true); else sphere(r=10+3*$idx);
    zrot(180) right(100) if ($primary) cube(5+3*$idx,center=true); else sphere(r=10+3*$idx);
}

Section: Minkowski and 3D Offset

Module: minkowski_difference()

Synopsis: Removes diff shapes from base shape surface. [Geom]

Topics: Miscellaneous

See Also: offset3d()

Usage:

  • minkowski_difference() { BASE; DIFF1; DIFF2; ... }

Description:

Takes a 3D base shape and one or more 3D diff shapes, carves out the diff shapes from the surface of the base shape, in a way complementary to how minkowski() unions shapes to the surface of its base shape.

Arguments:

By Position What it does
planar If true, performs minkowski difference in 2D. Default: false (3D)

Example 1:

minkowski\_difference() Example 1 
include <BOSL2/std.scad>
minkowski_difference() {
    union() {
        cube([120,70,70], center=true);
        cube([70,120,70], center=true);
        cube([70,70,120], center=true);
    }
    sphere(r=10);
}



Module: offset3d()

Synopsis: Expands or contracts the surface of a 3D object. [Geom]

Topics: Miscellaneous

See Also: minkowski_difference(), round3d()

Usage:

  • offset3d(r, [size], [convexity]) CHILDREN;

Description:

Expands or contracts the surface of a 3D object by a given amount. This is very, very slow. No really, this is unbearably slow. It uses minkowski(). Use this as a last resort. This is so slow that no example images will be rendered.

Arguments:

By Position What it does
r Radius to expand object by. Negative numbers contract the object.
size Maximum size of object to be contracted, given as a scalar. Default: 100
convexity Max number of times a line could intersect the walls of the object. Default: 10

Module: round3d()

Synopsis: Rounds arbitrary 3d objects. [Geom]

Topics: Rounding, Miscellaneous

See Also: offset3d(), minkowski_difference()

Usage:

  • round3d(r) CHILDREN;
  • round3d(or) CHILDREN;
  • round3d(ir) CHILDREN;
  • round3d(or, ir) CHILDREN;

Description:

Rounds arbitrary 3D objects. Giving r rounds all concave and convex corners. Giving just ir rounds just concave corners. Giving just or rounds convex corners. Giving both ir and or can let you round to different radii for concave and convex corners. The 3D object must not have any parts narrower than twice the or radius. Such parts will disappear. This is an extremely slow operation. I cannot emphasize enough just how slow it is. It uses minkowski() multiple times. Use this as a last resort. This is so slow that no example images will be rendered.

Arguments:

By Position What it does
r Radius to round all concave and convex corners to.
or Radius to round only outside (convex) corners to. Use instead of r.
ir Radius to round only inside (concave) corners to. Use instead of r.

Home – Table of Contents – Functions Index – Topics – Cheat Sheet – Tutorials

Indices

Table of Contents
Function Index
Topics Index
Cheat Sheet
Tutorials

List of Files:

Basic Modeling:

Advanced Modeling:

Math:

Data Management:

Threaded Parts:

Parts:

Footnotes:

STD = Included in std.scad

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