BOSL2/miscellaneous.scad
Adrian Mariano c6e58b926b doc fix
2024-06-22 22:58:52 -04:00

616 lines
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OpenSCAD

//////////////////////////////////////////////////////////////////////
// LibFile: miscellaneous.scad
// Miscellaneous modules that didn't fit in anywhere else, including
// bounding box, chain hull, extrusions, and minkowski based
// modules.
// Includes:
// include <BOSL2/std.scad>
// FileGroup: Basic Modeling
// FileSummary: Extrusion, bounding box, chain hull and minkowski-based transforms.
// FileFootnotes: STD=Included in std.scad
//////////////////////////////////////////////////////////////////////
// Section: Extrusion
// Module: extrude_from_to()
// Synopsis: Extrudes 2D children between two points in 3D space.
// SynTags: 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:
// pt1 = starting point of extrusion.
// pt2 = ending point of extrusion.
// ---
// 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(FlatSpin,VPD=200,VPT=[0,0,15]):
// extrude_from_to([0,0,0], [10,20,30], convexity=4, twist=360, scale=3.0, slices=40) {
// xcopies(3) circle(3, $fn=32);
// }
module extrude_from_to(pt1, pt2, convexity, twist, scale, slices) {
req_children($children);
check =
assert(is_vector(pt1),"First point must be a vector")
assert(is_vector(pt2),"Second point must be a vector");
pt1 = point3d(pt1);
pt2 = point3d(pt2);
rtp = xyz_to_spherical(pt2-pt1);
attachable()
{
translate(pt1) {
rotate([0, rtp[2], rtp[1]]) {
if (rtp[0] > 0) {
linear_extrude(height=rtp[0], convexity=convexity, center=false, slices=slices, twist=twist, scale=scale) {
children();
}
}
}
}
union();
}
}
// Module: path_extrude2d()
// Synopsis: Extrudes 2D children along a 2D path.
// SynTags: 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:
// path = The 2D path to extrude the geometry along.
// ---
// 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:
// 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:
// path_extrude2d(arc(d=100,angle=[180,270]),caps=true)
// trapezoid(w1=10, w2=5, h=10, anchor=BACK);
// Example:
// 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: Un-Closed Path
// $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: Complex Endcaps
// $fn=16;
// spath = star(id=15,od=35,n=5);
// path_extrude2d(spath, caps=true, closed=false)
// move_copies([[-3.5,1.5],[0.0,3.0],[3.5,1.5]])
// circle(r=1.5);
module path_extrude2d(path, caps=false, closed=false, s, convexity=10) {
req_children($children);
extra_ang = 0.1; // Extra angle for overlap of joints
check =
assert(caps==false || closed==false, "Cannot have caps on a closed extrusion")
assert(is_path(path,2));
path = deduplicate(path);
s = s!=undef? s :
let(b = pointlist_bounds(path))
norm(b[1]-b[0]);
check2 = assert(is_finite(s));
L = len(path);
attachable(){
union(){
for (i = [0:1:L-(closed?1:2)]) {
seg = select(path, i, i+1);
segv = seg[1] - seg[0];
seglen = norm(segv);
translate((seg[0]+seg[1])/2) {
rot(from=BACK, to=segv) {
difference() {
xrot(90) {
linear_extrude(height=seglen, center=true, convexity=convexity) {
children();
}
}
if (closed || i>0) {
pt = select(path, i-1);
pang = v_theta(rot(from=-segv, to=RIGHT, p=pt - seg[0]));
fwd(seglen/2+0.01) zrot(pang/2) cube(s, anchor=BACK);
}
if (closed || i<L-2) {
pt = select(path, i+2);
pang = v_theta(rot(from=segv, to=RIGHT, p=pt - seg[1]));
back(seglen/2+0.01) zrot(pang/2) cube(s, anchor=FWD);
}
}
}
}
}
for (t=triplet(path,wrap=closed)) {
ang = -(180-vector_angle(t)) * sign(_point_left_of_line2d(t[2],[t[0],t[1]]));
delt = point3d(t[2] - t[1]);
if (ang!=0)
translate(t[1]) {
frame_map(y=delt, z=UP)
rotate(-sign(ang)*extra_ang/2)
rotate_extrude(angle=ang+sign(ang)*extra_ang)
if (ang<0)
right_half(planar=true) children();
else
left_half(planar=true) children();
}
}
if (caps) {
bseg = select(path,0,1);
move(bseg[0])
rot(from=BACK, to=bseg[0]-bseg[1])
rotate_extrude(angle=180)
right_half(planar=true) children();
eseg = select(path,-2,-1);
move(eseg[1])
rot(from=BACK, to=eseg[1]-eseg[0])
rotate_extrude(angle=180)
right_half(planar=true) children();
}
}
union();
}
}
// Module: path_extrude()
// Synopsis: Extrudes 2D children along a 3D path.
// SynTags: 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:
// 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(FlatSpin,VPD=600,VPT=[75,16,20]):
// path = [ [0, 0, 0], [33, 33, 33], [66, 33, 40], [100, 0, 0], [150,0,0] ];
// path_extrude(path) circle(r=10, $fn=6);
module path_extrude(path, convexity=10, clipsize=100) {
req_children($children);
rotmats = cumprod([
for (i = idx(path,e=-2)) let(
vec1 = i==0? UP : unit(path[i]-path[i-1], UP),
vec2 = unit(path[i+1]-path[i], UP)
) rot(from=vec1,to=vec2)
]);
// This adds a rotation midway between each item on the list
interp = rot_resample(rotmats,n=2,method="count");
epsilon = 0.0001; // Make segments ever so slightly too long so they overlap.
ptcount = len(path);
attachable(){
for (i = [0:1:ptcount-2]) {
pt1 = path[i];
pt2 = path[i+1];
dist = norm(pt2-pt1);
T = rotmats[i];
difference() {
translate(pt1) {
multmatrix(T) {
down(clipsize/2/2) {
if ((dist+clipsize/2) > 0) {
linear_extrude(height=dist+clipsize/2, convexity=convexity) {
children();
}
}
}
}
}
translate(pt1) {
hq = (i > 0)? interp[2*i-1] : T;
multmatrix(hq) down(clipsize/2+epsilon) cube(clipsize, center=true);
}
translate(pt2) {
hq = (i < ptcount-2)? interp[2*i+1] : T;
multmatrix(hq) up(clipsize/2+epsilon) cube(clipsize, center=true);
}
}
}
union();
}
}
// Module: cylindrical_extrude()
// Synopsis: Extrudes 2D children outwards around a cylinder.
// SynTags: 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 `$fn` is odd.
// Arguments:
// ir = The inner radius to extrude from.
// or = The outer radius to extrude to.
// ---
// od = The outer diameter to extrude to.
// id = The inner diameter to extrude from.
// size = If a scalar, the width of the 2D children. If a vector, the [X,Y] size of the 2D children. Default: [`2*PI*or`,1000]
// convexity = The max number of times a line could pass though a wall. Default: 10
// spin = Amount in degrees to spin around cylindrical axis. Default: 0
// orient = The orientation of the cylinder to wrap around, given as a vector. Default: UP
// Example: Basic example with defaults. This will run faster with large facet counts if you set `size=100`
// cylindrical_extrude(or=50, ir=45)
// text(text="Hello World!", size=10, halign="center", valign="center");
// Example: Spin Around the Cylindrical Axis
// cylindrical_extrude(or=50, ir=45, spin=90)
// text(text="Hello World!", size=10, halign="center", valign="center");
// Example: Orient to the Y Axis.
// cylindrical_extrude(or=40, ir=35, orient=BACK)
// text(text="Hello World!", size=10, halign="center", valign="center");
// Example(Med): You must give a size argument for this example where the child wraps fully around the cylinder
// cylindrical_extrude(or=27, ir=25, size=300, spin=-85)
// zrot(-10)text(text="This long text wraps around the cylinder.", size=10, halign="center", valign="center");
module cylindrical_extrude(ir, or, od, id, size, convexity=10, spin=0, orient=UP) {
req_children($children);
ir = get_radius(r=ir,d=id);
or = get_radius(r=or,d=od);
check2 = assert(all_positive([ir,or]), "Must supply positive inner and outer radius or diameter");
circumf = 2 * PI * or;
size = is_undef(size) ? [circumf, 1000]
: is_num(size) ? [size, 1000]
: size;
check1 = assert(is_vector(size,2) && all_positive(size), "Size must be a positive number or 2-vector");
sides = segs(or);
step = circumf / sides;
steps = ceil(size.x / step);
scalefactor = sides/PI*sin(180/sides); // Scale from circle to polygon, which has shorter length
attachable() {
rot(from=UP, to=orient) rot(spin) {
for (i=[0:1:steps-1]) {
x = (i+0.5-steps/2) * step;
zrot(360 * x / circumf) {
fwd(or*cos(180/sides)) {
xrot(-90) {
linear_extrude(height=or-ir, scale=[ir/or,1], center=false, convexity=convexity) {
yflip()
xscale(scalefactor)
intersection() {
left(x) children();
rect([quantup(step,pow(2,-15)),size.y]);
}
}
}
}
}
}
}
union();
}
}
//////////////////////////////////////////////////////////////////////
// Section: Bounding Box
//////////////////////////////////////////////////////////////////////
// Module: bounding_box()
// Synopsis: Creates the smallest bounding box that contains all the children.
// SynTags: 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:
// 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(3D):
// module shapes() {
// translate([10,8,4]) cube(5);
// translate([3,0,12]) cube(2);
// }
// #bounding_box() shapes();
// shapes();
// Example(2D):
// module shapes() {
// translate([10,8]) square(5);
// translate([3,0]) square(2);
// }
// #bounding_box(planar=true) shapes();
// shapes();
module bounding_box(excess=0, planar=false) {
// a 3d (or 2d when planar=true) approx. of the children projection on X axis
module _xProjection() {
if (planar) {
projection()
rotate([90,0,0])
linear_extrude(1, center=true)
hull()
children();
} else {
xs = excess<.1? 1: excess;
linear_extrude(xs, center=true)
projection()
rotate([90,0,0])
linear_extrude(xs, center=true)
projection()
hull()
children();
}
}
// a bounding box with an offset of 1 in all axis
module _oversize_bbox() {
if (planar) {
minkowski() {
_xProjection() children(); // x axis
rotate(-90) _xProjection() rotate(90) children(); // y axis
}
} else {
minkowski() {
_xProjection() children(); // x axis
rotate(-90) _xProjection() rotate(90) children(); // y axis
rotate([0,-90,0]) _xProjection() rotate([0,90,0]) children(); // z axis
}
}
}
// offsets a cube by `excess`
module _shrink_cube() {
intersection() {
translate((1-excess)*[ 1, 1, 1]) children();
translate((1-excess)*[-1,-1,-1]) children();
}
}
req_children($children);
attachable(){
if(planar) {
offset(excess-1/2) _oversize_bbox() children();
} else {
render(convexity=2)
if (excess>.1) {
_oversize_bbox() children();
} else {
_shrink_cube() _oversize_bbox() children();
}
}
union();
}
}
//////////////////////////////////////////////////////////////////////
// Section: Hull Based Modules
//////////////////////////////////////////////////////////////////////
// Module: chain_hull()
// Synopsis: Performs the union of hull operations between consecutive pairs of children.
// SynTags: Geom
// Topics: Miscellaneous
// See Also: hull()
// Usage:
// chain_hull() CHILDREN;
//
// Description:
// Performs hull operations between consecutive pairs of children,
// then unions all of the hull results. This can be a very slow
// operation, but it can provide results that are hard to get
// otherwise.
//
// Side Effects:
// `$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.
// `$primary` is set to true when the child is the first in a chain pair.
//
// Example:
// chain_hull() {
// cube(5, center=true);
// translate([30, 0, 0]) sphere(d=15);
// translate([60, 30, 0]) cylinder(d=10, h=20);
// translate([60, 60, 0]) cube([10,1,20], center=false);
// }
// Example: Using `$idx` and `$primary`
// chain_hull() {
// zrot( 0) right(100) if ($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);
// }
module chain_hull()
{
req_children($children);
attachable(){
if ($children == 1) {
children();
}
else {
for (i =[1:1:$children-1]) {
$idx = i;
hull() {
let($primary=true) children(i-1);
let($primary=false) children(i);
}
}
}
union();
}
}
//////////////////////////////////////////////////////////////////////
// Section: Minkowski and 3D Offset
//////////////////////////////////////////////////////////////////////
// Module: minkowski_difference()
// Synopsis: Removes diff shapes from base shape surface.
// SynTags: Geom
// Topics: Miscellaneous
// See Also: offset3d()
// Usage:
// minkowski_difference() { BASE; DIFF1; DIFF2; ... }
// Description:
// Takes a 3D base shape and one or more 3D diff shapes, carves out the diff shapes from the
// surface of the base shape, in a way complementary to how `minkowski()` unions shapes to the
// surface of its base shape.
// Arguments:
// planar = If true, performs minkowski difference in 2D. Default: false (3D)
// Example:
// minkowski_difference() {
// union() {
// cube([120,70,70], center=true);
// cube([70,120,70], center=true);
// cube([70,70,120], center=true);
// }
// sphere(r=10);
// }
module minkowski_difference(planar=false) {
req_children($children);
attachable(){
difference() {
bounding_box(excess=0, planar=planar) children(0);
render(convexity=20) {
minkowski() {
difference() {
bounding_box(excess=1, planar=planar) children(0);
children(0);
}
for (i=[1:1:$children-1]) children(i);
}
}
}
union();
}
}
// Module: offset3d()
// Synopsis: Expands or contracts the surface of a 3D object.
// SynTags: Geom
// Topics: Miscellaneous
// See Also: minkowski_difference(), round3d()
// Usage:
// offset3d(r, [size], [convexity]) CHILDREN;
// Description:
// Expands or contracts the surface of a 3D object by a given amount. This is very, very slow.
// No really, this is unbearably slow. It uses `minkowski()`. Use this as a last resort.
// This is so slow that no example images will be rendered.
// Arguments:
// r = Radius to expand object by. Negative numbers contract the object.
// size = Maximum size of object to be contracted, given as a scalar. Default: 100
// convexity = Max number of times a line could intersect the walls of the object. Default: 10
module offset3d(r, size=100, convexity=10) {
req_children($children);
n = quant(max(8,segs(abs(r))),4);
attachable(){
if (r==0) {
children();
} else if (r>0) {
render(convexity=convexity)
minkowski() {
children();
sphere(r, $fn=n);
}
} else {
size2 = size * [1,1,1];
size1 = size2 * 1.02;
render(convexity=convexity)
difference() {
cube(size2, center=true);
minkowski() {
difference() {
cube(size1, center=true);
children();
}
sphere(-r, $fn=n);
}
}
}
union();
}
}
// Module: round3d()
// Synopsis: Rounds arbitrary 3d objects.
// SynTags: Geom
// Topics: Rounding, Miscellaneous
// See Also: offset3d(), minkowski_difference()
// Usage:
// round3d(r) CHILDREN;
// round3d(or) CHILDREN;
// round3d(ir) CHILDREN;
// round3d(or, ir) CHILDREN;
// Description:
// Rounds arbitrary 3D objects. Giving `r` rounds all concave and convex corners. Giving just `ir`
// rounds just concave corners. Giving just `or` rounds convex corners. Giving both `ir` and `or`
// can let you round to different radii for concave and convex corners. The 3D object must not have
// any parts narrower than twice the `or` radius. Such parts will disappear. This is an *extremely*
// slow operation. I cannot emphasize enough just how slow it is. It uses `minkowski()` multiple times.
// Use this as a last resort. This is so slow that no example images will be rendered.
// Arguments:
// r = Radius to round all concave and convex corners to.
// or = Radius to round only outside (convex) corners to. Use instead of `r`.
// ir = Radius to round only inside (concave) corners to. Use instead of `r`.
module round3d(r, or, ir, size=100)
{
req_children($children);
or = get_radius(r1=or, r=r, dflt=0);
ir = get_radius(r1=ir, r=r, dflt=0);
attachable(){
offset3d(or, size=size)
offset3d(-ir-or, size=size)
offset3d(ir, size=size)
children();
union();
}
}
// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap