diff --git a/shapes2d.scad b/shapes2d.scad index 40283fa..b57cc11 100644 --- a/shapes2d.scad +++ b/shapes2d.scad @@ -1191,12 +1191,16 @@ module jittered_poly(path, dist=1/512) { // Description: // Makes a 2D teardrop shape. Useful for extruding into 3D printable holes. Uses "intersect" style anchoring. // The cap_h parameter truncates the top of the teardrop. If cap_h is taller than the untruncated form then -// the result will be the full, untruncated shape. +// the result will be the full, untruncated shape. The segments of the bottom section of the teardrop are +// calculated to be the same as a circle or cylinder when rotated 90 degrees. (Note that this agreement is poor when `$fn=6` or `$fn=7`. +// If `$fn` is a multiple of four then the teardrop will reach its extremes on all four axes. The circum option +// produces a teardrop that circumscribes the circle; in this case set `realign=true` to get a teardrop that meets its internal extremes +// on the axes. // // Usage: As Module // teardrop2d(r/d=, [ang], [cap_h]) [ATTACHMENTS]; // Usage: As Function -// path = teardrop2d(r/d=, [ang], [cap_h]); +// path = teardrop2d(r|d=, [ang], [cap_h]); // // Topics: Shapes (2D), Paths (2D), Path Generators, Attachable // @@ -1208,6 +1212,8 @@ module jittered_poly(path, dist=1/512) { // cap_h = if given, height above center where the shape will be truncated. // --- // d = diameter of circular portion of bottom. (Use instead of r) +// circum = if true, create a circumscribing teardrop. Default: false +// realign = if true, change whether bottom of teardrop is a point or a flat. Default: false // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `CENTER` // spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). Default: `0` // @@ -1217,9 +1223,9 @@ module jittered_poly(path, dist=1/512) { // teardrop2d(r=30, ang=30, cap_h=40); // Example(2D): Close Crop // teardrop2d(r=30, ang=30, cap_h=20); -module teardrop2d(r, ang=45, cap_h, d, anchor=CENTER, spin=0) +module teardrop2d(r, ang=45, cap_h, d, circum=false, realign=false, anchor=CENTER, spin=0) { - path = teardrop2d(r=r, d=d, ang=ang, cap_h=cap_h); + path = teardrop2d(r=r, d=d, ang=ang, circum=circum, realign=realign, cap_h=cap_h); attachable(anchor,spin, two_d=true, path=path, extent=false) { polygon(path); children(); @@ -1229,20 +1235,54 @@ module teardrop2d(r, ang=45, cap_h, d, anchor=CENTER, spin=0) // _extrapt = true causes the point to be duplicated so a teardrop with no cap // has the same point count as one with a cap. -function teardrop2d(r, ang=45, cap_h, d, anchor=CENTER, spin=0, _extrapt=false) = +function teardrop2d(r, ang=45, cap_h, d, circum=false, realign=false, anchor=CENTER, spin=0, _extrapt=false) = let( r = get_radius(r=r, d=d, dflt=1), - ang2=90-ang, minheight = r*sin(ang), - maxheight = r/cos(ang2) + maxheight = r/sin(ang), //cos(90-ang), + pointycap = is_undef(cap_h) || cap_h>=maxheight ) assert(is_undef(cap_h) || cap_h>=minheight, str("cap_h cannot be less than ",minheight," but it is ",cap_h)) let( - firstpt = is_undef(cap_h) || cap_h>=maxheight ? [[0,maxheight]] - : [[(maxheight-cap_h)*tan(ang), cap_h]], - lastpt = !_extrapt && (is_undef(cap_h) || cap_h>=maxheight) ? [] : [[-firstpt[0].x,firstpt[0].y]], - path = concat(firstpt, arc(angle=[ang, -180-ang], r=r), lastpt) - ) reorient(anchor,spin, two_d=true, path=path, p=path, extent=false); + cap = [ + pointycap? [0,maxheight] : [(maxheight-cap_h)*tan(ang), cap_h], + r*[cos(ang),sin(ang)] + ], + fullcircle = ellipse(r=r, realign=realign, circum=circum,spin=90), + + // Chose the point on the circle that is lower than the cap but also creates a segment bigger than + // seglen/3 so we don't have a teeny tiny segment at the end of the cap + path = !circum ? + let(seglen = norm(fullcircle[0]-fullcircle[1])) + [ + each cap, + for (p=fullcircle) + if ( + p.yseglen/3 + ) p, + xflip(cap[1]), + if (_extrapt || !pointycap) xflip(cap[0]) + ] + : let( + isect = [for(i=[0:1:len(fullcircle)/4]) + let(p = line_intersection(cap, select(fullcircle,[i,i+1]), bounded1=RAY, bounded2=SEGMENT)) + if (p) [i,p] + ], + i = last(isect)[0], + p = last(isect)[1], + ff=echo(isect) + ) + [ + cap[0], + p, + each select(fullcircle,i+1,-i-1-(realign?1:0)), + xflip(p), + if(_extrapt || !pointycap) xflip(cap[0]) + ] + ) + reorient(anchor,spin, two_d=true, path=path, p=path, extent=false); + // Function&Module: egg() diff --git a/shapes3d.scad b/shapes3d.scad index 36f7046..f4a3135 100644 --- a/shapes3d.scad +++ b/shapes3d.scad @@ -2502,6 +2502,7 @@ function torus( // ang = Angle of hat walls from the Z axis. Default: 45 degrees // cap_h = If given, height above center where the shape will be truncated. Default: `undef` (no truncation) // --- +// circum = produce a circumscribing teardrop shape. Default: false // r1 = Radius of circular portion of the front end of the teardrop shape. // r2 = Radius of circular portion of the back end of the teardrop shape. // d = Diameter of circular portion of the teardrop shape. @@ -2512,6 +2513,7 @@ function torus( // chamfer = Specifies size of chamfer as distance along the bottom and top faces. Default: 0 // chamfer1 = Specifies size of chamfer on bottom as distance along bottom face. Default: 0 // chamfer2 = Specifies size of chamfer on top as distance along top face. Default: 0 +// realign = Passes realign option to teardrop2d, which shifts face alignment. Default: false // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `CENTER` // spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). Default: `0` // orient = Vector to rotate top towards, after spin. See [orient](attachments.scad#subsection-orient). Default: `UP` @@ -2541,7 +2543,8 @@ function torus( // teardrop(d1=20, d2=30, h=20, cap_h1=11, cap_h2=16) // show_anchors(std=false); -module teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, l, length, height, chamfer, chamfer1, chamfer2,anchor=CENTER, spin=0, orient=UP) +module teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, l, length, height, circum=false, realign=false, + chamfer, chamfer1, chamfer2,anchor=CENTER, spin=0, orient=UP) { length = one_defined([l, h, length, height],"l,h,length,height"); r1 = get_radius(r=r, r1=r1, d=d, d1=d1); @@ -2550,7 +2553,6 @@ module teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, l, lengt tip_y2 = r2/cos(90-ang); _cap_h1 = min(default(cap_h1, tip_y1), tip_y1); _cap_h2 = min(default(cap_h2, tip_y2), tip_y2); - f= echo(fff=_cap_h1,_cap_h2); capvec = unit([0, _cap_h1-_cap_h2, length]); anchors = [ named_anchor("cap", [0,0,(_cap_h1+_cap_h2)/2], capvec), @@ -2559,14 +2561,14 @@ module teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, l, lengt ]; attachable(anchor,spin,orient, r1=r1, r2=r2, l=length, axis=BACK, anchors=anchors) { - vnf_polyhedron(teardrop(ang=ang,cap_h=cap_h,r1=r1,r2=r2,cap_h1=cap_h1,cap_h2=cap_h2, + vnf_polyhedron(teardrop(ang=ang,cap_h=cap_h,r1=r1,r2=r2,cap_h1=cap_h1,cap_h2=cap_h2,circum=circum,realign=realign, length=length, chamfer1=chamfer1,chamfer2=chamfer2,chamfer=chamfer)); children(); } } -function teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, chamfer, chamfer1, chamfer2, +function teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, chamfer, chamfer1, chamfer2, circum=false, realign=false, l, length, height, anchor=CENTER, spin=0, orient=UP) = let( r1 = get_radius(r=r, r1=r1, d=d, d1=d1, dflt=1), @@ -2577,8 +2579,8 @@ function teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, chamf chamfer1 = first_defined([chamfer1,chamfer,0]), chamfer2 = first_defined([chamfer2,chamfer,0]), sides = segs(max(r1,r2)), - profile1 = teardrop2d(r=r1, ang=ang, cap_h=cap_h1, $fn=sides, _extrapt=true), - profile2 = teardrop2d(r=r2, ang=ang, cap_h=cap_h2, $fn=sides, _extrapt=true), + profile1 = teardrop2d(r=r1, ang=ang, cap_h=cap_h1, $fn=sides, circum=circum, realign=realign,_extrapt=true), + profile2 = teardrop2d(r=r2, ang=ang, cap_h=cap_h2, $fn=sides, circum=circum, realign=realign,_extrapt=true), tip_y1 = r1/cos(90-ang), tip_y2 = r2/cos(90-ang), _cap_h1 = min(default(cap_h1, tip_y1), tip_y1), @@ -2590,10 +2592,9 @@ function teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, chamf assert(is_undef(cap_h1) || cap_h1-chamfer1 > r1*sin(ang), "chamfer1 is too big to work with the specified cap_h1") assert(is_undef(cap_h2) || cap_h2-chamfer2 > r2*sin(ang), "chamfer2 is too big to work with the specified cap_h2"), cprof1 = r1==chamfer1 ? repeat([0,0],len(profile1)) - : teardrop2d(r=r1-chamfer1, ang=ang, cap_h=u_add(cap_h1,-chamfer1), $fn=sides, _extrapt=true), + : teardrop2d(r=r1-chamfer1, ang=ang, cap_h=u_add(cap_h1,-chamfer1), $fn=sides, circum=circum, realign=realign,_extrapt=true), cprof2 = r2==chamfer2 ? repeat([0,0],len(profile2)) - : teardrop2d(r=r2-chamfer2, ang=ang, cap_h=u_add(cap_h2,-chamfer2), $fn=sides, _extrapt=true), - fefda= echo(lens=len(cprof1),len(cprof2)), + : teardrop2d(r=r2-chamfer2, ang=ang, cap_h=u_add(cap_h2,-chamfer2), $fn=sides, circum=circum, realign=realign,_extrapt=true), anchors = [ named_anchor("cap", [0,0,(_cap_h1+_cap_h2)/2], capvec), named_anchor("cap_fwd", [0,-length/2,_cap_h1], unit((capvec+FWD)/2)),