From 58fe83448935f9c5b50ddb95e0ebad6d93c9b3f2 Mon Sep 17 00:00:00 2001 From: djerun Date: Fri, 27 Jun 2025 09:00:23 +0200 Subject: [PATCH] [WIP] add polyhedron-based catears --- catear_headband.scad | 179 ++++++++++++++++++++++-------------------- pressfit_catears.scad | 18 ++++- primitives.scad | 86 +++++++++++++++++--- 3 files changed, 187 insertions(+), 96 deletions(-) diff --git a/catear_headband.scad b/catear_headband.scad index 2606ce1..7456ba3 100644 --- a/catear_headband.scad +++ b/catear_headband.scad @@ -25,7 +25,12 @@ module catear_v3(height, thickness, fractal=0, side_len=30, bend_factor=0.15, st C = [-S*bf, S*sf*mn, 0] * R; D = [-s , 0, 0]; - if (debug) translate([0, 0, height]) rotate(90) bezier_curve_debug([A, B, C, D]); + curve_vertices = bezier_curve_vertices([A, B, C, D], $fn); + if (debug) { + translate([0, 0, height]) rotate(90) bezier_curve_debug([A, B, C, D]); + echo("curve_vertices: ", curve_vertices); + } + rotate(90) render_curve(curve_vertices, width=thickness, height=height, chamfer=chamfer); } /** @@ -125,96 +130,102 @@ module catear_v1(height, thickness, fractal=0, side_len=30, bend_factor=0.15, st } } -module catear_headband(debug=DEBUG, size=SIZE, height=HEIGHT, thickness=THICKNESS, part=PART, stretch_len=STRETCH_LEN, tip_len=TIP_LEN, tip_bend=TIP_BEND, ear_scale=1.5, ear_bend_factor=0.15, ear_stretch_factor=1.2, ear_angle=42, chamfer=CHAMFER, chamfer_shape=CHAMFER_SHAPE, with_rake=true, details=true, ear_skew=2.0) { +module catear_headband(debug=DEBUG, size=SIZE, height=HEIGHT, thickness=THICKNESS, part=PART, stretch_len=STRETCH_LEN, tip_len=TIP_LEN, tip_bend=TIP_BEND, ear_scale=1.5, ear_bend_factor=0.15, ear_stretch_factor=1.2, ear_angle=42, chamfer=CHAMFER, chamfer_shape=CHAMFER_SHAPE, with_rake=true, details=true, ear_skew=2.0, ear_version=3) { $a=size/2*ear_scale; $delta=2*(acos($a/(size*2))-90); ear_offset=size*sin(90-$delta/2); union() { - rotate( ear_angle, [0, 0, 1]) { - translate([-ear_offset, 0, 0]) catear_v3( - debug=debug, - height=height, - thickness=thickness, - side_len=size/2*ear_scale, - bend_factor=ear_bend_factor, - stretch_factor=ear_stretch_factor, - chamfer=chamfer, - chamfer_shape=chamfer_shape, - details=details, - skew=ear_skew - ); + if (ear_version == 3 ) { + rotate( ear_angle, [0, 0, 1]) { + translate([-ear_offset, 0, 0]) catear_v3( + debug=debug, + height=height, + thickness=thickness, + side_len=size/2*ear_scale, + bend_factor=ear_bend_factor, + stretch_factor=ear_stretch_factor, + chamfer=chamfer, + chamfer_shape=chamfer_shape, + details=details, + skew=ear_skew + ); + } + rotate(-ear_angle, [0, 0, 1]) { + translate([-ear_offset, 0, 0]) catear_v3( + debug=false, + height=height, + thickness=thickness, + side_len=size/2*ear_scale, + bend_factor=ear_bend_factor, + stretch_factor=ear_stretch_factor, + chamfer=chamfer, + chamfer_shape=chamfer_shape, + details=details, + skew=-ear_skew + ); + } } - rotate( ear_angle, [0, 0, 1]) { - translate([-ear_offset, 0, -2*height]) catear_v2( - debug=debug, - height=height, - thickness=thickness, - side_len=size/2*ear_scale, - bend_factor=ear_bend_factor, - stretch_factor=ear_stretch_factor, - chamfer=chamfer, - chamfer_shape=chamfer_shape, - details=details, - skew=ear_skew - ); + if (ear_version == 2 ) { + rotate( ear_angle, [0, 0, 1]) { + translate([-ear_offset, 0, 0]) catear_v2( + debug=debug, + height=height, + thickness=thickness, + side_len=size/2*ear_scale, + bend_factor=ear_bend_factor, + stretch_factor=ear_stretch_factor, + chamfer=chamfer, + chamfer_shape=chamfer_shape, + details=details, + skew=ear_skew + ); + } + rotate(-ear_angle, [0, 0, 1]) { + translate([-ear_offset, 0, 0]) catear_v2( + debug=false, + height=height, + thickness=thickness, + side_len=size/2*ear_scale, + bend_factor=ear_bend_factor, + stretch_factor=ear_stretch_factor, + chamfer=chamfer, + chamfer_shape=chamfer_shape, + details=details, + skew=-ear_skew + ); + } } - rotate( ear_angle, [0, 0, 1]) { - translate([-ear_offset, 0, -height]) catear_v1( - debug=debug, - height=height, - thickness=thickness, - side_len=size/2*ear_scale, - bend_factor=ear_bend_factor, - stretch_factor=ear_stretch_factor, - chamfer=chamfer, - chamfer_shape=chamfer_shape, - details=details, - skew=ear_skew - ); - } - rotate(-ear_angle, [0, 0, 1]) { - translate([-ear_offset, 0, 0]) catear_v3( - debug=false, - height=height, - thickness=thickness, - side_len=size/2*ear_scale, - bend_factor=ear_bend_factor, - stretch_factor=ear_stretch_factor, - chamfer=chamfer, - chamfer_shape=chamfer_shape, - details=details, - skew=-ear_skew - ); - } - rotate(-ear_angle, [0, 0, 1]) { - translate([-ear_offset, 0, -2*height]) catear_v2( - debug=false, - height=height, - thickness=thickness, - side_len=size/2*ear_scale, - bend_factor=ear_bend_factor, - stretch_factor=ear_stretch_factor, - chamfer=chamfer, - chamfer_shape=chamfer_shape, - details=details, - skew=-ear_skew - ); - } - rotate(-ear_angle, [0, 0, 1]) { - translate([-ear_offset, 0, -height]) catear_v1( - debug=false, - height=height, - thickness=thickness, - side_len=size/2*ear_scale, - bend_factor=ear_bend_factor, - stretch_factor=ear_stretch_factor, - chamfer=chamfer, - chamfer_shape=chamfer_shape, - details=details, - skew=-ear_skew - ); + if (ear_version == 1 ) { + rotate( ear_angle, [0, 0, 1]) { + translate([-ear_offset, 0, 0]) catear_v1( + debug=debug, + height=height, + thickness=thickness, + side_len=size/2*ear_scale, + bend_factor=ear_bend_factor, + stretch_factor=ear_stretch_factor, + chamfer=chamfer, + chamfer_shape=chamfer_shape, + details=details, + skew=ear_skew + ); + } + rotate(-ear_angle, [0, 0, 1]) { + translate([-ear_offset, 0, 0]) catear_v1( + debug=false, + height=height, + thickness=thickness, + side_len=size/2*ear_scale, + bend_factor=ear_bend_factor, + stretch_factor=ear_stretch_factor, + chamfer=chamfer, + chamfer_shape=chamfer_shape, + details=details, + skew=-ear_skew + ); + } } headband( size=size, @@ -230,4 +241,4 @@ module catear_headband(debug=DEBUG, size=SIZE, height=HEIGHT, thickness=THICKNES }; } -rotate(-90) catear_headband(ear_bend_factor=0.15, ear_skew=2, debug=true); +rotate(-90) catear_headband(ear_bend_factor=0.15, ear_skew=2, ear_version=3); diff --git a/pressfit_catears.scad b/pressfit_catears.scad index 05e2a41..58f255b 100644 --- a/pressfit_catears.scad +++ b/pressfit_catears.scad @@ -50,9 +50,21 @@ g = function (p) [scalc(xremap, p.x, -S/2, S/2), scalc(yremap, p.y, 0, S/2)*e, p rotate([0, 90, 0]) color("yellow") arc(0.5, r, THICKNESS, HEIGHT, outer_remap=f, inner_remap=g); -color("red") catear_v2(HEIGHT, THICKNESS, side_len=SIZE/2*EAR_SCALE, stretch_factor=EAR_STRETCH_FACTOR); +color("red") catear_v2( + height=HEIGHT, + thickness=THICKNESS, + side_len=SIZE/2*EAR_SCALE, + stretch_factor=EAR_STRETCH_FACTOR +); // a = b + c // x * a = y * b + c -// y / x = a /(b + c) -// y = x * a /(b + c) +// y * b = x * a - c +// y =(x * a - c)/ b + +// 100 = 95 + 5 +// x * 100 = y * 95 + 5 +// 5 * 100 = y * 95 + 5 +// 500 = y * 95 + 5 +// 495 = y * 95 +// y = 495 / 95 diff --git a/primitives.scad b/primitives.scad index b73deca..72d37ca 100644 --- a/primitives.scad +++ b/primitives.scad @@ -33,23 +33,91 @@ module bezier_curve_debug(control_points, $fn=$fn) { color("green") translate(bezier_spline(control_points, 0.5)) sphere(d=1, $fn=24); } +// c^2=a^2+b^2 // a == b +// c^2=2a^2 // /2 +// c^2/2=a^2 // sqrt +// sqrt(c^2/2)=a +chamfer_offset = function (c) sqrt((c*c)/2); +rendered_curve_segment_vertices = function (p, v, n, width, height, chamfer) + let (d=normalize(n-p)) let (up=[0, 0, 1]) let (right=normalize(cross(d, up))) [ + //p, v, n, width, height, chamfer_offset(chamfer), d, up, right, + v+up*(height/2)+right*(-width/2+chamfer_offset(chamfer)), + v+up*(height/2)+right*(width/2-chamfer_offset(chamfer)), + v+up*(height/2-chamfer_offset(chamfer))+right*(width/2), + v+up*(-height/2+chamfer_offset(chamfer))+right*(width/2), + v+up*(-height/2)+right*(width/2-chamfer_offset(chamfer)), + v+up*(-height/2)+right*(-width/2+chamfer_offset(chamfer)), + v+up*(-height/2+chamfer_offset(chamfer))+right*(-width/2), + v+up*(height/2-chamfer_offset(chamfer))+right*(-width/2) +]; -rendered_curve_segment_vertices = function (p, v, n, width, height, chamfer) []; +module render_curve(curve_vertices, width, height, chamfer, debug=false) { + /* + * vertex generation order: + * - we generate vertices segment by segment + * - one segement for every curve vertex provided + * - each segment has eight vertices that form the outer ring + * - the corners are chamfered so the vertices are pairs at the corners + * - we start with the top segment and move clockwise + * - top-down axis is determined globally by z-axis unless direction at start vertex is z + * - if direction at start vertes is z, top-down is y-adis instead + * - the left vertex of the top edge is 0, the other is 1 + * - left-right axis is determined by normal between travel direction and up-down axis + * - the last vertex is part of the same corner as 0 but part of the left edge + * - segment edge n has vertices `n` and `(n+1)%8` + * - segment joining edge n has vertices local index `n` of both segments + * - global `i` index of local index `n` for segment `m` is `i=8*m+n` + * - so we have `count=length(curve_vertices)` segments and `count*8` vertices + * - we are not generating a thorus so the faces for our polyhedron are: + * - two eight sided end cap faces + * - `(count-1)*8` four sided mantle faces + * - direction at vertex is the vector from the previonus to the next vertex + * - for the first an last vertex the only neighbor is mirrored around the vertex + * - the start end cap is face `0` + * - the face mantle face n has vertices `[n, +(n+1)%8, n+8, n+8+(n+1)%8]` + * - the stop end cap is face `count*8` + */ -module render_curve(curve_vertices, width, height, chamfer) { - start = let(v=curve_vertices[0], n=curve_vertices[1]) let(p=v-n) + start = let(v=curve_vertices[0], n=curve_vertices[1]) let(p=v+(v-n)) rendered_curve_segment_vertices(p, v, n, width, height, chamfer); + echo("len(curve_vertices): ", len(curve_vertices)); middle = [ for (i=[1:len(curve_vertices)-2]) let( - p = curve_vertives[i-1], + p = curve_vertices[i-1], v = curve_vertices[i], - n = curve_vertives[i+1] - ) rendered_curve_segment_vertices(p, v, n, width, height, chamfer) + n = curve_vertices[i+1] + ) each rendered_curve_segment_vertices(p, v, n, width, height, chamfer) ]; - end = let(i=len(curve_vertices)) let(v=curve_vertices[i], p=curve_vertices[i-1]) let(n=v-p) - rendered_curve_segment_vertices(p, v, n, width, height, chamfer); + echo("len(middle): ", len(middle)); + stop = let(i=len(curve_vertices)) + let(v=curve_vertices[i-1], p=curve_vertices[i-2]) let(n=v+(v-p)) + rendered_curve_segment_vertices(p, v, n, width, height, chamfer); - // TODO + if (debug) { + echo(start); + color("#ff00ff") for (v = start) translate(v+[0, 0, height]) sphere(d=.25, $fn=16); + echo(middle); + color("white") for (v = middle) translate(v+[0, 0, height]) sphere(d=.25, $fn=16); + echo(stop); + color("cyan") for (v = stop) translate(v+[0, 0, height]) sphere(d=.25, $fn=16); + } + + render_vertices = concat(start, middle, stop); + echo("len(render_vertices)", len(render_vertices)); + echo(render_vertices); + + start_cap = [ for (i=[0:1:7]) i]; + echo(start_cap); + mantle = let (M=len(curve_vertices)-1) [ for (m=[0:M-1],n=[0:7]) let (i=m*8+n) + [i, i+8, n==7 ? i+1 : i+8+1, n==7 ? i-7 : i+1] + ]; + echo(mantle); + end_cap = let (m=len(curve_vertices)-1) [ for (i=[m*8+7:-1:m*8]) i ]; + echo(end_cap); + + faces = concat([start_cap], mantle, [end_cap]); + + translate([0, 0, debug ? height : 0]) polyhedron(points=render_vertices, faces=faces); } arc_vertex = function (a, r, t, translate=[0,0,0], remap=id) remap([