diff --git a/attachments.scad b/attachments.scad index 33e1aac..dbb6dc6 100644 --- a/attachments.scad +++ b/attachments.scad @@ -2774,6 +2774,41 @@ function reorient( function named_anchor(name, pos, orient=UP, spin=0) = [name, pos, orient, spin]; +function _force_rot(T) = + [for(i=[0:3]) + [for(j=[0:3]) j<3 ? T[i][j] : + i==3 ? 1 + : 0]]; + +// Function: transform_anchor() +// Synopsis: Creates an anchor data structure from a transformation matrix +// Topics: Attachments +// See Also: reorient(), attachable() +// Usage: +// a = transform_anchor(name, transform, [flip]); +// Description: +// Creates an anchor data structure from a transformation matrix. For a step-by-step explanation of attachments, +// see the [Attachments Tutorial](Tutorial-Attachments). +// Arguments: +// name = The string name of the anchor. Lowercase. Words separated by single dashes. No spaces. +// transform = A rotation matrix (which may include translation) +// flip = If true, flip the anchor the opposite direction. Default: false + +function transform_anchor(name, transform, flip=false) = + let( + pos = apply(transform,CTR), + rotpart = _force_rot(transform), + dir = flip ? apply(rotpart,DOWN) + : apply(rotpart,UP), + transform = flip? affine3d_rot_by_axis(apply(rotpart,BACK),180)*transform + : transform, + decode=rot_decode(rot(to=UP,from=dir)*_force_rot(transform)), + spin = decode[0]*sign(decode[1].z) + ) + [name, pos,dir,spin]; + + + // Function: attach_geom() // Synopsis: Returns the internal geometry description of an attachable object. // Topics: Attachments @@ -3201,7 +3236,6 @@ function _attach_transform(anchor, spin, orient, geom, p) = assert(is_undef(orient) || is_vector(orient,3), str("Got: ",orient)) let( anchor = default(anchor, CENTER), - spin = default(spin, 0), orient = default(orient, UP), two_d = _attach_geom_2d(geom), @@ -3209,12 +3243,13 @@ function _attach_transform(anchor, spin, orient, geom, p) = let( anch = _find_anchor($attach_to, geom), pos = anch[1] - ) two_d? ( - assert(two_d && is_num(spin)) - affine3d_zrot(spin) * - rot(to=FWD, from=point3d(anch[2])) * - affine3d_translate(point3d(-pos)) - ) : ( + ) + two_d? + assert(is_num(spin)) + affine3d_zrot(spin) + * rot(to=FWD, from=point3d(anch[2])) + * affine3d_translate(point3d(-pos)) + : assert(is_num(spin) || is_vector(spin,3)) let( ang = vector_angle(anch[2], DOWN), @@ -3222,40 +3257,33 @@ function _attach_transform(anchor, spin, orient, geom, p) = ang2 = (anch[2]==UP || anch[2]==DOWN)? 0 : 180-anch[3], axis2 = rot(p=axis,[0,0,ang2]) ) - affine3d_rot_by_axis(axis2,ang) * ( - is_num(spin)? affine3d_zrot(ang2+spin) : ( - affine3d_zrot(spin.z) * - affine3d_yrot(spin.y) * - affine3d_xrot(spin.x) * - affine3d_zrot(ang2) - ) - ) * affine3d_translate(point3d(-pos)) - ) + affine3d_rot_by_axis(axis2,ang) + * (is_num(spin)? affine3d_zrot(ang2+spin) + : affine3d_zrot(spin.z) * affine3d_yrot(spin.y) * affine3d_xrot(spin.x) + * affine3d_zrot(ang2)) + * affine3d_translate(point3d(-pos)) ) : ( let( pos = _find_anchor(anchor, geom)[1] - ) two_d? ( - assert(two_d && is_num(spin)) - affine3d_zrot(spin) * - affine3d_translate(point3d(-pos)) - ) : ( + ) + two_d? + assert(is_num(spin)) + affine3d_zrot(spin) * affine3d_translate(point3d(-pos)) + : assert(is_num(spin) || is_vector(spin,3)) let( axis = vector_axis(UP,orient), ang = vector_angle(UP,orient) ) - affine3d_rot_by_axis(axis,ang) * ( - is_num(spin)? affine3d_zrot(spin) : ( - affine3d_zrot(spin.z) * - affine3d_yrot(spin.y) * - affine3d_xrot(spin.x) - ) - ) * affine3d_translate(point3d(-pos)) - ) + affine3d_rot_by_axis(axis,ang) + * ( is_num(spin)? affine3d_zrot(spin) + : affine3d_zrot(spin.z) * affine3d_yrot(spin.y) * affine3d_xrot(spin.x)) + * affine3d_translate(point3d(-pos)) ) - ) is_undef(p)? m : - is_vnf(p)? [(p==EMPTY_VNF? p : apply(m, p[0])), p[1]] : - apply(m, p); + ) + is_undef(p)? m + : is_vnf(p) && p==EMPTY_VNF? p + : apply(m, p); function _get_cp(geom) = diff --git a/skin.scad b/skin.scad index cb08842..2464251 100644 --- a/skin.scad +++ b/skin.scad @@ -1481,6 +1481,11 @@ module spiral_sweep(poly, h, r, turns=1, taper, r1, r2, d, d1, d2, internal=fals // Anchor Types: // "hull" = Anchors to the virtual convex hull of the shape. // "intersect" = Anchors to the surface of the shape. +// Extra Anchors: +// start = When `closed==false`, the origin point of the shape, on the starting face of the object +// end = When `closed==false`, the origin point of the shape, on the ending face of the object +// start-centroid = When `closed==false`, the centroid of the shape, on the starting face of the object +// end-centroid = When `closed==false`, the centroid of the shape, on the ending face of the object // Example(NoScales): A simple sweep of a square along a sine wave: // path = [for(theta=[-180:5:180]) [theta/10, 10*sin(theta)]]; // sq = square(6,center=true); @@ -1755,29 +1760,60 @@ module spiral_sweep(poly, h, r, turns=1, taper, r1, r2, d, d1, d2, internal=fals // path_sweep(left(.05,square([1.1,1])), curve, closed=true, // method="manual", normal=UP); // } +// Example(Med,NoScales,VPR=[78.1,0,43.2],VPT=[2.18042,-0.485127,1.90371],VPD=74.4017): The "start" and "end" anchors are located at the origin point of the swept shape. +// shape = back_half(right_half(star(n=5,id=5,od=10)),y=-1); +// path = arc(angle=[0,180],d=30); +// path_sweep(shape,path,method="natural"){ +// attach(["start","end"]) anchor_arrow(s=5); +// } +// Example(Med,NoScales,VPR=[78.1,0,43.2],VPT=[2.18042,-0.485127,1.90371],VPD=74.4017): The "start" and "end" anchors are located at the origin point of the swept shape. +// shape = back_half(right_half(star(n=5,id=5,od=10)),y=-1); +// path = arc(angle=[0,180],d=30); +// path_sweep(shape,path,method="natural"){ +// attach(["start-centroid","end-centroid"]) anchor_arrow(s=5); +// } +// Example(Med,NoScales,VPR=[78.1,0,43.2],VPT=[2.18042,-0.485127,1.90371],VPD=74.4017): Note that the "start" anchors are backwards compared to the direction of the sweep, so you have to attach the TOP to align the shape with its ends. +// shape = back_half(right_half(star(n=5,id=5,od=10)),y=-1); +// path = arc(angle=[0,180],d=30); +// path_sweep(shape,path,method="natural") +// recolor("red"){ +// attach("start",TOP) stroke([path3d(shape[0])],width=.5); +// attach("end") stroke([path3d(last(shape))],width=.5); +// } + module path_sweep(shape, path, method="incremental", normal, closed, twist=0, twist_by_length=true, scale=1, scale_by_length=true, symmetry=1, last_normal, tangent, uniform=true, relaxed=false, caps, style="min_edge", convexity=10, anchor="origin",cp="centroid",spin=0, orient=UP, atype="hull",profiles=false,width=1) { - dummy = assert(is_region(shape) || is_path(shape,2), "shape must be a 2D path or region"); - vnf = path_sweep(shape, path, method, normal, closed, twist, twist_by_length, scale, scale_by_length, - symmetry, last_normal, tangent, uniform, relaxed, caps, style); - + dummy = assert(is_region(shape) || is_path(shape,2), "shape must be a 2D path or region") + assert(in_list(atype, _ANCHOR_TYPES), "Anchor type must be \"hull\" or \"intersect\""); + transforms = path_sweep(shape, path, method, normal, closed, twist, twist_by_length, scale, scale_by_length, + symmetry, last_normal, tangent, uniform, relaxed, caps, style, transforms=true); + vnf = sweep(is_path(shape)?clockwise_polygon(shape):shape, transforms, closed=false, caps=caps,style=style); + shapecent = point3d(centroid(shape)); + $transforms = transforms; + anchors = closed ? [] + : + [ + transform_anchor("start", transforms[0], invert=true), + transform_anchor("end", last(transforms)), + transform_anchor("start-centroid", transforms[0]*move(shapecent), invert=true), + transform_anchor("end-centroid", last(transforms)*move(shapecent)) + ]; if (profiles){ - assert(in_list(atype, _ANCHOR_TYPES), "Anchor type must be \"hull\" or \"intersect\""); - tran = path_sweep(shape, path, method, normal, closed, twist, twist_by_length, scale, scale_by_length, - symmetry, last_normal, tangent, uniform, relaxed,transforms=true); rshape = is_path(shape) ? [path3d(shape)] : [for(s=shape) path3d(s)]; - attachable(anchor,spin,orient, vnf=vnf, extent=atype=="hull", cp=cp) { - for(T=tran) stroke([for(part=rshape)apply(T,part)],width=width); + attachable(anchor,spin,orient, vnf=vnf, extent=atype=="hull", cp=cp, anchors=anchors) { + for(T=transforms) stroke([for(part=rshape)apply(T,part)],width=width); children(); } } else - vnf_polyhedron(vnf,convexity=convexity,anchor=anchor, spin=spin, orient=orient, atype=atype, cp=cp) + attachable(anchor,spin,orient,vnf=vnf,extent=atype=="hull", cp=cp,anchors=anchors){ + vnf_polyhedron(vnf,convexity=convexity); children(); + } }