diff --git a/attachments.scad b/attachments.scad index dbb6dc6..34e45e5 100644 --- a/attachments.scad +++ b/attachments.scad @@ -2763,16 +2763,40 @@ function reorient( // See Also: reorient(), attachable() // Usage: // a = named_anchor(name, pos, [orient], [spin]); +// a = named_anchor(name, [pos], rot=, [flip=]); // Description: -// Creates an anchor data structure. For a step-by-step explanation of attachments, +// Creates an anchor data structure. You can specify the position, orient direction and spin directly. +// Alternatively for the 3D case you can give a 4x4 rotation matrix which can specify the orient and spin, and optionally +// the position, using a translation component of the matrix. If you specify `pos` along with `rot` then the position you +// give overrides any translation included in `rot`. 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. // pos = The [X,Y,Z] position of the anchor. // orient = A vector pointing in the direction parts should project from the anchor position. Default: UP // spin = If needed, the angle to rotate the part around the direction vector. Default: 0 -function named_anchor(name, pos, orient=UP, spin=0) = [name, pos, orient, spin]; - +// --- +// rot = A 4x4 rotations matrix, which may include a translation +// flip = If true, flip the anchor the opposite direction. Default: false +function named_anchor(name, pos, orient, spin, rot, flip) = + assert(num_defined([orient,spin])==0 || num_defined([rot,flip])==0, "Cannot mix orient or spin with rot or flip") + assert(num_defined([pos,rot])>0, "Must give pos or rot") + is_undef(rot) ? [name, pos, default(orient,UP), default(spin,0)] + : + let( + flip = default(flip,false), + pos = default(pos,apply(rot,CTR)), + rotpart = _force_rot(rot), + dummy = assert(approx(det4(rotpart),1), "Input rotation is not a rotation matrix"), + dir = flip ? apply(rotpart,DOWN) + : apply(rotpart,UP), + rot = flip? affine3d_rot_by_axis(apply(rotpart,BACK),180)*rot + : rot, + decode=rot_decode(rot(to=UP,from=dir)*_force_rot(rot)), + spin = decode[0]*sign(decode[1].z) + ) + [name, pos, dir, spin]; + function _force_rot(T) = [for(i=[0:3]) @@ -2780,35 +2804,6 @@ function _force_rot(T) = 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 diff --git a/skin.scad b/skin.scad index 0a9afc3..70ce9c4 100644 --- a/skin.scad +++ b/skin.scad @@ -1479,7 +1479,8 @@ module spiral_sweep(poly, h, r, turns=1, taper, r1, r2, d, d1, d2, internal=fals // atype = Select "hull" or "intersect" anchor types. Default: "hull" // cp = Centerpoint for determining "intersect" anchors or centering the shape. Determintes the base of the anchor vector. Can be "centroid", "mean", "box" or a 3D point. Default: "centroid" // Side Effects: -// `$transforms` is set to the array of transformation matrices that define the swept object. +// `$transforms` is set to the array of transformation matrices that define the swept object. +// `$scales` is set to the array of scales that were applied at each point to create the swept object. // Anchor Types: // "hull" = Anchors to the virtual convex hull of the shape. // "intersect" = Anchors to the surface of the shape. @@ -1775,33 +1776,38 @@ module spiral_sweep(poly, h, r, turns=1, taper, r1, r2, d, d1, d2, internal=fals // 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); +// shape = back_half(right_half(star(n=5,id=5,od=10)),y=-1)[0]; // path = arc(angle=[0,180],d=30); -// path_sweep(shape,path,method="natural") +// path_sweep(shape,path,method="natural",scale=[1,1.5]) // recolor("red"){ -// attach("start",TOP) stroke([path3d(shape[0])],width=.5); -// attach("end") stroke([path3d(last(shape))],width=.5); +// attach("start",TOP) stroke([path3d(shape)],width=.5); +// attach("end") stroke([path3d(yscale(1.5,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") 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); + trans_scale = 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,_return_scales=true); + transforms = trans_scale[0]; + scales = trans_scale[1]; + firstscale = [1/scales[0].x, 1/scales[0].y]; + lastscale = [1/last(scales).x, 1/last(scales).y]; + echo(scales=firstscale,lastscale); vnf = sweep(is_path(shape)?clockwise_polygon(shape):shape, transforms, closed=false, caps=caps,style=style); shapecent = point3d(centroid(shape)); $transforms = transforms; + $scales = scales; anchors = closed ? [] : [ - transform_anchor("start", transforms[0], flip=true), - transform_anchor("end", last(transforms)), - transform_anchor("start-centroid", transforms[0]*move(shapecent), flip=true), - transform_anchor("end-centroid", last(transforms)*move(shapecent)) + named_anchor("start", rot=transforms[0]*scale(firstscale), flip=true), + named_anchor("end", rot=last(transforms)*scale(lastscale)), + named_anchor("start-centroid", rot=transforms[0]*move(shapecent)*scale(firstscale), flip=true), + named_anchor("end-centroid", rot=last(transforms)*move(shapecent)*scale(lastscale)) ]; if (profiles){ rshape = is_path(shape) ? [path3d(shape)] @@ -1821,11 +1827,11 @@ module path_sweep(shape, path, method="incremental", normal, closed, twist=0, tw function 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", transforms=false, - anchor="origin",cp="centroid",spin=0, orient=UP, atype="hull") = + anchor="origin",cp="centroid",spin=0, orient=UP, atype="hull",_return_scales=false) = is_1region(path) ? path_sweep(shape=shape,path=path[0], method=method, normal=normal, closed=default(closed,true), twist=twist, scale=scale, scale_by_length=scale_by_length, twist_by_length=twist_by_length, symmetry=symmetry, last_normal=last_normal, tangent=tangent, uniform=uniform, relaxed=relaxed, caps=caps, style=style, transforms=transforms, - anchor=anchor, cp=cp, spin=spin, orient=orient, atype=atype) : + anchor=anchor, cp=cp, spin=spin, orient=orient, atype=atype, _return_scales=_return_scales) : let(closed=default(closed,false)) assert(in_list(atype, _ANCHOR_TYPES), "Anchor type must be \"hull\" or \"intersect\"") assert(!closed || twist % (360/symmetry)==0, str("For a closed sweep, twist must be a multiple of 360/symmetry = ",360/symmetry)) @@ -1977,7 +1983,9 @@ function path_sweep(shape, path, method="incremental", normal, closed, twist=0, apply(transform_list[L], rshape)), dummy = ends_match ? 0 : echo("WARNING: ***** The points do not match when closing the model in path_sweep() *****") ) - transforms ? transform_list + transforms && _return_scales + ? [transform_list,scale] +: transforms ? transform_lislt : sweep(is_path(shape)?clockwise_polygon(shape):shape, transform_list, closed=false, caps=fullcaps,style=style, anchor=anchor,cp=cp,spin=spin,orient=orient,atype=atype);