Hid textured_*() functions/modules. Integrated textures into cyl(), linear_sweep(), and rotate_sweep()

shapes3d.scad

@@ -52,6 +52,7 @@ use <builtins.scad>
 // Example: Called as Function
 //   vnf = cube([20,40,50]);
 //   vnf_polyhedron(vnf);
+
 module cube(size=1, center, anchor, spin=0, orient=UP)
 {
     anchor = get_anchor(anchor, center, -[1,1,1], -[1,1,1]);
@@ -177,6 +178,7 @@ function cube(size=1, center, anchor, spin=0, orient=UP) =
 //   cuboid([4,2,1], rounding=2, edges=[FWD+RIGHT,BACK+LEFT]);
 // Example: Standard Connectors
 //   cuboid(40) show_anchors();
+
 module cuboid(
     size=[1,1,1],
     p1, p2,
@@ -633,6 +635,7 @@ function cuboid(
 // Example(Spin,VPD=160,VPT=[0,0,10]): Standard Connectors
 //   prismoid(size1=[50,30], size2=[20,20], h=20, shift=[15,5])
 //       show_anchors();
+
 module prismoid(
     size1, size2, h, shift=[0,0],
     rounding=0, rounding1, rounding2,
@@ -775,6 +778,7 @@ function prismoid(
 //   octahedron(size=40);
 // Example: Anchors
 //   octahedron(size=40) show_anchors();
+
 module octahedron(size=1, anchor=CENTER, spin=0, orient=UP) {
     vnf = octahedron(size=size);
     attachable(anchor,spin,orient, vnf=vnf, extent=true) {
@@ -900,6 +904,7 @@ function octahedron(size=1, anchor=CENTER, spin=0, orient=UP) =
 //       rounding1=[5,0,10,0], irounding1=[3,0,8,0],
 //       rounding2=[0,5,0,10], irounding2=[0,3,0,8]
 //   );
+
 module rect_tube(
     h, size, isize, center, shift=[0,0],
     wall, size1, size2, isize1, isize2,
@@ -1014,6 +1019,7 @@ function rect_tube(
 //   wedge([20, 40, 15]);
 // Example: Standard Connectors
 //   wedge([20, 40, 15]) show_anchors();
+
 module wedge(size=[1, 1, 1], center, anchor, spin=0, orient=UP)
 {
     size = scalar_vec3(size);
@@ -1095,6 +1101,7 @@ function wedge(size=[1,1,1], center, anchor, spin=0, orient=UP) =
 //       cylinder(h=30, d=25) show_anchors();
 //       cylinder(h=30, d1=25, d2=10) show_anchors();
 //   }
+
 module cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
 {
     anchor = get_anchor(anchor, center, BOTTOM, BOTTOM);
@@ -1128,13 +1135,7 @@ function cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
 
 
 
-// Module: cyl()
+// Function&Module: cyl()
-//
-// Description:
-//   Creates cylinders in various anchorings and orientations, with optional rounding and chamfers.
-//   You can use `h` and `l` interchangably, and all variants allow specifying size by either `r`|`d`,
-//   or `r1`|`d1` and `r2`|`d2`.  Note: the chamfers and rounding cannot be cumulatively longer than
-//   the cylinder's length.
 //
 // Usage: Normal Cylinders
 //   cyl(l|h, r, [center], [circum=], [realign=]) [ATTACHMENTS];
@@ -1154,6 +1155,14 @@ function cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
 //   cyl(l|h, r|d, rounding2=, ...);
 //   cyl(l|h, r|d, rounding1=, rounding2=, ...);
 //
+// Topics: Cylinders, Textures, Rounding, Chamfers
+//
+// Description:
+//   Creates cylinders in various anchorings and orientations, with optional rounding and chamfers.
+//   You can use `h` and `l` interchangably, and all variants allow specifying size by either `r`|`d`,
+//   or `r1`|`d1` and `r2`|`d2`.  Note: the chamfers and rounding cannot be cumulatively longer than
+//   the cylinder's length.
+//
 // Arguments:
 //   l / h = Length of cylinder along oriented axis.  Default: 1
 //   r = Radius of cylinder.  Default: 1
@@ -1165,6 +1174,7 @@ function cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
 //   d1 = Diameter of the negative (X-, Y-, Z-) end of cylinder.
 //   d2 = Diameter of the positive (X+, Y+, Z+) end of cylinder.
 //   circum = If true, cylinder should circumscribe the circle of the given size.  Otherwise inscribes.  Default: `false`
+//   shift = [X,Y] amount to shift the center of the top end with respect to the center of the bottom end.
 //   chamfer = The size of the chamfers on the ends of the cylinder.  Default: none.
 //   chamfer1 = The size of the chamfer on the bottom end of the cylinder.  Default: none.
 //   chamfer2 = The size of the chamfer on the top end of the cylinder.  Default: none.
@@ -1176,10 +1186,20 @@ function cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
 //   rounding1 = The radius of the rounding on the bottom end of the cylinder.
 //   rounding2 = The radius of the rounding on the top end of the cylinder.
 //   realign = If true, rotate the cylinder by half the angle of one face.
+//   texture = A texture name string, or a rectangular array of scalar height values (0.0 to 1.0), or a VNF tile that defines the texture to apply to vertical surfaces.  See {{texture()}} for what named textures are supported.
+//   tex_size = An optional 2D target size for the textures.  Actual texture sizes will be scaled somewhat to evenly fit the available surface. Default: `[5,5]`
+//   tex_counts = If given instead of tex_size, gives the tile repetition counts for textures over the surface length and height.
+//   tex_inset = If numeric, lowers the texture into the surface by that amount, before the tex_scale multiplier is applied.  If `true`, insets by exactly `1`.  Default: `false`
+//   tex_rot = If true, rotates the texture 90º.
+//   tex_scale = Scaling multiplier for the texture depth.
+//   tex_samples = Minimum number of "bend points" to have in VNF texture tiles.  Default: 8
+//   tex_style = {{vnf_vertex_array()}} style used to triangulate heightfield textures.  Default: "min_edge"
 //   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`
 //
+// See Also: texture(), rotate_sweep()
+//
 // Example: By Radius
 //   xdistribute(30) {
 //       cyl(l=40, r=10);
@@ -1230,6 +1250,156 @@ function cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
 //       cyl(l=30, d1=25, d2=10) show_anchors();
 //   }
 //
+// Example: Texturing with heightfield diamonds
+//   cyl(h=40, r=20, texture="diamonds", tex_size=[5,5]);
+//
+// Example: Texturing with heightfield pyramids
+//   cyl(h=40, r1=20, r2=15,
+//       texture="pyramids", tex_size=[5,5],
+//       tex_style="convex");
+//
+// Example: Texturing with heightfield truncated pyramids
+//   cyl(h=40, r1=20, r2=15, chamfer=5,
+//       texture="trunc_pyramids",
+//       tex_size=[5,5], tex_style="convex");
+//
+// Example: Texturing with VNF tile "vnf_dots"
+//   cyl(h=40, r1=20, r2=15, rounding=9,
+//       texture="vnf_dots", tex_size=[5,5],
+//       samples=6);
+//
+// Example: Texturing with VNF tile "vnf_bricks"
+//   cyl(h=50, r1=25, r2=20, shift=[0,10], rounding1=-10,
+//       texture="vnf_bricks", tex_size=[10,10],
+//       tex_scale=0.5, tex_style="concave");
+//
+// Example: No Texture Taper
+//   cyl(d1=25, d2=20, h=30, rounding=5,
+//       texture="trunc_ribs", tex_size=[5,1]);
+//
+// Example: Taper Texure at Extreme Ends
+//   cyl(d1=25, d2=20, h=30, rounding=5,
+//       texture="trunc_ribs", taper=0,
+//       tex_size=[5,1]);
+//
+// Example: Taper Texture over First and Last 10%
+//   cyl(d1=25, d2=20, h=30, rounding=5,
+//       texture="trunc_ribs", taper=10,
+//       tex_size=[5,1]);
+
+function cyl(
+    h, r, center,
+    l, r1, r2,
+    d, d1, d2,
+    length, height,
+    chamfer, chamfer1, chamfer2,
+    chamfang, chamfang1, chamfang2,
+    rounding, rounding1, rounding2,
+    circum=false, realign=false,
+    from_end=false, shift=[0,0],
+    texture, tex_size=[5,5], tex_counts,
+    tex_inset=false, tex_rot=false,
+    tex_scale=1, tex_samples,
+    tex_taper, tex_style="min_edge",
+    anchor, spin=0, orient=UP
+) =
+    let(
+        l = first_defined([l, h, length, height, 1]),
+        _r1 = get_radius(r1=r1, r=r, d1=d1, d=d, dflt=1),
+        _r2 = get_radius(r1=r2, r=r, d1=d2, d=d, dflt=1),
+        sides = segs(max(_r1,_r2)),
+        sc = circum? 1/cos(180/sides) : 1,
+        r1 = _r1 * sc,
+        r2 = _r2 * sc,
+        phi = atan2(l, r2-r1),
+        anchor = get_anchor(anchor,center,BOT,CENTER)
+    )
+    assert(is_finite(l), "l/h/length/height must be a finite number.")
+    assert(is_finite(r1), "r/r1/d/d1 must be a finite number.")
+    assert(is_finite(r2), "r2 or d2 must be a finite number.")
+    assert(is_vector(shift,2), "shift must be a 2D vector.")
+    let(
+        vnf = texture != undef? _textured_cylinder(
+                l=l, r1=r1, r2=r2,
+                texture=texture, tex_size=tex_size,
+                counts=tex_counts, tex_scale=tex_scale,
+                inset=tex_inset, rot=tex_rot,
+                style=tex_style, taper=tex_taper,
+                chamfer=chamfer,
+                chamfer1=chamfer1,
+                chamfer2=chamfer2,
+                rounding=rounding,
+                rounding1=rounding1,
+                rounding2=rounding2,
+                samples=tex_samples
+            ) :
+            !any_defined([chamfer, chamfer1, chamfer2, rounding, rounding1, rounding2])?
+                cylinder(h=l, r1=r1, r2=r2, center=true, $fn=sides) :
+            let(
+                vang = atan2(l, r1-r2)/2,
+                chang  = default(chamfang, 45),
+                chang1 = 90-first_defined([chamfang1, chamfang, vang]),
+                chang2 = 90-first_defined([chamfang2, chamfang, 90-vang]),
+                checks1 =
+                    assert(is_finite(chang) && chang>0 && chang<90, "chamfang must be a number between 0 and 90 (exclusive) if given.")
+                    assert(is_finite(chang1) && chang1>0 && chang1<90, "chamfang1 must be a number between 0 and 90 (exclusive) if given.")
+                    assert(is_finite(chang2) && chang2>0 && chang2<90, "chamfang2 must be a number between 0 and 90 (exclusive) if given.")
+                    undef,
+                chamf = default(chamfer, 0) * (from_end? 1 : tan(chang1)),
+                chamf1 = first_defined([chamfer1, chamfer, 0]) * (from_end? 1 : tan(chang1)),
+                chamf2 = first_defined([chamfer2, chamfer, 0]) * (from_end? 1 : tan(chang2)),
+                round  = default(rounding, 0),
+                round1 = first_defined([rounding1, rounding, 0]),
+                round2 = first_defined([rounding2, rounding, 0]),
+                dy1 = abs(first_defined([chamf1, round1, 0])),
+                dy2 = abs(first_defined([chamf2, round2, 0])),
+                checks2 =
+                    assert(is_finite(chamf), "chamfer must be a finite number if given.")
+                    assert(is_finite(chamf1), "chamfer1 must be a finite number if given.")
+                    assert(is_finite(chamf2), "chamfer2 must be a finite number if given.")
+                    assert(is_finite(round), "rounding must be a finite number if given.")
+                    assert(is_finite(round1), "rounding1 must be a finite number if given.")
+                    assert(is_finite(round2), "rounding2 must be a finite number if given.")
+                    assert(chamf <= r1,  "chamfer is larger than the r1 radius of the cylinder.")
+                    assert(chamf <= r2,  "chamfer is larger than the r2 radius of the cylinder.")
+                    assert(chamf1 <= r1, "chamfer1 is larger than the r1 radius of the cylinder.")
+                    assert(chamf2 <= r2, "chamfer2 is larger than the r2 radius of the cylinder.")
+                    assert(round <= r1,  "rounding is larger than the r1 radius of the cylinder.")
+                    assert(round <= r2,  "rounding is larger than the r2 radius of the cylinder.")
+                    assert(round1 <= r1, "rounding1 is larger than the r1 radius of the cylinder.")
+                    assert(round2 <= r2, "rounding2 is larger than the r1 radius of the cylinder.")
+                    assert(dy1+dy2 <= l, "Sum of fillets and chamfer sizes must be less than the length of the cylinder.")
+                    undef,
+                path = [
+                    [0,-l/2],
+                    if (is_finite(chamf1) && !approx(chamf1,0))
+                        let(
+                            p1 = [r1-chamf1/tan(chang1),-l/2],
+                            p2 = lerp([r1,-l/2],[r2,l/2],abs(chamf1)/l)
+                        ) each [p1,p2]
+                    else if (is_finite(round1) && !approx(round1,0))
+                        each arc(r=abs(round1), corner=[[(round1>0?0:1e6),-l/2],[r1,-l/2],[r2,l/2]])
+                    else [r1,-l/2],
+                    if (is_finite(chamf2) && !approx(chamf2,0))
+                        let(
+                            p1 = lerp([r2,l/2],[r1,-l/2],abs(chamf2)/l),
+                            p2 = [r2-chamf2/tan(chang2),l/2]
+                        ) each [p1,p2]
+                    else if (is_finite(round2) && !approx(round2,0))
+                        each arc(r=abs(round2), corner=[[r1,-l/2],[r2,l/2],[(round2>0?0:1e6),l/2]])
+                    else [r2,l/2],
+                    [0,l/2]
+                ]
+            ) rotate_sweep(path),
+        skmat = down(l/2) *
+            skew(sxz=shift.x/l, syz=shift.y/l) *
+            up(l/2) *
+            zrot(realign? 180/sides : 0),
+        ovnf = apply(skmat, vnf)
+    )
+    reorient(anchor,spin,orient, r1=r1, r2=r2, l=l, shift=shift, p=ovnf);
+
+
 module cyl(
     h, r, center,
     l, r1, r2,
@@ -1237,7 +1407,12 @@ module cyl(
     chamfer, chamfer1, chamfer2,
     chamfang, chamfang1, chamfang2,
     rounding, rounding1, rounding2,
-    circum=false, realign=false, from_end=false,
+    circum=false, realign=false,
+    from_end=false, shift=[0,0],
+    texture, tex_size=[5,5], tex_counts,
+    tex_inset=false, tex_rot=false,
+    tex_scale=1, tex_samples,
+    tex_taper, tex_style="min_edge",
     anchor, spin=0, orient=UP
 ) {
     l = first_defined([l, h, 1]);
@@ -1245,86 +1420,76 @@ module cyl(
     _r2 = get_radius(r1=r2, r=r, d1=d2, d=d, dflt=1);
     sides = segs(max(_r1,_r2));
     sc = circum? 1/cos(180/sides) : 1;
-    r1=_r1*sc;
+    r1 = _r1 * sc;
-    r2=_r2*sc;
+    r2 = _r2 * sc;
     phi = atan2(l, r2-r1);
     anchor = get_anchor(anchor,center,BOT,CENTER);
-    attachable(anchor,spin,orient, r1=r1, r2=r2, l=l) {
+    skmat = down(l/2) * skew(sxz=shift.x/l, syz=shift.y/l) * up(l/2);
+    attachable(anchor,spin,orient, r1=r1, r2=r2, l=l, shift=shift) {
+        multmatrix(skmat)
         zrot(realign? 180/sides : 0) {
-            if (!any_defined([chamfer, chamfer1, chamfer2, rounding, rounding1, rounding2])) {
+            if (texture != undef) {
+                _textured_cylinder(
+                    l=l, r1=r1, r2=r2,
+                    texture=texture, tex_size=tex_size,
+                    counts=tex_counts, tex_scale=tex_scale,
+                    inset=tex_inset, rot=tex_rot,
+                    style=tex_style, taper=tex_taper,
+                    chamfer=chamfer,
+                    chamfer1=chamfer1,
+                    chamfer2=chamfer2,
+                    rounding=rounding,
+                    rounding1=rounding1,
+                    rounding2=rounding2,
+                    convexity=10, samples=tex_samples
+                );
+            } else if (!any_defined([chamfer, chamfer1, chamfer2, rounding, rounding1, rounding2])) {
                 cylinder(h=l, r1=r1, r2=r2, center=true, $fn=sides);
             } else {
                 vang = atan2(l, r1-r2)/2;
-                chang1 = 90-first_defined([chamfang1, chamfang, vang]);
+                chang1 = 90-first_defined([chamfang1, chamfang, vang,]);
                 chang2 = 90-first_defined([chamfang2, chamfang, 90-vang]);
-                cham1 = u_mul(first_defined([chamfer1, chamfer]) , (from_end? 1 : tan(chang1)));
+                chamf = default(chamfer, 0) * (from_end? 1 : tan(chang1));
-                cham2 = u_mul(first_defined([chamfer2, chamfer]) , (from_end? 1 : tan(chang2)));
+                chamf1 = first_defined([chamfer1, chamfer, 0]) * (from_end? 1 : tan(chang1));
-                fil1 = first_defined([rounding1, rounding]);
+                chamf2 = first_defined([chamfer2, chamfer, 0]) * (from_end? 1 : tan(chang2));
-                fil2 = first_defined([rounding2, rounding]);
+                round = default(rounding, 0);
-                if (chamfer != undef) {
+                round1 = first_defined([rounding1, rounding, 0]);
-                    checks =
+                round2 = first_defined([rounding2, rounding, 0]);
-                        assert(chamfer <= r1,  "chamfer is larger than the r1 radius of the cylinder.")
+                dy1 = abs(first_defined([chamf1, round1, 0]));
-                        assert(chamfer <= r2,  "chamfer is larger than the r2 radius of the cylinder.");
+                dy2 = abs(first_defined([chamf2, round2, 0]));
-                }
+                checks =
-                if (cham1 != undef) {
+                    assert(chamf <= r1,  "chamfer is larger than the r1 radius of the cylinder.")
-                    check = assert(cham1 <= r1,  "chamfer1 is larger than the r1 radius of the cylinder.");
+                    assert(chamf <= r2,  "chamfer is larger than the r2 radius of the cylinder.")
-                }
+                    assert(chamf1 <= r1, "chamfer1 is larger than the r1 radius of the cylinder.")
-                if (cham2 != undef) {
+                    assert(chamf2 <= r2, "chamfer2 is larger than the r2 radius of the cylinder.")
-                    check = assert(cham2 <= r2,  "chamfer2 is larger than the r2 radius of the cylinder.");
+                    assert(round <= r1,  "rounding is larger than the r1 radius of the cylinder.")
-                }
+                    assert(round <= r2,  "rounding is larger than the r2 radius of the cylinder.")
-                if (rounding != undef) {
+                    assert(round1 <= r1, "rounding1 is larger than the r1 radius of the cylinder.")
-                    checks =
+                    assert(round2 <= r2, "rounding2 is larger than the r1 radius of the cylinder.")
-                        assert(rounding <= r1,  "rounding is larger than the r1 radius of the cylinder.")
+                    assert(dy1+dy2 <= l, "Sum of fillets and chamfer sizes must be less than the length of the cylinder.")
-                        assert(rounding <= r2,  "rounding is larger than the r2 radius of the cylinder.");
+                    undef;
-                }
+                path = [
-                if (fil1 != undef) {
+                    [0,-l/2],
-                    check = assert(fil1 <= r1,  "rounding1 is larger than the r1 radius of the cylinder.");
+                    if (is_finite(chamf1) && !approx(chamf1,0))
-                }
-                if (fil2 != undef) {
-                    check = assert(fil2 <= r2,  "rounding2 is larger than the r1 radius of the cylinder.");
-                }
-                dy1 = abs(first_defined([cham1, fil1, 0]));
-                dy2 = abs(first_defined([cham2, fil2, 0]));
-                check = assert(dy1+dy2 <= l, "Sum of fillets and chamfer sizes must be less than the length of the cylinder.");
-
-                path = concat(
-                    [[0,l/2]],
-
-                    !is_undef(cham2)? (
                         let(
-                            p1 = [r2-cham2/tan(chang2),l/2],
+                            p1 = [r1-chamf1/tan(chang1),-l/2],
-                            p2 = lerp([r2,l/2],[r1,-l/2],abs(cham2)/l)
+                            p2 = lerp([r1,-l/2],[r2,l/2],abs(chamf1)/l)
-                        ) [p1,p2]
+                        ) each [p1,p2]
-                    ) : !is_undef(fil2)? (
+                    else if (is_finite(round1) && !approx(round1,0))
+                        each arc(r=abs(round1), corner=[[(round1>0?0:1e6),-l/2],[r1,-l/2],[r2,l/2]])
+                    else [r1,-l/2],
+                    if (is_finite(chamf2) && !approx(chamf2,0))
                         let(
-                            cn = circle_2tangents(abs(fil2), [r2-fil2,l/2], [r2,l/2], [r1,-l/2]),
+                            p1 = lerp([r2,l/2],[r1,-l/2],abs(chamf2)/l),
-                            ang = fil2<0? phi : phi-180,
+                            p2 = [r2-chamf2/tan(chang2),l/2]
-                            steps = ceil(abs(ang)/360*segs(abs(fil2))),
+                        ) each [p1,p2]
-                            step = ang/steps,
+                    else if (is_finite(round2) && !approx(round2,0))
-                            pts = [for (i=[0:1:steps]) let(a=90+i*step) cn[0]+abs(fil2)*[cos(a),sin(a)]]
+                        each arc(r=abs(round2), corner=[[r1,-l/2],[r2,l/2],[(round2>0?0:1e6),l/2]])
-                        ) pts
+                    else [r2,l/2],
-                    ) : [[r2,l/2]],
+                    [0,l/2]
+                ];
 
-                    !is_undef(cham1)? (
+                rotate_extrude(convexity=2) polygon(path);
-                        let(
-                            p1 = lerp([r1,-l/2],[r2,l/2],abs(cham1)/l),
-                            p2 = [r1-cham1/tan(chang1),-l/2]
-                        ) [p1,p2]
-                    ) : !is_undef(fil1)? (
-                        let(
-                            cn = circle_2tangents(abs(fil1), [r1-fil1,-l/2], [r1,-l/2], [r2,l/2]),
-                            ang = fil1<0? 180-phi : -phi,
-                            steps = ceil(abs(ang)/360*segs(abs(fil1))),
-                            step = ang/steps,
-                            pts = [for (i=[0:1:steps]) let(a=(fil1<0?180:0)+(phi-90)+i*step) cn[0]+abs(fil1)*[cos(a),sin(a)]]
-                        ) pts
-                    ) : [[r1,-l/2]],
-
-                    [[0,-l/2]]
-                );
-                rotate_extrude(convexity=2) {
-                    polygon(path);
-                }
             }
         }
         children();
@@ -1378,6 +1543,7 @@ module cyl(
 //       xcyl(l=35, d=20);
 //       xcyl(l=35, d1=30, d2=10);
 //   }
+
 module xcyl(
     h, r, d, r1, r2, d1, d2, l,
     chamfer, chamfer1, chamfer2,
@@ -1448,6 +1614,7 @@ module xcyl(
 //       ycyl(l=35, d=20);
 //       ycyl(l=35, d1=30, d2=10);
 //   }
+
 module ycyl(
     h, r, d, r1, r2, d1, d2, l,
     chamfer, chamfer1, chamfer2,
@@ -1519,6 +1686,7 @@ module ycyl(
 //       zcyl(l=35, d=20);
 //       zcyl(l=35, d1=30, d2=10);
 //   }
+
 module zcyl(
     h, r, d, r1, r2, d1, d2, l,
     chamfer, chamfer1, chamfer2,
@@ -1596,6 +1764,7 @@ module zcyl(
 //   tube(h=30, or1=40, or2=30, ir1=20, ir2=30);
 // Example: Standard Connectors
 //   tube(h=30, or=40, wall=5) show_anchors();
+
 module tube(
     h, or, ir, center,
     od, id, wall,
@@ -1673,6 +1842,7 @@ module tube(
 // Example: Generating a VNF
 //   vnf = pie_slice(ang=150, l=20, r1=30, r2=50);
 //   vnf_polyhedron(vnf);
+
 module pie_slice(
     h, r, ang=30, center,
     r1, r2, d, d1, d2, l,
@@ -1696,7 +1866,6 @@ module pie_slice(
     }
 }
 
-
 function pie_slice(
     h, r, ang=30, center,
     r1, r2, d, d1, d2, l,
@@ -1774,6 +1943,7 @@ function pie_slice(
 // Example: Called as Function
 //   vnf = sphere(d=100, style="icosa");
 //   vnf_polyhedron(vnf);
+
 module sphere(r, d, circum=false, style="orig", anchor=CENTER, spin=0, orient=UP) {
     r = get_radius(r=r, d=d, dflt=1);
     if (!circum && style=="orig" && is_num(r)) {
@@ -1789,7 +1959,6 @@ module sphere(r, d, circum=false, style="orig", anchor=CENTER, spin=0, orient=UP
     }
 }
 
-
 function sphere(r, d, circum=false, style="orig", anchor=CENTER, spin=0, orient=UP) =
     spheroid(r=r, d=d, circum=circum, style=style, anchor=anchor, spin=spin, orient=orient);
 
@@ -1884,6 +2053,7 @@ function sphere(r, d, circum=false, style="orig", anchor=CENTER, spin=0, orient=
 // Example: The dual of "icosa" features hexagons and always 12 pentagons:
 //   color("green")spheroid(r=10.01, $fn=256);
 //   spheroid(r=10, style="icosa", circum=true, $fn=16);
+
 module spheroid(r, style="aligned", d, circum=false, dual=false, anchor=CENTER, spin=0, orient=UP)
 {
     r = get_radius(r=r, d=d, dflt=1);
@@ -2194,6 +2364,7 @@ function spheroid(r, style="aligned", d, circum=false, anchor=CENTER, spin=0, or
 //   vnf_polyhedron(torus(d_min=15, od=60), convexity=4);
 // Example: Standard Connectors
 //   torus(od=60, id=30) show_anchors();
+
 module torus(
     r_maj, r_min, center,
     d_maj, d_min,
@@ -2314,6 +2485,7 @@ function torus(
 // Example(Spin,VPD=150,Med): Named Conical Connectors
 //   teardrop(d1=20, d2=30, h=20, cap_h1=11, cap_h2=16)
 //       show_anchors(std=false);
+
 module teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, l, anchor=CENTER, spin=0, orient=UP)
 {
     r1 = get_radius(r=r, r1=r1, d=d, d1=d1, dflt=1);
@@ -2432,6 +2604,7 @@ function teardrop(h, r, ang=45, cap_h, r1, r2, d, d1, d2, cap_h1, cap_h2, l, anc
 //   }
 // Example: Standard Connectors
 //   onion(d=30, ang=30, cap_h=20) show_anchors();
+
 module onion(r, ang=45, cap_h, d, anchor=CENTER, spin=0, orient=UP)
 {
     r = get_radius(r=r, d=d, dflt=1);
@@ -2527,6 +2700,7 @@ function onion(r, ang=45, cap_h, d, anchor=CENTER, spin=0, orient=UP) =
 //   text3d("Foobar", h=2, anchor=CENTER);
 //   text3d("Foobar", h=2, anchor=str("baseline",CENTER));
 //   text3d("Foobar", h=2, anchor=str("baseline",BOTTOM+RIGHT));
+
 module text3d(text, h=1, size=10, font="Helvetica", halign, valign, spacing=1.0, direction="ltr", language="em", script="latin", anchor="baseline[-1,0,-1]", spin=0, orient=UP) {
     no_children($children);
     dummy1 =
@@ -2721,6 +2895,7 @@ function _cut_interp(pathcut, path, data) =
 //   color("red")stroke(path, width=.3);
 //   kern = [1,1.2,1,1,.3,-.2,1,0,.8,1,1.1,1];
 //   path_text(path, "Example text", font="Courier", size=5, lettersize = 5/1.2, kern=kern, normal=UP);
+
 module path_text(path, text, font, size, thickness, lettersize, offset=0, reverse=false, normal, top, center=false, textmetrics=false, kern=0)
 {
   no_children($children);
@@ -2849,6 +3024,7 @@ module path_text(path, text, font, size, thickness, lettersize, offset=0, revers
 //     position(BOT+FRONT)
 //       interior_fillet(l=50, r=10, spin=180, orient=RIGHT);
 //   }
+
 module interior_fillet(l=1.0, r, ang=90, overlap=0.01, d, anchor=CENTER, spin=0, orient=UP) {
     r = get_radius(r=r, d=d, dflt=1);
     steps = ceil(segs(r)*(180-ang)/360);
@@ -2923,6 +3099,7 @@ module interior_fillet(l=1.0, r, ang=90, overlap=0.01, d, anchor=CENTER, spin=0,
 //       size=[100,100], bottom=-20, data=fn,
 //       xrange=[-180:2:180], yrange=[-180:2:180]
 //   );
+
 module heightfield(data, size=[100,100], bottom=-20, maxz=100, xrange=[-1:0.04:1], yrange=[-1:0.04:1], style="default", convexity=10, anchor=CENTER, spin=0, orient=UP)
 {
     size = is_num(size)? [size,size] : point2d(size);
@@ -3057,6 +3234,7 @@ function heightfield(data, size=[100,100], bottom=-20, maxz=100, xrange=[-1:0.04
 //       l=100, r=30, base=5, data=fn,
 //       xrange=[-180:2:180], yrange=[-180:2:180]
 //   );
+
 function cylindrical_heightfield(
     data, l, r, base=1,
     transpose=false, aspect=1,
@@ -3176,6 +3354,7 @@ module cylindrical_heightfield(
 // Example(2D,Big):  Metric vs Imperial
 //   ruler(12,width=50,inch=true,labels=true,maxscale=0);
 //   fwd(50)ruler(300,width=50,labels=true);
+
 module ruler(length=100, width, thickness=1, depth=3, labels=false, pipscale=1/3, maxscale,
              colors=["black","white"], alpha=1.0, unit=1, inch=false, anchor=LEFT+BACK+TOP, spin=0, orient=UP)
 {

vnf.scad

@@ -886,6 +886,11 @@ function _slice_3dpolygons(polys, dir, cuts) =
 //   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`
 //   atype = Select "hull" or "intersect" anchor type.  Default: "hull"
+// Anchor Types:
+//   "hull" = Anchors to the virtual convex hull of the shape.
+//   "intersect" = Anchors to the surface of the shape.
+// Extra Anchors:
+//   "origin" = Anchor at the origin, oriented UP.
 module vnf_polyhedron(vnf, convexity=2, extent=true, cp="centroid", anchor="origin", spin=0, orient=UP, atype="hull") {
     vnf = is_vnf_list(vnf)? vnf_join(vnf) : vnf;
     assert(in_list(atype, _ANCHOR_TYPES), "Anchor type must be \"hull\" or \"intersect\"");