added partial extrusion for faster headband rakes, small changes

bezier_extrusion.scad

@@ -3,10 +3,38 @@ module extrusion(points){
   n = len(points);
   k = len(points[0]);
   points_new = [for(L = points) for(p = L) p];
-  faces = concat([[for(i = [0 : k-1]) i], [for(i = [1 : k]) (n*k)-i]],      concat([for (i = [0 : n-2]) for (j = [0 : k-2]) [(i*k)+j+1, (i*k)+j, ((i+1)*k)+j, ((i+1)*k)+j+1]],  [for (i = [0 : n-2]) [i*k,(i+1)*k-1,((i+2)*k)-1,(i+1)*k]]));
+  faces = concat([[for(i = [0 : k-1]) i], [for(i = [1 : k]) (n*k)-i]], 
+          concat([for (i = [0 : n-2]) for (j = [0 : k-2]) [(i*k)+j+1, (i*k)+j, ((i+1)*k)+j, ((i+1)*k)+j+1]],  [for (i = [0 : n-2]) [i*k,(i+1)*k-1,((i+2)*k)-1,(i+1)*k]]));
   polyhedron(points = points_new, faces = faces, convexity = 10);
 }
 
+module slice(points){
+  k = len(points[0]);
+  points_new = [for(L = points) for(p = L) p];
+  faces = concat([[for(i = [0 : k-1]) i], [for(i = [1 : k]) 2*k-i], [0,k-1,(2*k)-1,k]], [for (i = [0 : k-2]) [i+1, i, k+i, k+i+1]]);
+  polyhedron(points = points_new, faces = faces, convexity = 10);
+}
+
+module bezier_extrude_partial(ctrl, shape, gap = 1, mod = function (t) 1, mod_x = function(t) 1, mod_y = function (t) 1, sections = 128){
+  B_0 = ctrl[0];
+  B_1 = 3*(-ctrl[0] + ctrl[1]);
+  B_2 = 3*(ctrl[0] - 2*ctrl[1] + ctrl[2]);
+  B_3 = -ctrl[0] + 3*(ctrl[1] - ctrl[2]) + ctrl[3];
+  function bezier(t) = B_0 + t*B_1 + (t^2)*B_2 + (t^3)*B_3;  
+    
+  Bn_0 = [B_1.y,-B_1.x];
+  Bn_1 = [2*B_2.y,(-2)*B_2.x];
+  Bn_2 = [3*B_3.y,(-3)*B_3.x];
+  function normal(t) = Bn_0 + t*Bn_1 + (t^2)*Bn_2;
+    
+  slices = [for (i = [0 : sections]) 
+            let (t = i/sections, p = bezier(t), normal = normal(t), n = normal/norm(normal))  
+           [for (v = shape) [p.x+(mod(t) * mod_x(t) * n.x * v.x),p.y+(mod(t) * mod_x(t) * n.y * v.x), mod(t) * mod_y(t) * v.y]]];
+  for(i = [0 : 1+gap : sections-1]){
+      slice([slices[i],slices[i+1]]);
+  }
+}
+
 module bezier_extrude(ctrl, shape, mod = function (t) 1, mod_x = function(t) 1, mod_y = function (t) 1, sections = 128){
   B_0 = ctrl[0];
   B_1 = 3*(-ctrl[0] + ctrl[1]);
@@ -28,4 +56,4 @@ module bezier_extrude(ctrl, shape, mod = function (t) 1, mod_x = function(t) 1,
 shape = [[0,0.5],[0.8,0],[0.5,-1],[-0.5,-1],[-0.8,0]];
 ctrl = [[0,0],[20,10],[0,20],[10,0]];
 wave = function (x) 0.75+0.25*cos(3*360*x);
-bezier_extrude(ctrl = ctrl, shape = shape, mod = wave, sections = 8192);
+bezier_extrude_partial(ctrl = ctrl, shape = shape, mod = wave, sections = 32);

catears.scad

@@ -1,7 +1,7 @@
 use <bezier_extrusion.scad>;
 use <headband.scad>;
 
-thickness = 2.5;
+thickness = 2.7;
 height = 5.5;
 
 module catear(){
@@ -17,10 +17,9 @@ module catear(){
                 [-thickness/2,height/2-0.5],
                 [-thickness/2+0.5,height/2],
                 [thickness/2-0.5,height/2]];
-  union(){
+    
-    bezier_extrude(ctrl = ctrl_ear1, shape = shape_band, sections = 32);
+  bezier_extrude(ctrl = ctrl_ear1, shape = shape_band, sections = 32);
-    bezier_extrude(ctrl = ctrl_ear2, shape = shape_band, sections = 32);
+  bezier_extrude(ctrl = ctrl_ear2, shape = shape_band, sections = 32);
-  }
 }
 
 module catears(){

dogears.scad

@@ -1,7 +1,7 @@
 use <headband.scad>;
 use <dogear.scad>;
 
-thickness = 2.5;
+thickness = 2.7;
 
 module dogears(rightear = "flop", leftear = "flop"){
   union() {
@@ -21,4 +21,4 @@ module dogears(rightear = "flop", leftear = "flop"){
   }
 }
 
-dogears(rightear = "lflop");
+dogears();

headband.scad

@@ -1,7 +1,7 @@
 use <bezier_extrusion.scad>;
 
 module headband(thickness, height){
-  rake_length = 2.5;
+  rake_length = 3;
 
   shape_band = [[thickness/2,height/2-0.5],
                 [thickness/2,-height/2+0.5],
@@ -16,20 +16,31 @@ module headband(thickness, height){
                 [0,height/2],
                 [rake_length,height/2-2],
                 [rake_length,-height/2+2]];
+    
+  shape_halfband = [[thickness/2,height/2-0.5],
+                    [thickness/2,-height/2+0.5],
+                    [thickness/2-0.5,-height/2],
+                    [0,-height/2],
+                    [0,height/2],
+                    [thickness/2-0.5,height/2]];
          
   ctrl_band = [[21,0],[77,56],[56,126],[0,126]];
-  ctrl_end = [[21,0],[20,-1],[18,-4],[17,-10]];
+  ctrl_end = [[21,0],[20,-1],[18,-4],[17,-8]];
   ctrl_rake = [[-52,86],[-40,139.5],[40,139.5],[52,86]];
-  fillet = function (t) (t < 0.75) ? 1 : sqrt(1-((4*t)-3)^2)/1.5 + 0.33;
-  rake = function (t) (-cos(64 * 360 * t) > 0.33) ? 1 : 0.1;
 
   union(){
     bezier_extrude(ctrl = ctrl_band, shape = shape_band, sections = 64);
     mirror([1,0,0]) bezier_extrude(ctrl = ctrl_band, shape = shape_band, sections = 64);
-    bezier_extrude(ctrl = ctrl_end, shape = shape_band, mod_x = fillet, sections = 16);
+    bezier_extrude(ctrl = ctrl_end, shape = shape_band, sections = 16);
-    mirror([1,0,0]) bezier_extrude(ctrl = ctrl_end, shape = shape_band, mod_x = fillet, sections = 16);
+    translate([17,-8]){
-    bezier_extrude(ctrl = ctrl_rake, shape = shape_rake, mod_x = rake, sections = 512);
+      rotate_extrude(convexity = 10, $fn = 16) polygon(shape_halfband);
+    }
+    mirror([1,0,0]) bezier_extrude(ctrl = ctrl_end, shape = shape_band, sections = 16);
+    translate([-17,-8]){
+      rotate_extrude(convexity = 10, $fn = 16) polygon(shape_halfband);
+    }
+    bezier_extrude_partial(ctrl = ctrl_rake, shape = shape_rake, gap = 2, sections = 3*64+1);
   }
 }
 
-headband(thickness = 2.5, height = 5.5);
+headband(thickness = 2.7, height = 5.5);