add climbing_rose

examples/spiral/climbing_rose.scad

@@ -0,0 +1,108 @@
+use <experimental/foliage_scroll.scad>
+use <polyline_join.scad>
+use <stereographic_extrude.scad>
+use <sweep.scad>
+use <util/choose.scad>
+use <util/reverse.scad>
+
+$fn = 12;
+width = 200;
+height = 200;
+max_spirals = 4; 
+angle_step = 360 / $fn; 
+min_radius = 15; 
+init_radius = rands(min_radius * 2, min_radius * 3, 1)[0];
+
+theta_step = 0.1;
+rf_step = 0.1;
+
+climbing_rose();
+
+module climbing_rose() {
+    thickness = 0.02;
+
+    theta_from = PI * 1.75;
+    theta_to = PI * 15;
+
+    rf_to = 1;
+    module rose(thickness, theta_from, theta_to, rf_to, rf_step) {
+        function phi(theta) =
+            (PI / 2) * exp(-theta / (8 * PI));
+            
+        function wave(theta) = 
+             1 - 0.5 * pow(1.25 * pow(1- ((3.6 * theta) % (2 * PI)) / PI - (theta > 0 ? 0 : 2), 2) - 0.25, 2);
+
+        function g(rf, theta) =
+            let(angle = phi(theta) * 57.2958)
+            1.95653 * pow(rf, 2) * pow(1.27689 * rf - 1, 2) * sin(angle);
+
+        function r(rf,theta) = 
+            let(angle = phi(theta) * 180 / PI)
+            wave(theta) * (rf * sin(angle) + g(rf, theta) * cos(angle));
+
+        sf = 1 + thickness;
+        sections = [
+            for(theta = [theta_from:theta_step:theta_to])
+            let(
+                path = [ 
+                    for(rf = [0.1:rf_step:rf_to])
+                    let(
+                        r = r(rf,theta),
+                        angle = theta * 57.2958, 
+                        angle2 = phi(theta)* 57.2958,
+                        x = r*sin(angle), 
+                        y = r*cos(angle),
+                        z = wave(theta)*(rf*cos(angle2)-g(rf,theta)*sin(angle2))
+                    )
+                    [x, y, z]
+                ]
+            )
+            concat(
+                [
+                    for(p = path)
+                    [p[0] * sf, p[1] * sf, p[2]] - [0, 0, thickness]
+                ],
+                reverse(path)
+            )
+        ];
+        
+        sweep(reverse(sections));
+    }
+
+    module draw(spirals) {    
+        r = spirals[0][0] / 5;
+        for(i = [0:len(spirals) - 1]) {
+            rr = r * ((len(spirals) - sqrt(i == 0 || i == 1 ? .5 : i)) / len(spirals));
+            path = spirals[i][1];
+            
+            polyline_join(path)
+            rotate([45, 0, 0])
+                sphere(rr, $fn = 4);
+                
+            
+            center = spirals[i][2];
+            
+            for(i = [0:1]) {
+                p = choose(path);
+                
+                v = (p - center);
+                a = atan2(v.y, v.x);
+                
+                translate([each p, 0] + [0, 0, rr * 0.55])
+                
+                rotate([0, 15, a])
+                rotate(a)
+                scale(rr * 2.75) 
+                union() {
+                    rose(thickness, theta_from * 3 * r / rr, theta_to * r / rr, rf_to, rf_step);
+                    translate([0, 0, .075])
+                        sphere(.1);
+                }
+                }
+        }
+    }
+
+    spirals = foliage_scroll([width, height], max_spirals, init_radius, min_radius);
+
+    draw(spirals);
+}