add crystal_cluster

examples/crystal_cluster.scad

@@ -0,0 +1,65 @@
+use <shape_pie.scad>;
+use <polyhedron_hull.scad>;
+use <util/rand.scad>;
+use <experimental/worley_sphere.scad>;
+
+base_r = 10;
+crystals = 10;
+crystal_cluster(base_r, crystals);
+
+module crystal_cluster(base_r, crystals) {
+	module single_crystal(r) {
+		h = r * 6;
+
+		bottom_shape = shape_pie(
+			rand(r * 0.85, r * 1.15), 
+			[rand(0, 15), rand(345, 360)], 
+			$fn = 6
+		);
+		neck_shape = shape_pie(
+			rand(r * 0.85, r * 1.15), 
+			[15, 356], 
+			$fn = 6
+		);
+
+		polyhedron_hull(
+			concat(
+				[for(p = bottom_shape) [p.x, p.y, 0]], 
+				[for(p = neck_shape) [p.x, p.y, rand(h * 0.7, h * 0.75)]],
+				[[rand(0, r * 0.1), rand(0, r * 0.1), rand(h * 0.95, h * 1.05)]]
+			)
+		);
+	}
+    
+	module rock(radius, detail) {
+		detail = detail;
+		amplitude = .25;
+		dist = "border"; 
+		
+		scale([1, 1, 0.5])
+		difference() {
+			translate([0, 0, -6.9])
+
+			translate([0, 0, 12])
+				worley_sphere(radius, detail, amplitude, dist);
+
+			translate([0, 0, -30]) 
+			linear_extrude(30)
+				square(radius * 10, center = true);
+		}
+	}
+
+
+	translate([0, 0, base_r * 0.5])
+	for(i = [0:crystals]) {
+		seed_r = base_r * rand(0, 0.75);
+		seed_a = rand(0, 360);
+		seed_pt = seed_r * [cos(seed_a), sin(seed_a)];
+
+		translate(seed_pt)
+		rotate([0, rand(0, 120 * seed_r / base_r), seed_a])
+			single_crystal(base_r - seed_r);
+	}
+
+	rock(base_r * 1.45, 1);
+}