add perlin_sphere

src/experimental/perlin_sphere.scad

@@ -0,0 +1,30 @@
+use <util/rand.scad>;
+use <noise/nz_perlin3s.scad>;
+use <experimental/geom_icosahedron.scad>;
+
+// radius = 30;
+// detail = 4;
+// amplitude = 10;
+// period = 20;
+	
+// perlin_sphere(radius, detail, amplitude, period);
+
+module perlin_sphere(radius, detail, amplitude, period = 10, seed = undef) {
+    points_faces = geom_icosahedron(radius, detail, quick_mode = false);
+	points = points_faces[0];
+	faces = points_faces[1];
+
+	sd = is_undef(seed) ? rand() * 1000: seed;
+    noisy = nz_perlin3s(points / period, sd);
+
+	noisy_points = [
+		for(i = [0:len(points) - 1])
+		let(
+			p = points[i],
+			nz = noisy[i]
+		)
+		p / norm(p) * (radius + nz * amplitude)
+	];
+	
+	polyhedron(noisy_points, faces);
+}