add worley_sphere

src/experimental/worley_sphere.scad

@@ -0,0 +1,46 @@
+use <sweep.scad>;
+use <util/rand.scad>;
+use <noise/nz_worley3s.scad>;
+use <ptf/ptf_rotate.scad>;
+
+$fn = 192;
+
+radius = 30;
+amplitude = 20;
+sample_scale = 0.05;
+dist = "border"; // [euclidean, manhattan, chebyshev, border]
+grid_w = 1;
+	
+worley_sphere(radius, amplitude, sample_scale, grid_w, dist);
+
+module worley_sphere(radius, amplitude, sample_scale, grid_w = 1, dist = "border", angle_boundary = 180 / $fn, seed = undef) {
+    sd = is_undef(seed) ? rand() * 1000: seed;
+	a_step = 360 / $fn;
+
+	sections = [
+	    for(a = [-90 + angle_boundary:a_step:90 - angle_boundary])
+		let(p = [radius * cos(-a), 0, radius * sin(-a)])		
+			for(a = [0:a_step:360 - a_step])
+			ptf_rotate(p, a)
+		
+	];
+
+    nz = nz_worley3s(sections * sample_scale, sd, grid_w, dist);
+	noisy_sphere = [
+			for(i = [0:len(nz) - 1])
+			let(
+				p = sections[i],
+				p2d = [p[0], p[1]],
+				noisyP = p2d + p2d / norm(p2d) * nz[i][3] * amplitude
+			)
+			[noisyP[0], noisyP[1], p[2]]
+	];
+
+	sweep([
+	    for(i = [0:$fn:len(noisy_sphere) - $fn])
+		[
+		    for(j = [0:$fn - 1])
+			noisy_sphere[i + j]
+		]
+	]);
+}