+"vec3 rand33(vec3 p3)\n"
+"{\n"
+" p3 = fract(p3 * vec3(.1031, .1030, .0973));\n"
+" p3 += dot(p3, p3.yxz+33.33);\n"
+" return fract((p3.xxy + p3.yxx)*p3.zyx);\n"
+"}\n"
+"\n"
+"float stars( vec3 rd, float rr, float size ){\n"
+" vec3 co = rd * rr;\n"
+"\n"
+" float a = atan(co.y, length(co.xz)) + 4.0 * PI;\n"
+"\n"
+" float spaces = 1.0 / rr;\n"
+" size = (rr * 0.0015) * fwidth(a) * 1000.0 * size;\n"
+" a -= mod(a, spaces) - spaces * 0.5;\n"
+"\n"
+" float count = floor(sqrt(pow(rr, 2.0) * (1.0 - pow(sin(a), 2.0))) * 3.0);\n"
+" \n"
+" float plane = atan(co.z, co.x) + 4.0 * PI;\n"
+" plane = plane - mod(plane, PI / count);\n"
+"\n"
+" vec2 delta = rand33(vec3(plane, a, 0.0)).xy;\n"
+"\n"
+" float level = sin(a + spaces * (delta.y - 0.5) * (1.0 - size)) * rr;\n"
+" float ydist = sqrt(rr * rr - level * level);\n"
+" float angle = plane + (PI * (delta.x * (1.0-size) + size * 0.5) / count);\n"
+" vec3 center = vec3(cos(angle) * ydist, level, sin(angle) * ydist);\n"
+" float star = smoothstep(size, 0.0, distance(center, co));\n"
+" return star;\n"
+"}\n"
+"\n"