| | 1 | <html> |
| | 2 | <head> |
| | 3 | <title>Wrap Sphere</title> |
| | 4 | <script type="text/javascript" src="nt3d.js"></script> |
| | 5 | <script type="text/javascript"> |
| | 6 | function wrap_sphere(sphere_radius, extrusion_radius, turns, circle_angle, aspect_ratio, distortion_angle, steps_around, steps_along) { |
| | 7 | // Spiral path along sphere surface |
| | 8 | var path = []; |
| | 9 | for (var i = 0; i < steps_along; i++) { |
| | 10 | var progress_0to2 = i / (steps_along/2); |
| | 11 | var progress_0to1andback = progress_0to2 < 1 ? progress_0to2 : 2 - progress_0to2; |
| | 12 | var progress_neg1to1andback = progress_0to1andback * 2 - 1; |
| | 13 | var z = progress_neg1to1andback * sphere_radius; |
| | 14 | var r = Math.sqrt(sphere_radius*sphere_radius - z*z); |
| | 15 | var phase_adjust = progress_0to2 < 1 ? 0 : Math.PI; |
| | 16 | var x = r*Math.cos(progress_0to1andback*turns*2*Math.PI + phase_adjust); |
| | 17 | var y = r*Math.sin(progress_0to1andback*turns*2*Math.PI + phase_adjust); |
| | 18 | path.push([x,y,z]); |
| | 19 | } |
| | 20 | |
| | 21 | // Shape to be extruded |
| | 22 | var shape = nt3d.circle(extrusion_radius, steps_around); |
| | 23 | shape = nt3d.rotate_about_origin(shape, [0,0,1], circle_angle*Math.PI*2); |
| | 24 | for (var i = 0; i < shape.length; i++) { |
| | 25 | shape[i][0] *= aspect_ratio; |
| | 26 | } |
| | 27 | shape = nt3d.rotate_about_origin(shape, [0,0,1], distortion_angle*Math.PI*2); |
| | 28 | |
| | 29 | return nt3d.closed_extrude( |
| | 30 | path, |
| | 31 | shape, |
| | 32 | nt3d.shapenormals_from_closed_path(path), |
| | 33 | nt3d.pathnormals_from_point(path, [0, 0, 0])); |
| | 34 | } |
| | 35 | var params = [["Sphere radius", 100], |
| | 36 | ["Extrusion radius", 5], |
| | 37 | ["Turns", 3], |
| | 38 | ["Angle of circle (in turns) (useful when steps_around is small)", .125], |
| | 39 | ["Aspect ratio", 2], |
| | 40 | ["Angle of distortion (in turns)", .25], |
| | 41 | ["Steps around", 4], |
| | 42 | ["Steps along", 500]]; |
| | 43 | </script> |
| | 44 | </head> |
| | 45 | <body onload="nt3d.framework(wrap_sphere, params)"> |
| | 46 | <h1>Wrap Sphere</h1> |
| | 47 | <p>Extrude something in a spiral along the surface of a sphere.</p> |
| | 48 | </body> |
| | 49 | </html> |
projects / nt3d / blame_incremental