projects / nt3d / blame
| Commit | Line | Data |
|---|---|---|
| 9ff1b1e6 SW |
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> |