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Sphere primitive
authorScott Worley <ScottWorley@ScottWorley.com>
Sat, 29 Dec 2012 07:33:47 +0000 (23:33 -0800)
committerScott Worley <ScottWorley@ScottWorley.com>
Sat, 29 Dec 2012 07:33:47 +0000 (23:33 -0800)
nt3d.js patch | blob | blame | history
sphere_primitive.html [new file with mode: 0644] patch | blob

diff --git a/nt3d.js b/nt3d.js
index 239b03c214afed2d58de96070d8a5982870be677..28766983fe33341b262ee572f4a09fc01d917d4c 100644 (file)
--- a/nt3d.js
+++ b/nt3d.js
@@ -62,6 +62,27 @@ nt3d = {
                return this.closed_trianglefan([apex].concat(base)).concat(
                       this.trianglefan(base.reverse()));
        },
                return this.closed_trianglefan([apex].concat(base)).concat(
                       this.trianglefan(base.reverse()));
        },
+       sphere: function(center, radius, latitude_steps, longitude_steps) {
+               return this.oriented_sphere(center, radius, [0,0,1], [1,0,0], latitude_steps, longitude_steps);
+       },
+       oriented_sphere: function(center, radius, north, greenwich, latitude_steps, longitude_steps) {
+               var unit_north = this.unit(north);
+               var north_pole = this.translate_point(this.scale(unit_north,  radius), center);
+               var south_pole = this.translate_point(this.scale(unit_north, -radius), center);
+               return this.spheroid(north_pole, south_pole, radius, greenwich, latitude_steps, longitude_steps);
+       },
+       spheroid: function(north_pole, south_pole, radius, greenwich, latitude_steps, longitude_steps) {
+               var delta = this.sub(north_pole, south_pole);
+               var path = [];
+               for (var i = 0; i < latitude_steps-1; i++) {
+                       path.push(this.translate_point(south_pole, this.scale(delta, (1-Math.cos(Math.PI*i/(latitude_steps-1)))/2)));
+               }
+               path.push(north_pole);
+               function shape(i) {
+                       return nt3d.circle(radius*Math.sin(Math.PI*i/(latitude_steps-1)), longitude_steps);
+               }
+               return this.extrude(path, shape, delta, greenwich);
+       },
        shapenormals_from_closed_path: function(path) {
                return function(i) {
                        var prev = (i == 0) ? path.length-1 : i-1;
        shapenormals_from_closed_path: function(path) {
                return function(i) {
                        var prev = (i == 0) ? path.length-1 : i-1;
diff --git a/sphere_primitive.html b/sphere_primitive.html
new file mode 100644 (file)
index 0000000..0e5095a
--- /dev/null
+++ b/sphere_primitive.html
@@ -0,0 +1,18 @@
+<html>
+  <head>
+    <title>Sphere primitive</title>
+    <script type="text/javascript" src="nt3d.js"></script>
+    <script type="text/javascript">
+      function sphere_primitive(radius, lattitude_steps, longitude_steps) {
+       return nt3d.sphere([0,0,0], radius, lattitude_steps, longitude_steps);
+      }
+      var params = [["Radius", 1],
+                    ["Lattitude steps", 20],
+                    ["Longitude steps", 20]];
+    </script>
+  </head>
+  <body onload="nt3d.framework(sphere_primitive, params)">
+    <h1>Sphere primitive</h1>
+    <p>There's a sphere primitive.</p>
+  </body>
+</html>
In-browser 3D-printing modeling framework