html3dutil/SurfaceOfRevolution.html

<!DOCTYPE html><html xmlns:dc="http://purl.org/dc/terms/"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name="viewport" content="width=device-width"><link rel=stylesheet type="text/css" href="/style.css">
            <script type="text/x-mathjax-config"> MathJax.Hub.Config({"HTML-CSS": { availableFonts: ["STIX","TeX"], linebreaks: { automatic:true }, preferredFont: "TeX" },
                    tex2jax: { displayMath: [ ["$$","$$"], ["\\[", "\\]"] ], inlineMath: [ ["$", "$"], ["\\\\(","\\\\)"] ], processEscapes: true } });
            </script><script type="text/javascript" async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js?config=TeX-AMS_HTML-full"></script></head><body>  <div class="header">
<nav><p><a href="#navigation">Menu</a> - <a href="#top">Top</a> - <a href="/">Home</a></nav></div>
<div class="mainarea" id="top">
<h1 id="surfaceofrevolution">SurfaceOfRevolution</h1>

<p><a href="index.html">Back to documentation index.</a></p>

<p><a name="SurfaceOfRevolution"></a>
### SurfaceOfRevolution(curve, minval, maxval, [axis])</p>

<p>A surface evaluator object for a surface of revolution,
which results by revolving a two-dimensional curve around an axis.</p>

<p>This class is considered a supplementary class to the
Public Domain HTML 3D Library and is not considered part of that
library.</p>

<h4 id="parameters">Parameters</h4>

<ul>
  <li><code>curve</code> (Type: Object)<br />A curve evaluator object that describes a 2-dimensional curve to rotate about the axis of rotation, as specified in the “axis” parameter. The curve’s x-coordinates correspond to elevation, and its y-coordinates correspond to radius.</li>
</ul>

<p>If the curve function draws a curve that goes both above and below the axis of rotation, such as a circle or ellipse, the v-coordinates given in <em>minval</em> and <em>maxval</em> must restrict the curve definition to no more than half of the curve.
* <code>minval</code> (Type: number)<br />Smallest v-coordinate.
* <code>maxval</code> (Type: number)<br />Largest v-coordinate. If <em>minval</em> is greater than <em>maxval</em>, both values will be swapped.
* <code>axis</code> (Type: Array.&lt;number&gt;) (optional)<br />Axis of rotation, around which the curve will be rotated to generate the surface of revolution. If null, undefined, or omitted, the positive z-axis (0, 0, 1) will be the axis of rotation. This parameter is a 3-element array describing the x-, y-, and z-coordinates, respectively, of a 3D point. The axis of rotation will run in the direction from the origin to the point given in this parameter. This parameter need not be a <a href="tutorial-glmath.html">unit vector</a>.</p>

<h3 id="methods">Methods</h3>

<ul>
  <li><a href="#SurfaceOfRevolution_endPoints">endPoints</a></li>
  <li><a href="#SurfaceOfRevolution_evaluate">evaluate</a><br />Finds the coordinates of the specified point of this surface.</li>
  <li><a href="#SurfaceOfRevolution.fromFunction">fromFunction</a><br />Creates a surface evaluator object for a surface of revolution
whose curve is the graph of a single-variable function.</li>
  <li><a href="#SurfaceOfRevolution.torus">torus</a><br />A surface evaluator object for a torus, a special case of a surface of revolution.</li>
</ul>

<p><a name="SurfaceOfRevolution_endPoints"></a>
### SurfaceOfRevolution#endPoints()</p>

<p><a name="SurfaceOfRevolution_evaluate"></a>
### SurfaceOfRevolution#evaluate(u, v)</p>

<p>Finds the coordinates of the specified point of this surface.</p>

<h4 id="parameters-1">Parameters</h4>

<ul>
  <li><code>u</code> (Type: number)<br />u-coordinate of the surface to evaluate.</li>
  <li><code>v</code> (Type: number)<br />v-coordinate of the surface to evaluate.</li>
</ul>

<h4 id="return-value">Return Value</h4>

<p>An array containing the coordinates
of the position at the specified point. It will have three elements. (Type: Array.&lt;number&gt;)</p>

<p><a name="SurfaceOfRevolution.fromFunction"></a>
### (static) SurfaceOfRevolution.fromFunction(func, minval, maxval, [axis])</p>

<p>Creates a surface evaluator object for a surface of revolution
whose curve is the graph of a single-variable function.
The resulting surface will have a circular cross section
along its length.
Examples of surfaces generated by this technique are
cones, frustums, cylinders, spheres, and spheroids (the
bases of these surfaces won’t be generated).</p>

<h4 id="parameters-2">Parameters</h4>

<ul>
  <li><code>func</code> (Type: function)<br />Function whose graph will be rotated about the axis of rotation, as specified in the “axis” parameter. The function takes a number as a single parameter and returns a number. The return value is effectively the radius of each part of the surface from beginning to end.</li>
  <li><code>minval</code> (Type: number)<br />Smallest parameter of the function. This is a number of units from the origin along the axis of rotation.</li>
  <li><code>maxval</code> (Type: number)<br />Largest parameter of the function. This is a number of units from the origin along the axis of rotation. If <em>minval</em> is greater than <em>maxval</em>, both values will be swapped.</li>
  <li><code>axis</code> (Type: Array.&lt;number&gt;) (optional)<br />Axis of rotation, around which the function graph will be rotated to generate the surface of revolution. If null, undefined, or omitted, the positive z-axis (0, 0, 1) will be the axis of rotation. This parameter is a 3-element array describing the x-, y-, and z-coordinates, respectively, of a 3D point. The axis of rotation will run in the direction from the origin to the point given in this parameter. This parameter need not be a <a href="tutorial-glmath.html">unit vector</a>.</li>
</ul>

<h4 id="return-value-1">Return Value</h4>

<p>Return value. (Type: <a href="SurfaceOfRevolution.html">SurfaceOfRevolution</a>)</p>

<h4 id="example">Example</h4>

<p>The following creates an evaluator for a cone
which starts at the origin and runs 10 units along the z-axis.</p>

<pre>var surf=SurfaceOfRevolution.fromFunction(
function(x) {
"use strict"; return x/2; }, // use a constantly increasing function
0, 10);
</pre>

<p>This is an evaluator for the same cone, but
shifted 3 units back.</p>

<pre>var surf=SurfaceOfRevolution.fromFunction(
function(x) {
"use strict"; x+=3; return x/2; },
-3,7);
</pre>

<p>The following creates an evaluator for a cylinder
which runs from 5 to 10 units, and with a radius of 2 units.</p>

<pre>var surf=SurfaceOfRevolution.fromFunction(
function(x) {
"use strict"; return 2; }, // use a constant radius
5, 10);
</pre>

<p><a name="SurfaceOfRevolution.torus"></a>
### (static) SurfaceOfRevolution.torus(outerRadius, innerRadius, [curve], [axis])</p>

<p>A surface evaluator object for a torus, a special case of a surface of revolution.</p>

<h4 id="parameters-3">Parameters</h4>

<ul>
  <li><code>outerRadius</code> (Type: number)<br />Radius from the center to the innermost part of the torus.</li>
  <li><code>innerRadius</code> (Type: number)<br />Radius from the inner edge to the innermost part of the torus.</li>
  <li><code>curve</code> (Type: Object) (optional)<br />A curve evaluator object that describes a 2-dimensional curve to serve as the cross section of the torus. The curve need not be closed; in fact, certain special surfaces can result by leaving the ends open. If null, undefined, or omitted, uses a circular cross section with a radius of 1.</li>
  <li><code>axis</code> (Type: Array.&lt;number&gt;) (optional)<br />Axis of rotation, which the torus will pass through. If null, undefined, or omitted, the positive z-axis (0, 0, 1) will be the axis of rotation. This parameter is a 3-element array describing the x-, y-, and z-coordinates, respectively, of a 3D point. The axis of rotation will run in the direction from the origin to the point given in this parameter. This parameter need not be a <a href="tutorial-glmath.html">unit vector</a>.</li>
</ul>

<h4 id="return-value-2">Return Value</h4>

<p>Return value. (Type: <a href="SurfaceOfRevolution.html">SurfaceOfRevolution</a>)</p>

<p><a href="index.html">Back to documentation index.</a></p>
</div><nav id="navigation"><ul>
<li><a href="/">Back to start site.</a>
<li><a href="https://github.com/peteroupc/peteroupc.github.io">This site's repository (source code)</a>
<li><a href="https://github.com/peteroupc/peteroupc.github.io/issues">Post an issue or comment</a></ul>

<div class="noprint">
<p>
<a href="//twitter.com/intent/tweet">Share via Twitter</a>, <a href="//www.facebook.com/sharer/sharer.php" id="sharer">Share via Facebook</a>
</p>
</div>
<h3 id="navigation">Navigation</h3>

<ul>
  <li><a href="BSplineCurve.html">BSplineCurve</a></li>
  <li><a href="BSplineSurface.html">BSplineSurface</a></li>
  <li><a href="BufferAccessor.html">BufferAccessor</a></li>
  <li><a href="Curve.html">Curve</a></li>
  <li><a href="CurveBuilder.html">CurveBuilder</a></li>
  <li><a href="GraphicsPath.html">GraphicsPath</a></li>
  <li><a href="H3DU.html">H3DU</a></li>
  <li><a href="MathUtil.html">MathUtil</a></li>
  <li><a href="MeshBuffer.html">MeshBuffer</a></li>
  <li><a href="Meshes.html">Meshes</a></li>
  <li><a href="PiecewiseCurve.html">PiecewiseCurve</a></li>
  <li><a href="Semantic.html">Semantic</a></li>
  <li><a href="ShapeGroup.html">ShapeGroup</a></li>
  <li><a href="Surface.html">Surface</a></li>
  <li><a href="SurfaceBuilder.html">SurfaceBuilder</a></li>
  <li><a href="Transform.html">Transform</a></li>
  <li><a href="extras_camera.html">module:extras/camera</a></li>
  <li><a href="extras_camera.Camera.html">module:extras/camera.Camera</a></li>
  <li><a href="extras_camera.InputTracker.html">module:extras/camera.InputTracker</a></li>
  <li><a href="extras_createwasher.html">module:extras/createwasher</a></li>
  <li><a href="extras_curvetube.html">module:extras/curvetube</a></li>
  <li><a href="extras_curvetube.CurveTube.html">module:extras/curvetube.CurveTube</a></li>
  <li><a href="extras_derivedcurves.html">module:extras/derivedcurves</a></li>
  <li><a href="extras_evaluators.html">module:extras/evaluators</a></li>
  <li><a href="extras_evaluators.Roulette.html">module:extras/evaluators.Roulette</a></li>
  <li><a href="extras_evaluators.SurfaceOfRevolution.html">module:extras/evaluators.SurfaceOfRevolution</a></li>
  <li><a href="extras_fourierknot.html">module:extras/fourierknot</a></li>
  <li><a href="extras_gradients.html">module:extras/gradients</a></li>
  <li><a href="extras_marbleshader2.html">module:extras/marbleshader2</a></li>
  <li><a href="extras_matrixstack.html">module:extras/matrixstack</a></li>
  <li><a href="extras_matrixstack.MatrixStack.html">module:extras/matrixstack.MatrixStack</a></li>
  <li><a href="extras_moresurfaces.html">module:extras/moresurfaces</a></li>
  <li><a href="extras_moresurfaces.KleinBottle.html">module:extras/moresurfaces.KleinBottle</a></li>
  <li><a href="extras_moresurfaces.MoebiusStrip.html">module:extras/moresurfaces.MoebiusStrip</a></li>
  <li><a href="extras_pathutil.html">module:extras/pathutil</a></li>
  <li><a href="extras_randompolygon.html">module:extras/randompolygon</a></li>
  <li><a href="extras_starpolygon.html">module:extras/starpolygon</a></li>
  <li><a href="extras_superellipsoid.html">module:extras/superellipsoid</a></li>
  <li><a href="extras_superellipsoid.Supershape.html">module:extras/superellipsoid.Supershape</a></li>
  <li><a href="extras_superellipsoid.Supertoroid.html">module:extras/superellipsoid.Supertoroid</a></li>
  <li><a href="extras_torusknot.html">module:extras/torusknot</a></li>
  <li><a href="extras_torusknot.TorusKnot.html">module:extras/torusknot.TorusKnot</a></li>
</ul>
</nav></body></html>