title: How to calculate volume of supported material from STL file?
body: <p>I have a STL files that contains 3d model of basic ball and another 3d model of some weird block. 
  I was given the task of finding out volume of model and the possible supported Material?
  This is how I calculate.</p>
  
  <p>BoundingBox Volume = lenght x width x depth  (values are got from stl file)</p>
  
  <p>Volume of Model is based on</p>
  
  <pre><code>        var v321 = (v3.x) * (v2.y) * (v1.z),
          v231 = (v2.x) * (v3.y) * (v1.z),
          v312 = (v3.x) * (v1.y) * (v2.z),
          v132 = (v1.x) * (v3.y) * (v2.z),
          v213 = (v2.x) * (v1.y) * (v3.z),
          v123 = (v1.x) * (v2.y) * (v3.z);
          return (v231 - v321 - v132 - v213 + v123 + v312) / 6.0;
  </code></pre>
  
  <p>(these values are from STL file) and seems correct.</p>
  
  <p>Now How do I calculate the support material volume ? </p>