title: How to use CSGTree for multiple boolean operations
body: <p>I'm trying to make use of <a href="https://libigl.github.io/tutorial/#csg-tree" rel="nofollow noreferrer">Csg Tree</a> by libigl to do multiple boolean operations at once. In the linked tutorial, there is just this one line:</p>
  <pre class="lang-cpp prettyprint-override"><code>// Compute result of (A ∩ B) \ ((C ∪ D) ∪ E)
  igl::copyleft::cgal::CSGTree&lt;MatrixXi&gt; CSGTree =
    {{{VA,FA},{VB,FB},&quot;i&quot;},{{{VC,FC},{VD,FD},&quot;u&quot;},{VE,FE},&quot;u&quot;},&quot;m&quot;};
  </code></pre>
  <p>I couldn't figure out how to use the <a href="https://github.com/libigl/libigl/blob/682e4b9685d2737215f6629ecafcb318d714d556/include/igl/copyleft/cgal/CSGTree.h#L27" rel="nofollow noreferrer"><code>CSGTree</code> class API</a>. Can anybody help ideally by a boilerplate example?</p>