title: Method for applying physics to a complex shape
body: <p>Let's consider a platform-based structured imported as an external mesh in Three.js, and a rigid body we would like to evolve on this structure.</p>
  
  <p>My current understanding is that any object we want to apply physics on has to be approximated by one or several convex hulls which will be used for the physics computations (eg. collisions).</p>
  
  <p>Considering the platform-based structure, let's assume these are only parallelepipeds, so creating <code>Ammo</code> shapes around them is trivial. Hence, creating the whole world physics is just a matter of iterating over the objects and creating as many <code>Ammo.btBoxShape</code>.</p>
  
  <p>But now, suppose we want to add a hollow on of the platforms (or for instance a pothole on a road).
  What would be the recommended approach to make the physics world include these hollows?</p>
  
  <p>Should a custom <code>Ammo</code> shape be built? Considering the expected result, it can't be a preposterous need, but it seems I'm lacking beginner skills in this domain because I can't find any hint about how to do this...</p>
  
  <p>So any help will be greatly appreciated!</p>