<ol class="questions">

<li>Can you explain how to know which z coordinate to use in an unprojection? Is it written arbitrarily in our code or somehow calculated?

<li>Can you explain NDC?

<li>Can we do some example on the unprojection? It sounds cool.

    <p>It is!

<li>With a raycaster, where would we want to choose an intersected object
that is not the closest to the point?

    <p>Maybe if we want to clear everything out of our way?

<li>How does raycaster detect intersections efficiently?

    <p>Excellent question!  After the break, we'll look at the geometry
        algorithms for intersection a ray with a triangle. 

<li>Everything seems good; I think I understand so far!


</ol>