Example of <a href="https://en.wikipedia.org/wiki/ray-tracing" class="extiw" title="w:ray-tracing">ray-tracing</a> to demonstrate <a href="https://en.wikipedia.org/wiki/refraction" class="extiw" title="w:refraction">refraction</a>; left half of pool is filled with water material, right half is empty.
<a href="//commons.wikimedia.org/wiki/User:Ldo" title="User:Ldo">Ldo</a>
2013-07-09 15:23:05
<span class="int-own-work" lang="en">Own work</span>