Water in sandy

Frustum clipping is a feature once unique to sandy engine, that allows you to chop parts of some mesh off without modifying it. The cool thing is that you can enable or disable this feature per object, which makes it possible to simulate scenes with simple intersections, such as scenes with things in water:

 

At the moment of writing, sandy still does not allow us to define custom clipping planes, so we have to modify one of frustum planes to achieve this effect. Full sources for this demo are available for interested people.

I used hexagon primitive by Yaniv Pe’er to model the island instead of plane primitive; the reason to do so is discussed here.