The BCC Caustics filter can be used to simulate the effect of light
refracting through a surface of water and projected onto a surface (like
moving water ripple reflections on a pool bottom).
You can use this filter to create many types of effects where rays emanate from
a point and are reflected or refracted by a curved surface. For example, you
could use this filter to generate:
The built in PixelChooser, with integrated mocha planar tracking allows for
greater control over which areas of the image the filter should affect.