Copyright Blue Sky Studios.
Every so often an assignment comes along for which great effort is expended in development, but which ultimately gets cut or drastically reduced in the final film. The shoreline on the beach in Rio is such an assignment.
It is tempting to develop an effect like this beyond what is required to complete the shot work, because these types of "pure FX" assignments are very appealing. However, as with any effect, the ability to discern what is important and what can be discarded is most valuable to directors and producers.
This particular wave was an exercise in economy, due to a couple of factors:
1) The directors desired something ambient and unobtrusive.
2) FX was grappling with a problem in which renders would fail if the wave doubled over onto itself even slightly (i.e., a curling wave). Resolution of the render issue would require a major effort from the R&D department.
Because the directors desired simplicity, we deemed it appropriate to accept the render limitation and abandon the development of "breaking" action into the rig. Hence, the wave always crests into a vertical wall but never quite forms into a curl, instead dissipating and spilling onto the shore.
The wave is composed of a series of 2-dimensional "ribs" lofted together, very similar to the "Robots" domino wave. The surface animates cyclically, expanding and contracting as ocean waves do. The cycle at the shoreline is much slower than that at the source, serving to conceal the cycle without incurring more complexity.
Alen Lai did a lot of great work with the materials, as well as providing a method by which to stitch the animating patch onto the ocean behind it seamlessly.
This clip chronicles the development of the wave. At the end are 3 shots in which the wave appears, albeit briefly.