I recently re-watched Battleship and what I thought was pretty cool about the film was that rigid body and water simulation! There’s a scene where the aliens comes out of the water and destroys everything in it’s path and that looked pretty cool and I know it takes a shit load of hard work to do.Of course the awesome people behind the VFX of Battleship was none other than Industrial Light & Magic (ILM). There were over a thousand shots of VFX to be done and part of it involved some sort of water simulation.
Three years before Battleship’s release, ILM had already started discussion on the water sims pipeline. They had a well-developed water sims pipeline which was used in Poseidon, as well as Pirates of the Caribbean. However, they had to step it up a notch and reinvent their water sims due to time constraint. Thus, ILM started on what they would internally call the Battleship Water Project. Together with their R&D team, they came up with a new water pipeline and advanced tools to improve their workflow. The following picture shows the layer breakdown.
It would probably bore you to explain how they did eventually went around doing the water sims pipeline so I shall not go so much detail into that. Basically, their problem was that since the scene was an open sea scene, large water simulation on a level set particle based process was needed and they broken everything down into grids and optimize them. However when the millions of cells of the alien ship interacted and collided with the water geometry, a lot of fine details in the complex water structures was lost from the simulation as the grid size on screen was perhaps only a two foot square compared to real world.
Thus to counter this problem, ILM added on top a type of FLIP PIC solver for particle based simulation which allowed finer detailed solution. This gave the traditional approach an allowance for wider scales. Each of these particle groups would then have a grid placed around them. Developed by ILM themselves, the secondary grids added to the particles are adaptive in size, and calculated based on how close the camera was to the particle simulation. Now with the particle secondary solution, the imagery could be resolved to a pixel resolution.
Check out the rendered product below!