For the CGI used throughout the film, companies Rhythm & Hues (R&H) and Industrial Light & Magic (ILM) developed different parts of the film. R&H focused on the animation of the animals, while ILM completed the final scene of the ark rushing through Washington D.C. Lindy De Quattro, the ILM associate visual effects supervisor, revealed that "This is the first time where we had to do a whole series of shots that were happening mid-day, where you were going to get a really long look at the water and what it was doing." The company initially experienced problems creating the water effects and had to develop new tools which would choreograph the movements of the water. In addition, ILM used similar tools that were used on their prior film "Poseidon". Lighting was also an issue as the characters on the ark had been filmed on a greenscreen stage, and the visual effects company had to ensure that the lighting matched that of the characters and the outside setting. Details were added to the ark for long-distance shots to make the design of the ark more appealing and relate the ark's size to scale in comparison to the amount of water. To complete the scene, ILM used thirty to sixty crew members and produced 200 shots over a yearlong period between April 2006 and May 2007.