The first challenges in this sequence came about on set. Johnson says Sandler's costume included a full-length duster jacket that had to look like it was floating in the zero gravity environment. Johnson also says they had to create a shorter jacket, cut off at the waist and with tracking markers attached to it, so they could create a CG coat for the weightless shots.

The sequence was prevised by the production, with a postvis process used to place a simple geometry of the sequence into each shot about 15 minutes after it was shot.

Fuel VFX created a sequence in which gumballs fall from the sky. The sequence required Fuel to add in many more gumballs than were used on set, and to make them interact with other objects.

Johnson adds that the design of the space station was left open for his crew to make specific. "I flew back to London for a week or so and worked with a team, and we basically just brainstormed a bunch of different ideas," he explains. "We were given kind of free rein for everyone to use their imaginations. I had maybe about 10 guys coming up with different designs of what it could be. We had a few kind of key ideas, like maybe Flash Gordon would be a look, the kind of late '70s, early '80s Flash Gordon; maybe 2001 was a look; Star Wars was a look." Artwork was prepared for all these ideas and presented to Shankman, who helped Cinesite refine the look to the point it could be built in the computer and the geometry fleshed out.

The final look had to evoke realism, Johnson continues. "It all had to basically make sense in the sense that if there was a staircase, you needed to know how the staircase was going to attach itself to the wall, where it would attach to the bleachers, whether there was a doorway that made sense," he says. "We tried to make it a fantasy basketball court. I was going to Staples Center a lot and taking a lot of photographs and looking at these sports stadiums online."

The other element that had to be developed was the alien creature Sandler's character fights in this scene. Originally envisioned as a kind of scary monster with fangs, it was decided fairly late in the game to go for a more comedic look and redesign the creature. The final result was a mucous-covered, slightly transparent alien dubbed the "booger monster."

"We were trying to come up with something universal, that every 9-year-old boy would find funny -- and boogers was obviously fairly high up that list," says Johnson. "The fangs and teeth went away and we had to kind of smother the creature in this goopy, mucousy stuff that would kind of fly off and interact with everything."

The creature required a number of dynamic simulations -- one for the creature itself and another one created in Houdini for its gooey covering.

Another interesting effect was the creation of a red horse for one sequence -- an effect achieved on set by actually painting a white horse red. However, a few additional shots required the use of a different horse, this one with a brown coat that had to be repainted digitally to match the look of the painted white horse, Berton says.

Sydney-based Fuel VFX created a key sequence in which Sandler's character encounters gumballs falling from the sky. The sequence required Fuel to add in many more gumballs than were used on set, as well as to make them interact with other objects correctly and match the color of the real gumballs.

"We did a lot of work on those shots to really make sure the gumballs all look right, they all shadowed each other, they bounced off of each other," Berton says. "We even got things bouncing off of Adam Sandler and off of his umbrella."

Fuel also contributed a CG shot of the hotel evolving and getting built up over a 30-year span. Berton says the final shot is amazing for all the detail Fuel packed into it.

"They just did all the research and put in billboards from the '70s that transform into billboards from the 21st century, and the building's going up and there's airplanes flying through the sky, there's freeways being built and the cars racing along, all imitating the look of time lapse photography but all actually created synthetically."

A completely different challenge was creating Bugsy, the children's comic-relief guinea pig with the gigantic eyes. Tippett Studio was in charge of this character, which posed some unusual challenges. The character had to look photoreal, cartoony at the same time.

"We were working in an environment where what was funny about Bugsy wasn't what he really did, it was just how he looked," Berton says. "Every time we tried to make him more characteristic, he became less funny. So we had to really keep our focus on how to make his eyes look funny in every shot."

Lola VFX contributed some head replacements: in particular, for one sequence in which Sandler was injured and his stunt double stepped in. "We reshaped the stunt double's face to match Adam's," says Edson Williams, supervisor of the facility's work. "We had to move the jaw line, adjust the thickness of the neck and shoulders, reduce the prominent chin, add 5 o'clock shadow and change the hairline."

Other facilities working on the film were Whiskytree, Rotofactory and Look Effects.