When it came to depicting the eponymous alien from Paul, actor/co-writer Simon Pegg was very clear about what he wanted: the iconic gray creature with an enormous head, big eyes and spindly limbs. In other words, very familiar with hints of Close Encounters of the Third Kind and E.T., which was fitting since Steven Spielberg makes a hilarious cameo on the phone with Paul.
"Right off the bat, Simon envisioned it as a turn away effect so Paul wouldn't stand out," remarks Anders Beer (Hellboy II: The Golden Army ), the animation supervisor from Double Negative, who collaborated with Jody Johnson, the visual effects supervisor. "He didn't want him romanticized in any way; he didn't want him to be a cartoon or a creature effect. He said many times that it cannot be Jar Jar Binks."
They eventually arrived at a design they liked, which was sculpted by Spectral Motion. But given that this was an indie buddy comedy about two geeky Brits (Pegg and Nick Frost) and their close encounters with an iconoclastic alien (voiced by Seth Rogen) outside Area 51, the options were limited.
"We had to make some compromises with the design, specifically the eyes," Beer continues. "They wanted a dark, penetrating look, but it was too creepy. It was hard to connect with it and make eye lines work. We went with eyes that are more naturalistic: they've got an iris and a pupil.
Double Negative, therefore, came up with an appropriate animation pipeline for the 300 shots, using a team of about 30 animators. "What I came up with was a brain trust with a couple of leads and the head of animation at Double Negative [Eamonn Butler]," Beer says. "It revolved around reference. We had Nick and Simon and a rough geography laid out on a soundstage floor in Culver City and we had Seth in a Xsen Moven suit [based on inertial sensors]; and we had three high-def witness cameras. We basically rehearsed the whole film for about four days on a stage before principal photography. It was a great starting point to calibrate ourselves to Seth Rogen. It was also a great start for the editorial side because they didn't have the budget to do full-CG previs.
"In the end, we didn't use any of the MoCap data. We were still steered for the very specific design. It was a low-budget film about shooting in a traditional sense and the weather affected everything. I was on location with the crew for three months in Santa Fe and other locations in New Mexico, shooting for a character that wasn't on set. We had puppets and other stand-ins (a bunch of titanium rods with adjusters and ping-pong balls). We shot clean passes at everything, and, when the actors interacted with Paul, we used things that were minimally invasive and cleaned up the plate later.
DNeg provided two ways of shooting reference for the animators: using a Flip camera and having them mess around in the moven suit. "So the animators would put the suit on and capture their performance in 3D. Even though it wouldn't match perfectly with Paul, we could get a rough performance. We dumped the capture onto an early Paul rig and have it in the scene file for the animator to manipulate. They could show this previs style, MoCap session. It was a real coup. Here they really flexed their creative muscles to come up with the right performance for Paul. We boiled it down to three or four takes, showed it to the client and progressed from there. Later we increased performance fidelity and added facial animation. The client wanted us to test the limits of the performance. They empowered us to try things out."
They used Maya  with proprietary rigging and created their own user interface for the animators called Muppet with a library of poses to stay on model. They also used Nuke  and PRMan; the proprietary Squirt for smoke; and Houdini  for other particle effects. "We relied on a lot of heavy lifting from matchmove, lighting and comp to ensure Paul was seated believably in the plate. It was a very collaborative process and in some cases Paul's level of interaction was such that comp had to manipulate the actors and props in the plate. (painting in new eye lines, replacing hidden body parts and set pieces)."
The director, Greg Mottola (Adventureland, Superbad), had never done a vfx film before, but Beer says he took to it immediately. "We showed him rough animation with no facial on it or a lot of noise in it with the moven suit," Beer adds. He understood where we were headed and gave us good, articulate direction.
"If Paul works, it's in large part thanks to us; if he doesn't, it's in large part thanks to us."
Bill Desowitz is senior editor of AWN & VFXWorld.