It's very fitting that the marines are sent in to protect downtown LA from an alien invasion in Battle: Los Angeles --the enemy is a comparable militaristic one. In fact, director Jonathan Liebesman wanted to evoke Vietnam. For the creature work and mayhem, Everett Burrell (Pan's Labyrinth, Sin City), the overall visual effects supervisor, called upon several vendors to complete 1,000 shots, principally Hydraulx, Spin VFX, Cinesite, Embassy VFX, Soho VFX, Luma Pictures and Shade VFX. Burrell also made significant use of a small in-house VFX team, known as "the garage band," which contributed around 200 shots, mostly tracer fire and custom tools for rifle scope POVs.

"Jonathan wanted the aliens to be faceless with no eyes, sort of like a giant sonar dish of a head," Burrell explains. "The navy has a recon plane with a big dish on top of it that orbits around and sends signals. He wanted the head to reflect that. Underneath that skin there's something else going on, which I'm sure we'll find out in the sequel. This is just a camouflage covering that they wear, but you see little glimpses through anatomical pieces of weapons and pipes and tubing. The unique thing is that Jonathan didn't want them to be a creature; he wanted them to mimic what marines look like, so you got the vibe that the marines were fighting another military force, not a fantasy alien."

Designed by Paul Gerrard (TyRuben Ellingson designed the hardware vehicles), the aliens are split into humanoid bipedal infantry types (built by Hydraulx) and floating commander creatures (built by Cinesite) with a long body and multiple legs. These weren't your typical insect or reptile or crustacean-looking aliens: they acted like soldiers.

An early test phase overseen by Burrell with the assistance of Spin, made use of footage shot at Sony (a corporate building being rebuilt looked suitably "bombed out and destroyed"). Sony head Amy Pascal was so pleased that she signaled the next phase, which included storyboarding and previs (by POV) while script revisions were made. The film was subsequently greenlit and production took place in Louisiana the second half of 2009. Post started in early 2010.

The opening invasion, dubbed "The Travel to Santa Monica," was generated by Cinesite (which got the job based on its Emmy award-winning work on HBO's Generation Kill), and it involves the CH-46 Chinooks traveling from Camp Pendleton to Santa Monica Airport. "It showed off the scope of the destruction," Burrell continues. "The missile trail shockwaves when the meteorites are entering the atmosphere, right before they hit the water, produce a shockwave, a retro-rocket slowing down effect, and causes an iconic smoke ring."

The plate was shot with three helicopters, which Cinesite (under the supervision of Ben Shepherd) enhanced to a formation of 12 by adding CG ones. The airfield was further populated by tanks, light armored vehicles and armor, as well as atmospherics such as smoke streams and distant smoke rings.