Rodeo FX was once again called upon to create exceptional environments and immersive 3D matte paintings. However, Rodeo's CG contributions were much larger than on any previous motion picture. In addition to environment work, ILM trusted Rodeo FX to create, simulate, and animate fully CG creatures and vehicles for a variety of sequences. Rodeo FX was also responsible for all the variations of the interior Robot Head shots, which included building and animating a complex CG rig used to control the actions and movements of the robots – a seamless photo-real blend of both CG and practical FX.

 

More here : http://www.rodeofx.com/all-films/pacific-rim