ILM built the models in the new Transformers movie to withstand scrutiny in IMAX theaters.  The process, with all of the gory details, is cataloged over at StudioDaily.

There’s a sequence in DreamWorks/Paramounts’ Transformers: Revenge of the Fallen in which the Devastator, a gigantic Decepticon robot, scales an Egyptian pyramid as easily as a gorilla climbing a tree and rips off the top. With over 52,632 parts and nearly 12 million polygons, the robot is the biggest model Industrial Light & Magic has built in its 30 years of model-making. And they built the bot for IMAX shots.

via ILM Builds the Bots for IMAX Shots in Transformers Sequel | Film & Video.