Placing a 3-D T. rex in 'Journey to the Center of the Earth'
As 3-D consultant and visual effects editor for the T. rex chase in "Journey to the Center of the Earth," Ed Marsh helped the filmmakers deal with a worry that most never consider: the physical health of the audience.
The two images visible on screen to viewers when not wearing 3-D glasses -- think of them as right eye and left eye -- had to be adjusted properly so that once the glasses were put on, the dino chasing Trevor Anderson (Brendan Fraser) wouldn't appear to be closer to the audience than to the man it was chasing.
"Small adjustments in 3-D can lead to big changes in perception," Marsh says. "With bad 3-D, [the audience's] eyes are sent through calisthenics. If things aren't perfect, it'll lead to eye strain and headaches." The dual T. rex images were slightly split to keep the carnivore back where it belonged. But moving the two T. rex images even a smidge closer together would cause the creature to appear on the same level as Fraser.
And if filmmakers attempted some kind of impossible-to-perceive M.C. Escher-style 3-D image? "You'd rip the eyes out of the audience," says Marsh. He was kidding. We think.
-- Patrick Kevin Day