Hollywood once said that a film based on the graphic novel Watchmen could never be made—in large part because the technology to create Dr. Manhattan, the blue, glowing, matter-manipulating superhero, simply didn’t exist. The hotly anticipated film, directed by Zach Snyder, hit theaters yesterday, glowing blue man and all. Here’s how filmmakers used Frankenstein and DIY sensibilities to create a photo-real, all CG superhero.