Tippett infused human features into Draco's face to make it mammalian rather than reptilian; his muzzle was designed to be a mixture of a highland gorilla and a human mouth to accommodate his dialogue. Draco's face was designed to resemble Sean Connery's after his casting. Cohen also drew ideas from nature, such as the boa constrictor's jaw structure, horses' musculature, and retractable teeth. Tippett also considered how Cohen would frame the scenes involving Draco, the size difference between Draco and the human actors, and what he would do throughout the film. Tippett and his crew created a five-foot model of Draco for lighting reference and an articulated model used as a reference for Draco's poses. It took five months for four modelers to make Draco's digital model with ILM's Alias software. Originally, Draco's scales and wings would have an iridescent quality; it is visible in some scenes but mostly not. His wingspan was initially calculated as 125 ft to support his body but halved to 72 ft to be practical enough to fit on the sets. His eyes were also more detailed and dilated. Those were some of the design elements dropped because of software issues, running out of time, and wanting to make Draco as realistic as possible and not too fantastical. To aid animators so that Draco's performance resembled Connery as much as possible, Cohen made an extensive library of reference footage with hundreds of Connery images from his filmography up to that point, categorized by his displayed emotion. Dragonheart is the first film to use ILM's Caricature software, developed to help lip-sync Draco's animation to Sean Connery's voiceover work; programmer Cary Phillips received the Academy Scientific and Technical Achievement Award for creating the software. The film is notable for having the first realistic CG dragon in film, and Draco is the first dragon ILM made capable of human speech. Filming Preproduction on Dragonheart began on January 17, 1994, while principal photography began in July in Slovakia, scheduled to end in November. During sequences with Draco and Bowen, visual effects supervisor Scott Squires and his teams used what they called a "monster stick"—a pole with a bar and two red circles at the top—as an indicator for where Draco's eyes would be for Quaid's reference. They also set up speakers through which Cohen would read Draco's lines for Quaid, which Quaid said that it "helped [him] out a