An early draft of the script, written by Jonathan Hensleigh in August 1997, had Bruce Banner performing experiments with gamma-irradiated insect DNA on convicts, transforming them into insect-men whom the Hulk then battles.
Creating the Hulk in CGI was one of the most complex tasks Industrial Light & Magic had ever undertaken at that time. The computer model used 12,996 texture maps, and required 1,165 muscle movements and one hundred layers of skin. It took the combined work and efforts of about one hundred eighty ILM technicians (sixty-nine technical artists, forty-one animators, thirty-five compositors, ten muscle action animators, nine CG modellers, eight supervisors, six skin painters and five motion-capture wranglers), over two and a half million hours, and one and a half years for him to be effectively created and portrayed in the film. With all of that work, some of the public complained that the Hulk looked too fake, comparing him with Shrek (2001).
According to the animators at Industrial Light & Magic, the Hulk weighs 3,452 pounds (1,565.8 kilograms), and can exert fourteen tons of pressure per square inch. His skin is ten times as strong as Kevlar. His chest measures seventeen feet and four inches (5.3 meters), his waist twelve feet and ten inches (3.3 meters), his foot four feet and three inches (1.3 meters), and his neck six feet and nine inches (2 meters). If he wore shoes, they would be (U.S.) size eighty-seven. He can move at a top speed of three hundred miles (four hundred eighty-three kilometers) per hour, and cross three to four miles (4.8 to 6.4 kilometers) in a single jump.
Jennifer Connelly was attracted to the role of Betty Ross, since she found Ang Lee's vision of the Hulk interesting: "He wasn't talking about a glossy fun-filled kids' movie about a green guy running around in tights. He was talking along the lines of tragedy and psychodrama, the green monster of rage, greed, jealousy, and fear in all of us."
Ang Lee employed the split-screen technique to cinematically mimic the panels of a comic-book page. This required many takes of one scene, which was draining for Eric Bana. It took him four takes to film Banner's first Hulk transformation, and by the time of its completion, he was on the verge of collapse.
In this movie, the madder the Hulk gets, the larger he becomes. The first time he appears, he is nine feet (2.7 meters) tall, the second time, he is twelve feet (3.6 meters) tall, and the third time, he is fifteen feet (4.5 meters) tall. His skin would also be colored grayish-green in his first appearance, and afterwards remain greenish. The ILM animators thus had to create three distinctly different Hulks.
The amount of CGI involved in the Hulk's battle against the three mutant dogs was one of the hardest, most complicated scenes ILM had ever done. Ultimately, what ended up on-screen was only one third of what was originally storyboarded. To have filmed all of it would have been simply too expensive.
Eric Bana commented that the mood during shooting was "ridiculously serious and morbid." Director Ang Lee explained to him that he was shooting a sort of superhero tragedy, and he would be making a whole other movie about the Hulk at the Industrial Light & Magic studios. Ironically, the film was criticized as being an overly serious superhero film.
During Banner's first transformation as the Hulk, he destroys most of the laboratory in which he works. When he lifts the gamma sphere onto his back and shoulders, the Hulk poses for a brief moment like the Greek mythological figure Atlas; who holds the sphere of the earth on his back and shoulders. This is a nod towards the name of the location of the actual gamma sphere, which exists, in real-life, in A.T.L.A.S. (Argonne Tandem Linear Accelerator) at Argonne National Laboratory in Argonne, Illinois.
This film was rebooted as The Incredible Hulk (2008) with the intention of the character fitting within the Marvel Cinematic Universe. However, as Marvel has the production rights to make a film with the Hulk, Universal Pictures still maintains distribution rights to any film starring the character in his own solo film. Thus, The Incredible Hulk was produced by Marvel Studios, but Universal Pictures distributed it.
According to Director Ang Lee, the film's screenplay drew influences from monster tales like King Kong (1933) and Frankenstein (1931); fantasies like Dr. Jekyll and Mr. Hyde, Beauty and the Beast, and Faust; and most particularly Greek mythological tragedies.
When the first transformation of Banner into Hulk occurs, the color of the Hulk is either gray or greenish-gray. This is an homage to the first appearance of the Hulk, when he was actually gray in his debut comic (May 1962). The publisher couldn't do gray very well, so Stan Lee changed the color to green, simply because green hadn't been used much by other characters. From the second transformation, he maintains his prominent emerald hue.
During production in San Francisco, California, filming had to be stopped for about two hours because some college students from UC Berkeley were playing a prank and systematically urinating in porta-potties, creating very loud peeing sounds that distracted the cast members on-set. It took about two hours to round up all of the students.
To prepare for his role as General Thaddeus E. "Thunderbolt" Ross, Sam Elliot read the Hulk comic books. He had doubts about growing a moustache, since the Army doesn't encourage facial hair, but was convinced by Ang Lee to do so.
ILM wanted to study a human performing the actions Hulk does in order to create his movements. Initially they tried this using body-builders, but found them to be too cumbersome. Instead, they settled for personal trainers.
In the scene where Betty goes to David Banner's house to inquire about Bruce, there is a brief shot of a reptile in an aquarium, a gila monster. This is a nod towards The Incredible Hulk (1978) season one, episode nine, "The Incredible Shrinking Hulk", in which a laboratory accident shrinks Bruce down to a minute size. He then transforms into the Hulk and ventures across the desert, where he encounters and does battle with a gila monster that, compared to his miniature size, is gigantic.
This film features the only combat missions ever flown (albeit simulated and fictional) by the RAH-66 Comanche stealth helicopter, whose program was canceled a year after the film's premiere with only two copies built.
According to Ang Lee's DVD commentary, the dogfight scene in the woods was originally envisioned with the Hulk fighting the monster dogs while naked. However, this was thought to be too difficult for a PG-13 movie, and so the Hulk doesn't appear naked until the very end of the fight.
The gamma sphere in the film actually exists, located in A.T.L.A.S. (Argonne Tandem Linear Accelerator) at Argonne National Laboratory in Argonne, Illinois. However, it has no gamma-generating capabilities.
When Betty first meets David Banner, they discuss a man named Benny. Benny was a soldier who appeared in the Hulk graphic novel "The Dogs of War" which introduced the concept of Hulk dogs (which appear in this film). Pictures from the same novel are flipped by the screen when the opening Marvel logo appears.
A rollercoaster at Universal Studios theme park is based on this movie. This is especially noticeable when entering the cars of the ride. The platform is designed to look like the interior of the underground labs where Bruce Banner is taken to after being drugged. In the movie, after Talbot is killed, the Hulk escapes to a control room that he begins to destroy. General Thaddeus E. "Thunderbolt" Ross instructs one of the soldiers to light the tunnel to "Show him the way out". This control room and tunnel are the same design used on the rollercoaster, with the tunnel being the accelerating climb that begins the ride.
This movie was released ten years after the death of Bill Bixby. He was mostly remember for his portrayal of Doctor David Bruce Banner in The Incredible Hulk (1978), which ran from 1978 to 1982 (five seasons and three television movies). The character's name is actually Robert Bruce Banner, but was changed to one of his aliases for television.
The helicopters that attack the Hulk in the desert are RAH-66 Comanches. The jets he fights near the Golden Gate Bridge are F/A-22 Raptors. At the time of the film's release, neither aircraft were in active service with any branch of the U.S. Military. The RAH-66 program has subsequently been scrapped (on February 23, 2004), with no helicopters ever entering active service.
The Abrams tanks that confront the Hulk in the desert are in fact former British Army Chieftain tanks that were dressed to represent the Abrams. The mock-ups are very convincing and quite difficult to spot. The Chieftain has six wheels per side, whereas the Abrams has seven.
The unit patch on General Ross' (Sam Elliott's) uniform is that of the 7th Cavalry Division. This the same unit to which his character, Sergeant Major Basil Plumley, was assigned in We Were Soldiers (2002).
After the Hulk knocks out Talbot and leaps away, the Hulk creates a ripple in a puddle next to Talbot. According to Ang Lee, this was an homage to Jurassic Park (1993), which was directed by Steven Spielberg. Eric Bana (Bruce Banner) worked with Spielberg in Munich (2005).
The trivia item below may give away important plot points.
Throughout the film, there are clues which foreshadow David Banner's climactic descent into villainous insanity: David goes undercover as a janitor in his son's lab, a reference to Samuel Sterns, a janitor who became the Hulk's archnemesis, "The Leader"; David bombards himself with gamma radiation and takes on the properties of anything he touches, like the Absorbing Man, another enemy of the Hulk; David absorbs, and transforms into, a LOT of electrical energy in the film's final sequence, an homage to the classic Hulk villain Zzzax.