Against the wishes of director Kurt Wimmer, the film was completely re-edited by the studio after they saw the original version which they apparently did not like; they saw it as 'too emotional' for the action film they were expecting and re-edited it so there would be more of an emphasis on the action and to cut it down to a PG-13 rating. The edition shortened the film from its original length of 120 minutes to 88 minutes. The director was quite angry about the edition, and many fans agree that it lowered the quality of the film significantly. An extended version of the film was later released with 6 additional minutes increasing the runtime to 94 minutes.
While on the set, Kurt Wimmer asked Milla Jovovich to punch him, in order to get a feel for the intensity she was putting in her action sequences. For the next several days, Wimmer directed the film with a black eye.
Kurt Wimmer has stated that the film was directed in such a way as to allow for an alternative theory about the story. In this theory, this the character of Six is actually Violet from the future, who comes back after a cure for hemoglophagia has been developed. This explains how Six has the cure and nobody else does. It also explains why Violet is so adamant about protecting a human, despite her goal in life being to kill them all (although she doesn't know Six is her from the future, she can just feel it). The theory also explains why Six often disobeys Violet and leads where they go. Being Violet from the future, Six remembers how things happened in the original timeline, and can prevent them from occurring this time around.
Kurt Wimmer, a comic book fan, decided to do the opening credits as a montage of "Ultraviolet" comic books, since he had always wanted to make a comic book movie. Ultraviolet itself is not a comic-book property.
A novelization of the film was written by Yvonne Navarro, with more back-story and character development. The book differs from the film in a number of ways, including a more ambiguous ending and the removal of some of the more improbable plot twists. The novel retains the plot development that was removed from the original cut of the film.
According to Rotten Tomatoes, Jovovich was not pleased with the PG-13 rated release print. She stated that she had been locked out of discussions of the film in the editing stages, and had not been allowed to see her own performance, which she felt might have been improved if she had had some input.
In early scenes, Violet changes her hair color from blue to black to purple and back to black. Also, Violet frequently wears clothes which she appears to be able to alter the color of at will and the colors change according to her mood. When Violet is getting tested for Hemoglophagia the vest she wears constantly changes colors from green, to purple, to yellow, and to red. In the fight at the Arch-Ministry's headquarters, Violet changes her suit color from white to red by the addition of blood on the palms of her gloves (which spreads over her suit). It is unknown if it is the abilities of the clothes themselves or if Violet is manipulating the clothing to switch colors.
A fictional Asian race in the film speak a fictional language (which is actually Vietnamese) known as Thaihindi and Violet is fluent in the language and thus is able to communicate with them. Coincidentally, Milla Jovovich also had to learn a fake language in another science fiction film The Fifth Element (1997).
In the film Violet buys a printed phone. The paper device has the ability to produce holographic images when attached to an extra peripheral. When combined with the extra peripheral, the printed phone is also able to trace the connection of the person on the other end. It is inconclusive, however, if this ability is of the printed phone itself or from the peripheral. Another ability from this technology is that when it is connected to the wheel of a car, it also has the ability to autopilot the car to a predetermined location. This technology has a basis in reality. In the early 21st century inkjet printer companies such as Epson demonstrated their ability to create functional circuit boards using printer technology.
In an early scene, Daxus is seen breaking a seal on, and then drinking, a hot coffee from a self-heating mug. Self-heating products, both foods and drinks, have been available in the real world for some years now, most of them using an exothermic chemical reaction to heat their contents.
Violet's first line in the film, "My name is Violet" in Violet's opening narration, is a nod to the "Resident Evil" sequels, where Milla Jovovich's character Alice's first line in the films was "My name is Alice" as she narrated the story and a recap on the events that took place in the previous films.
Gravity levelers are devices about the size of combination locks that redirect (rather than nullify or reduce) gravity, enabling a person to stand and maneuver on walls, or even ceilings. Violet uses her personal gravity leveler to ambush a squad of guards, firing on them from within a ceiling air vent. Her motorcycle is also equipped with one of these devices, enabling her to engage in a firefight with a helicopter gunship by driving up the side of a high-rise building. Precisely how this technology functions is unknown. However, visual CGI scenes from the film seem to indicate that the internal systems of the device produce an extremely high density material that produces its own gravitational pull greater than that of Earth, thus redirecting the effective 'down' direction for the object it is installed in. How this device works without severely unbalancing Earth's orbit is unknown.
In the beginning, when Violet is escorted into the building, the corridor is painted in yellow and black bands which seem to form 6 roughly equilateral triangles of alternating yellow and black: the "fallout shelter" symbol. This is not, as previously stated, the logo of the Umbrella Corporation from Resident Evil (2002). The Umbrella logo is eight red and white isosceles triangles forming an octagon.
Long before the release of the film, a teaser trailer and a rough cut of one of the action sequences leaked to the Internet after being shown to a small group. Kurt Wimmer requested that all clips be taken offline in order to keep the film mostly a secret until he decided to let it out of the bag. The clips were apparently all removed.
The 'real' pistols (as opposed to the altered props and CGI versions) are the Beretta 92-F, also known as the M-92 by the U.S. military. The rifles used, for the most part, are modified Colt AR-15's (known as the M-16 in the military).
Katarína Jancula and Mary Catherine Williams had scenes that were deleted from the final cut that were eventually restored in the unrated cut. The former plays Sharriff's new wife and the latter plays a purple haired shopper with a purple mask who is mistaken for Violet during a chase scene.
There is some confusion as to how widespread these technologies are within Violet's world. The introductory comic on the official website refers to both Dimensional Compression and Gravity Leveling as Garth's personal inventions. However, investigators in the opening scene of the movie are surprised to find flat-space technology in the enemy's possession, and Six is transported in his own personal flat-space zone. Later, police forces are equally surprised by Violet's possession of a gravity leveler. Perhaps the best compromise between these two sources of information is that Hemophage scientists belonging to the resistance developed these technologies with the help of their enhanced abilities, which were then confiscated during raids. However, the government had difficulty reverse-engineering the technology. Now that the extermination programme is nearly complete, most of these scientists are dead, therefore all of these technologies are extremely rare. This is stated explicitly in a conversation between security personnel at the lab where Violet acquires Six. Violet somersaults onto the ceiling and shoots a group of guards from above "How did she do that?!" "She must have some kind of gravity leveler!" "Well, whatever it is, it's ours now! She's not going to make it out of this complex alive!" An alternate possibility is that while the scientific basis for such devices has been established, practical devices that work outside a laboratory are still extremely rare, with Garth's devices being among the first practical examples.
Kurt Wimmer: [muzzle flash symbol] the muzzle flash on Violet's Uzi-like submachine resembles the biohazard symbol, similar to the way in Wimmer's previous movie Equilibrium (2002), that John Preston's guns have muzzle flashes that resemble the Tetragrammaton symbol.
Sometimes referred to as Flat-Space technology, dimensional compression is used to store objects in a pocket dimension. Simple objects are stored/retrieved and more complex ones systematically deconstructed/reconstructed in a flow of sparkling lights. A significant number of items can be stored for easy retrieval without burdening the user with either weight or size. The technology mainly takes the form of easily overlooked wristbands, although one-inch scabbards holding 42-inch swords are also seen. Handguns (some with 18-inch bayonets stored in their six-inch grips), and ammunition are also hidden in this manner (the bullets flying from the wristbands into the magazines on command). The technology is also used to create habitable pocket dimensions, such as the briefcase/backpack used to transport the ten-year-old Six and the semi trailer with the internal dimensions of a warehouse (containing Garth's research lab and armory). Dimensional compression is the basis of one of the light hearted scenes in the movie. A security scanner checks Violet, saying "Number of weapons found:", pauses shortly as Violet's weapons are displayed, and says "many", in an astonished voice, as it is unable to calculate the exact number. During the final battle, Daxus pulls out a sword from nowhere. This might be a result of editing, but judging by the size of Violet's pocket dimensional wristbands, Daxus's ring might have been a dimension container.
Hemoglophagia, otherwise known as the Hemoglophagic Virus or HGV, is a blood disease. It was once a rare pathogen allegedly responsible for historical accounts of vampires, but was then modified through genetic engineering by the U.S government as part of a project to create superhuman soldiers. These modifications also made the disease far more contagious, and it soon escaped into the general populace, where the media labeled its carriers "vampires", whipping the tragedy into a constant atmosphere of superstition and fear. To help suppress the fact that the quarantine procedures are actually a witch hunt, the authorities have discouraged the use of the term vampire in favor of labeling carriers of the disease Hemophages. However, there can be no doubt that the authorities are engaged in a witch hunt; in the opening scene a detective cuts his finger on a Hemophage fang and is immediately executed by his partner. Hemophages are biochemically affected by the disease in different ways and to different degrees, resulting in a remarkably wide range of abilities. Some of the abilities exhibited by hemophages are: Increased strength, speed and stamina. This could be the result of an increased level of natural hormones similar to anabolic steroids, as well as altered epinephrine (adrenalin) and norepinephrine levels. As the latter would produce an aggravated fight-flight response, this could be the reason for the hair-trigger temper of the more combat-oriented Hemophages. A rare few such as Garth develop enhanced intelligence, perhaps by increasing the number of neuronal synapses through brain cortex and parenchyma. A similar process may be responsible for the seemingly common phenomenon of enhanced senses. Violet, for example, has extremely sensitive hearing, shown to great effect during her duel with the Blood Chinois atop a skyscraper. This may be caused by the increase of the neurotransmitter load at the synaptic cleft. In the book, she also develops an enhanced sense of smell, which lets her smell the cologne and sweat of Daxus far away. As seen in the L.L.D.D. inspection room, hemophages seem to have a faster pulse and respiration capability which is higher than that of a human. One important plot point is that many hemophages have an inconveniently high sensitivity to light, accompanied by equally keen night vision. This forces them to wear heavily-tinted sunglasses in areas with vast amounts of light. In extreme cases, victims have to wear clothes and headgear that covers every bit of their skin. Violet only converted with mild photokemia, which enables her to move about more freely. Unfortunately, this, in turn, cripples her night vision. However, every hemophage exhibits the following two enhancements: Massively increased density of bone and dentin throughout the body results in slightly elongated canines, the cliched 'fangs'. These canines are slightly elongated, but certainly not the wolf-like teeth of legend. An accelerated metabolism that speeds healing. When cut, a hemophage's body automatically begins repairing the wound at a microcellular level. Although the disease has many benefits, it has two side effects: one inconvenient, one devastating: Hemophagia cripples the body's ability to regenerate blood cells. As a result, Hemophages are pale and anemic, and they require frequent blood transfusions to stay alive. All the increased cellular activity takes an unwanted toll on the carrier's body. With their metabolisms speeding along at unprecedented rates, the victims of Hemophagia have a drastically shortened lifespan. Even with the aforementioned frequent transfusions, the longest an infected individual has officially survived is 12 years. The one unofficial exception is Ferdinand Daxus. Daxus, who was infected early on, had, up to his final duel with Violet, survived a lot longer than 12 years. This was possibly due in part to his germaphobic habits, although it is more likely that he used his intimate knowledge of the HGV virus as stated in the film, and later, increasingly unlimited access to blood and blood products, along with medical resources, to prolong his life. An alternative explanation that has been put forward for his unique long-term survival is that he had discovered a cure for HGV, or at least for its more terminal effects. This is based in part on remarks made by Six after his revival that he knows the cure that can save Violet - it was discussed often in the lab he was grown in. The government, also known as the Arch-Ministry, uses the above traits to identify hemophages from the general human population. However, the 'fangs' can be filed down periodically and drugs known as meta-suppressants can be used to temporarily suppress the accelerated metabolism. Hemophage warriors use meta-suppressants to allow them to appear human when they go on covert missions that are likely to require them to undergo close inspection by security personnel and/or systems. For example, Violet first uses the meta-suppressants when entering the Laboratories for Latter Day Defense (L.L.D.D.). After exiting the inner vault with the briefcase, she injects herself with a second drug that clears the suppressants from her body. If used over an extended period of time, the body of individuals suppressing their blood characteristics through use of meta-suppresents begin to react with the drugs, which may induce vomiting, shaking, and/or other symptoms not shown in the film.