Behind Alita: Battle Angel, How To Make Alita Birth

From 20 years ago, RMS Titanic, to 10 years ago, Avatar, to now, Alita: Battle Angel, which will be released, James Cameron, a decade-old sword, always surprises the audience.

In fact, before the release of Avatar in 2009, James Cameron had completed the screenplay of Alita: Battle Angel, but due to the high heat of Avatar, he had to plan a sequel, so the Alita: Battle Angel project was put on hold for a while.

Alita: Battle Angel is a 2019 American cyberpunk action film based on Yukito Kishiro's manga series Gunnm, written by James Cameron, directed by Robert Rodriguez, a special sci-fi blockbuster produced by Weta Digital, will be released in China on February 22. As the first Hollywood blockbuster after the Chinese New Year, it has already revealed the full potential of explosions. I believe that many card god powders are already ready to wear. The film tells about the development of science and technology after the collapse of the 26th century civilization. Human beings and mechanical reformers coexist. The weak meat is the only survival rule of the Iron and Steel City. Dr Dyson Ido is a famous reformer doctor in Steel City. He found a semi-mechanical girl's body in the garbage dump. After saving it, she named her Alita. Although Alita lost her life and lost her memory, with the help of Dr Dyson Ido and her friend Hugo, she gradually adapted to new life and street sin. By chance, Alita found himself with amazing fighting talent and was destined to be born for the battle. An epic adventure that uncovers the mystery of his own life and breaks the old order of the universe begins.

In order to restore the essence of the original comic book Gunnm, in addition to showing the cool "mechanical beauty", the film also retains the characteristics of Alita as a second-dimensional character. Weta Digital uses the new 3D shooting technology "Performance Capture" to make the full CG character Alita photo-realistic and frame the real character without any disobedience. Weta Digital special effects staff told you that the visual effects in the film have been further upgraded compared to movies such as Avatar and Rise of the Planet of the Apes. The VFX Supervisor also said that Alita is the most challenging digital role ever created by Weta Digital.

New performance capture technology How to present Alita in a real scene, James Cameron and Weta Digital Studio can be said to be painstaking. When filmed, James Cameron revolutionized the motion capture technology created in Avatar with a new “performance capture” technology – a shooting technique that can simultaneously record body movements in addition to facial expressions. In the steel city built in 1:1 real scene, a large number of cameras photographed her face and body markers against Rosa Salazar. The system will depict the markers in three dimensions and generate a set of skeletons in the CG model. Collecting the most realistic power and action data from her body to drive the CG model performance.

Rosa Salazar's performance was completely transformed into Alita, and each scar, wrinkle, and every micro-expression were strikingly consistent, achieving a mirror-like magical effect. James Cameron said: "What we are pursuing is to let the audience see the characters in the close-up is real."

Alita's big eyes and delicate skin Previously, Weta Digital had done the trick of The Lord Of The Rings, Caesar of Rise of the Planet of the Apes, and Alita's expression was the most difficult and finest. A pair of big eyes were made with 50,000 pixels, and Alita's iris used 9 million pixels. The production team spent a year to create and four months to perfect. For the first time, Eric Saindon and the team simulated the fibers of the baby's eyes. The close-up lens of the eye was not made with traditional dynamic maps, but completely created the entire eye structure including the iris.

The skin of Alita's face is also one of the challenges. To create a real face, you need to understand the "deep deconstruction" of the face. In the process, the team step by step created the head, chin, muscles and the appropriate facial epidermis, which is the fat tissue above the muscles, and then the real "skin layer." The finalization of more than 2,500 facial expressions makes up the various expressions of Alita, thus achieving the perfect integration.

47 hairs, 2700 parts To achieve Alita's unparalleled true texture, the team created 47 hair styles for eyebrows including eyebrows and eyelashes, with more than 132,000 hairs, 2000 eyebrows, 480 eyelashes on her head, face There is nearly 500,000 "peach fluff" on the ear, which is extraordinarily soft under the light. Engineers have implemented a new pore growth technique in which fluff is implanted in every pore of Alita to make the skin more delicate and firmer, and the face is more realistic.

The audience can only see the mechanical body of the metal on the screen. In fact, Alita is a simulation doll made of more than 8,000 pieces. The "mechanical skeleton" inside her body is composed of 5,000 parts of different sizes. When watching the movie, I found that all the parts of Alita were moving. When she raised her arm, the following parts followed. At the same time, the production team also designed 71 digital special effects costumes for Alita, a total of 125 different wearing methods. The Berserker's body is assembled using 2700 parts, all of which move at high speed with each movement of the character.

Nearly 500 million hours of rendering The film's Steel City takes a live-action shot in Austin, Texas, covering an area of 96,000 square feet. This huge city, built on the upper slant, requires a huge amount of computation during the rendering process. So the production team used a relatively new technology - the "OSM" caching system. First, use 1 to 20 very simple buildings as the city structure, then add "pipes" and other details to it. With the "OSM" caching system, you only need to cache once to put the buildings in different buildings. The final rendering reduces memory runs, saving time and resources.

Alita: Battle Angel Every scene takes 100 hours to render, with a total rendering of 400-500 million hours (500 frames per frame), which is 3 times that of Avatar. At Weta Digital, there are 800 staff members and 30,000 computers working together. When the weather is cold, you can even see the heat in the studio building coming out, because the computers are hot!

Currently, Alita: Battle Angel has been released besides China for many days, and the word of mouth has continued to sell. The Audience Score of Rotten Tomatoes has reached 93%. The media and industry insiders in North America also highly praised the film.