Zhang Yimou rarely scored a full score, and the image algorithm and naked-eye 3D opened the feast of scientific and technological aesthetics of the Winter Olympics

On the evening of February 4, the "Virtual Bird's Nest" of the National Stadium was presented for the first time at the Beijing 2022 Winter Olympic Games, bringing the ultimate enjoyment of hundreds of millions of viewers around the world. This is also the world's first large-scale application of 8K technology for live broadcast of the opening ceremony and coverage of key events.

When talking about the opening ceremony, Zhang Yimou, the general director of the opening and closing ceremonies of the Winter Olympics, said in the Zhihu Q&A that in the past, we (the opening ceremony) did not come to line up with hundreds of people, neat and uniform, as if they would all say "not good acting." Now, we dare not "show muscles", no longer show off, not limited to good looks, but to think about what can most impress people. "As a creator, I'm usually reluctant to rate myself, but I'm going to give a 100 to the team at last night's opening ceremony!" Zhang Yimou said at a news conference.

With the support of technology, the Winter Olympics created an ethereal and romantic sense of modern technology with only 3,000 participants, and artificial intelligence, 5G, AR, naked-eye 3D, cloud computing, 8K display, digital twins and simulation technology were widely used in the opening ceremony performance.

The "light and shadow technology force" behind the rise of the five rings

At the opening ceremony of this Winter Olympic Games, the "Yellow River water" flowing down, the "ice cube" that condensed instantaneously, the fluttering snowflakes on the ice surface and the five Olympic rings constituted the first climax.

"The director has been asking us to find the confidence of oriental culture in the content of light and shadow." Wang Zhiou, visual effects director of the opening and closing ceremonies of the Winter Olympics, said.

Taking the formation of the water waterfall as an example, in the process of creation, in addition to finding a large number of materials to analyze and learn from the water, Wang Zhiou's visual team also used image processing algorithms to machine learn a large number of traditional Chinese ink paintings and establish a model of ink texture characteristics, so as to create the artistic conception of "the water of the Yellow River comes from heaven".

Subsequently, when the water of the Yellow River slowly froze, forming an "ice cube" nearly 3 stories high, the symbols of the previous Winter Olympic Games were also carved out one by one with the laser engraving knife.

"This time we made the world's only 360-degree naked-eye 3D digital device, and also did a lot of virtual digital rehearsals, so that everyone can feel the luster of the water cube when it rises." In laser engraving, a point information is needed, and we give the digital content to the laser console to make it fully synchronized, requiring tens of thousands of pictures. Finally, through digital programming and self-developed programs, all the laser points in the ice cube were converted into digital information. Wang Zhiou wrote in the Zhihu Q&A that these pictures that used to require lighting engineers and laser engineers to go to physical proofreading overnight have now become a direct digitized engineering information, ensuring that the imagined laser and humanoid tracking are perfectly presented in the ice cube at the first time, not bad for a second.

In order to make the ice breaking of the ice cube more accurate, the Long March Tianmin development team, which is responsible for the stage support work of the opening ceremony of the Winter Olympics, in the case of limited venues, drives 4 sets of synchronous transmission units composed of 16 chains and 16 steel wire ropes by precisely controlling the motor, so that the total weight of about 400 tons and the lifting weight of 180 tons of the ice cube lifting and positioning accuracy is controlled at ± 1mm.

In the design of the stage mechanical control system, the above team added the digital simulation software and hardware equipment used in the development of aerospace system products, the optimization design of the control algorithm, and the semi-physical simulation test test. Compared with the general rocket flight test, nearly 100 ground tests are required, and the stage system of the Winter Olympics has carried out nearly 1,000 ground tests.

In addition, in order to achieve a dazzling effect on the stage floor, the stage floor of the opening ceremony adopts the largest 8K ultra-high-definition ground display system, which is provided by the domestic screen company BOE. The ground display system uses a total of 40,000 LED screens, and the total length of cables used in the entire venue is more than 20 kilometers, setting a Guinness World Record.

"Snowflake" shaped main torch stand: a combination of virtual and realistic

At the opening ceremony, the most eye-catching giant "snowflake" shaped main torch platform shone with a crystal clear light and slowly lifted into the air, and nearly 100 virtual snowflakes with the names of the participating areas also began to gather together, along with the lighting of the sacred flame, pushing the entire atmosphere of the opening ceremony to a climax.

Zhang Yimou said that snowflakes are like an "undercover", from the countdown to the children singing "thousands of snowflakes competing to open", snowflakes have been there. "For the first time in the history of the Centennial Olympic Games, there is such a main torch, the names of all participating countries and regions are on it, it is composed of the whole world, no matter the size of the fire, it is the fire in our hearts. Different snowflakes from all over the world gather in Beijing to become a snowflake common to mankind. ”

In order to realize the creative concept of "diamond sparkling" of the torch stand, the main creative team of the opening ceremony applied some digital visual programming methods to the design and production process. "Made of Chinese knots and olive branches, it is woven into a snowflake, the snowflake device is 14.899 meters wide, and there are 96 small snowflakes of Chinese knots inside, surrounded by 6 olive branches, each of which is a luminous device." Wang Zhiou said that mapping the digital programming algorithm to the snowflake device can make its light completely different every second, both the blooming feeling of the snowflake and the romance of the olive branch.

The entire torch stand has a total of more than 550,000 LED lamp beads, each of which is independently controlled by a single channel driving the chip.

At the same time, the flowing snow and wind dissipated in real time under the feet of skaters, and more than 500 children laughed and played on the stage like crystal snowflakes. Behind the technology is the 3DAT computer vision motion capture technology provided by Intel and the AI real-time video special effects technology provided by the teachers and students of the Beijing Film Academy Sound School.

Intel said that through the AI algorithm, through 4 cameras to cover the entire Winter Olympics, and let the actors and the scene laid out to achieve real-time interaction, in terms of transmission efficiency, from image acquisition, recognition to detection and processing only need less than a few tens of milliseconds.

At the moment when the torch is lit, the giant snowflake screen radiates from the center to the surroundings, shining out a wave of layers of brilliant light, behind the rapidly changing display screen, the use of BOE AIoT technology system and independent research and development of the same / asynchronous compatible letter and hair system, asynchronous centralized control can quickly send large-scale video content in a very short period of time, synchronous centralized control to ensure that 102 double-sided screens to achieve millisecond response, in addition, "main road + loop" The highly redundant control system backed up ensures the ultra-high reliability of the flare station broadcast control system.

In Zhang Yimou's view, the biggest feature of the opening ceremony is innovation. It has a lot of creative points, it's not the biggest scale, it's not the most performed, but the creative idea shows the warmth of human beings in a difficult time.