Against the ink black backdrop of the night sky, thousands of hovering drones set off fireworks resembling falling teardrops at a recent show in Liuyang, Hunan province.

Videos of the fireworks display quickly amassed interest online, with more than 700 million views on social media.

The inspiration for the show, called Tears from the Door of Heaven, came from Huang Jiayi, a high school student in Liuyang.

Her grandfather, Huang Weide, is the founder of Qingtai Fireworks, a local fireworks company.

Huang Weide's mother, Huang Jiayi's great grandmother, died at an early age, leaving behind no photographs.

To recognize this sadness, Huang Jiayi came up with the idea of making a fireworks display that resembled tears, making them drop through a halo made of drones to express the deep feeling of missing lost family members.

The show lasted about 15 minutes. In the finale, artificial intelligence was used to create an image of Huang Weide's mother walking toward a picture of him and giving him a hug.

Xun Chang, head of publicity at Qingtai Fireworks, said the company's engineers worked hard to make the granddaughter's idea a reality. Drones used for fireworks have become commonplace in Liuyang, a city renowned for its fireworks industry.

Liuyang is one of China's four major fireworks-producing areas, with a history of fireworks dating to the Tang Dynasty (618-907), when Li Tian, a Liuyang native, is believed to have invented the world's first firecrackers.

He used them to drive away evil spirits.

Liuyang is the world's largest production hub for firecrackers and fireworks, with domestic sales accounting for 50 percent of the national total and exports sent to more than 100 countries and regions. Since last year, fireworks shows have been held at the Sky Theater during weekends and festivals by local fireworks companies, and the recent show by the company was one of them, Xun said.

She added that the shows have brought lots of visitors to Liuyang, and tickets have been extremely popular.

Xun said the popularity of the show has exceeded the company's expectations, and has provided a boost for the peak sales seasons during the New Year and Spring Festival holidays, she said.

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