Secrets of the Heavenly Book [Photo provided to China Daily]

The Shanghai studio suggested that Chinese artists rewrite the tale, based on the Ming Dynasty (1368-1644) fantasy Pingyao Zhuan (Legends of Conquering Monsters).

The BBC agreed but later quit the project over financial concerns.

Having already taken advantage of one third of total funding, the Shanghai studio decided to fully finance the movie and assigned Qian and Wang Shuchen, another veteran animator, to codirect the feature.

Looking for inspiration, Qian and the crew went to Chengde, Hebei province, where China's largest surviving royal garden and some Qing Dynasty (1644-1912) royal temples are located. They stayed there for more than two months, interviewing monks and sketching ancient complexes.

Thanks to its blend of Chinese culture, impressive characters and light moments, Secrets of the Heavenly Book has been hugely popular since it premiered in 1983.

It has been rebroadcast many times, and on China's popular film reviewing site Douban.com it has a rating of 9 out of 10.

But the fortunes of Shanghai Animation Film Studio, most of whose productions were box office hits until the 1990s, began to wane as China began to rapidly change about 25 years or so ago.