Huang had no specific shooting plan at all and the schedule could change any time according to that of the busy stars.
Having produced many successful blockbusters such as Mummy III and The Warlords (Tou Ming Zhuang), Huang's coordination skills and planning experience helped a lot.
Even so, the veteran producer says making such a film is very challenging.
A big-name actor might only have two hours and the set had to be reserved until the star was free again. Huang remembers returning to one set nine times.
Many worry that too many famous faces may distract from the story, but Huang disagrees.
"If the stars can attract viewers, especially the young people, to cinemas, it is a victory itself," he says.
"It is like reading a book. At first, you may be attracted by the book's design but once you've finished reading, you learn something."
Moreover, he is confident of the power of the epic tale, which includes many little-known historical accounts.
For example, the Nationalists plant an undercover agent in Yan'an, Shaanxi province among Mao Zedong's entourage and bomb Mao's house with his information.
Mao takes some sleeping pills the previous night, so when soldiers come to save him he is still in a sleep.
They have to put him on a stretcher, on which the awakened Mao is shouting: "I am not leaving! I am a lucky guy! He cannot bomb me!"
Huang says as China becomes more and more open, many more confidential stories can now be told.
To make a "real film instead of a propaganda flick", Huang also tries to present genuine characters with a rich personality.
"The war will only be a background, while the characters' feeling in certain historic moments is my focus," he says.
When the film depicts Mao Zedong on the plane to Chongqing to negotiate with Chiang in 1945, it presents a nervous Mao.
"In previous films Mao must be calm on the plane, as if everything is in his control, but it is not the truth. He was feeling tension, because the future was unknown," he says.
In the film, Mao also is shown laughing like a child and drunken, when he learns he has won a war.
His daughter looks at him, as if she cannot recognize that is her father.
The refreshing portrayal also applies to the Nationalists, often depicted as arrogant and corrupt bureaucrats in previous mainland films.
Chiang slumps down on the ground when his officer tells him he had lost the war to Mao's troops, and sits still for a long while.
His son runs toward him and cries: "Father, the ground is cold." At that moment he looks just like a sad old man.
"They are people, sometimes happy, some times nervous," Huang says.
"Today you can no longer portray historical figures flat. If you go to the former office of Chiang in Nanjing, you will find hundreds of books about him sold there, including his diaries.
"It is impossible to make a propaganda film to win your viewers today."
(China Daily September 2, 2009)