Hong Kong action star Donnie Yen has long held the reputation of being a difficult person to work with.
But Teddy Chan, who directed him in Bodyguards And Assassins (2009) and more recently in Kung Fu Jungle, describes him as a "conscientious and very mature person who simply wants to do the best work".
They have a good working relationship because both are equally involved in the storytelling behind every action sequence, Chan says in Mandarin.
"I'm not the action coordinator but I don't want my action scenes to be there for no reason. I need to set up the who, what, where, when and why it needs to be in the story," he adds.
"And that's what gets Donnie excited. If I tell him, we're just going to do a fight scene in a bar, that would be so boring, right? But what if I say that the fight threatens to shoot them out of the bar, which is on the 36th floor, and the stairs to escape are all rusty and about to crumble and it's raining outside? He'll be like, 'Wow, that is so difficult', but he's actually really excited and he'll start making phone calls on how it can be done."
Chan, 57, was speaking to Life! at an interview in Hong Kong to promote Kung Fu Jungle, his new action flick. In the film, Yen plays a jailed gongfu master who helps the police on a case in exchange for a shortened prison sentence.
Over the last few years, the 51-year-old actor has made headlines for allegedly being demanding and unreasonable on set. He was embroiled in an intense public war of words in 2012 with Chinese actor Vincent Zhao, who was cast to co-star alongside him in Special ID, for which he was producer.
Zhao left the project after claiming that Yen made too many last-minute script changes, even reducing all of Zhao's scenes in order to hog the limelight.
Veterans, including director Benny Chan and gongfu actors Sammo Hung and Hung Yan Yan, have also reportedly found Yen a pain to work with.
Director Chan waved off the rumours, saying: "The entertainment circle is called that for a reason - it's a circle, so everything comes full circle. Which means that no one can possibly hate or love anyone else forever.
"When I wanted to film Bodyguards And Assassins, someone told me he'd never produce it because he didn't believe in it. But 10 years later, we're working together on another project and every- thing's fine between us. I'll never say I can never work with someone again because that's just not possible in showbiz. Everything has to do with timing and chance as well."
One person who worked out for him precisely due to good timing and chance is Chinese actor Wang Baoqiang, the second lead in Kung Fu Jungle.
The 30-year-old actor, who starred in Chinese blockbuster comedy Lost In Thailand (2012), plays the movie's villain, a gongfu-obsessed man whose goal is to take down every top gongfu expert in town, particularly Yen.
"Wang is primarily known as a comedian, so I wouldn't have thought of him until Donnie suggested him to me," Chan says with a laugh. "His suggestion reminded me of when I first met Wang at a film premiere more than 10 years ago.
"Wang said he liked watching my action movies and added that he had gongfu training as a child in Shaolin. Before I could say anything, he jumped up and started showing me his moves."
So Chan sent a memo to Wang and adds: "He was on the verge of forgetting about gongfu because no one had hired him for it. My offer came at the perfect time."
So does he think Wang has sufficiently delivered on the action sequences?
Chan says: "When I showed the film to some Chinese investors, they said, 'Wang Baoqiang doing action? Really?' But after watching it, they gave him the thumbs up. So all I can say is, watch the movie and find out for yourself."
Kung Fu Jungle is showing in cinemas now.