Pang has proved his admirers turned detractors wrong with Love in the Buff. Premiered on Wednesday as the opening film of the Hong Kong International Film Festival, the feature - which will be released next Thursday - sees the first film's two protagonists, advertising executive Jimmy Cheung (played by Shawn Yue Man-lok) and cosmetics saleswoman Cherie Yu (Miriam Yeung Chin-wah), split up, but somehow come back together after moving separately to Beijing for work.

Rather than offering melodramatic high jinks and endless sequences showcasing Beijing's hypermodern urban landscape - two things which litter mainland romantic comedies of the past few years - Love in the Buff is comparatively restrained, drawing its humour from the way the two Hongkongers consolidate themselves in Beijing through personal and professional relationships they establish there.

Buff is also the latest Hong Kong film to have turned the statutory requirements of these co-productions to its advantage, by providing alternative accounts of cross-cultural issues and experiences to the usual social narrative seen in the mass media. Pang's look at Hongkongers lost in Beijing can also be seen as a counterpart to Johnnie To Kei-fung's Don't Go Breaking My Heart, which explores a mainland-born investment analyst's difficulties in settling into her life in Hong Kong after breaking up with her boyfriend.

While Pang says he has never questioned his ability to deliver a nuanced Buff, he still recalls how he once steered clear of co-productions, when he was making his distinctly local movies like A.V. (2005) and Exodus (2007). 'I was once like the ordinary film-goer who felt really frustrated by watching yet another unsatisfactory outing of that kind,' he said. 'As a filmmaker I was quite worried. If none of my esteemed predecessors could cut it, why should I be able to overcome these challenges?

'So I thought about what the problems were with those failed films. And you're bound to fail if you are just thinking, in very abstract terms, what people like and dislike there. So I thought if I were really to develop my career on the mainland, I couldn't just do one-off assignments. I need to just up my roots and move myself in there.'

And he did, physically, by relocating with his wife to Beijing two years ago. He said he learned the ropes in the capital by working as a producer of, first, an online omnibus of short horror films and then of an as-yet unreleased film starring Yue and Zhang Jingchu. It was when he finally finished writing the screenplay of Love in the Buff last May that he felt ready to finally take his plunge in directing a film in Beijing.

Pang is adamant that there is much creative leeway for Hong Kong filmmakers to navigate, despite the authorities' close scrutiny of politically and socially sensitive issues.

'So it is that they've got a list of types of content you can't touch - but you can always make good films out of the types you can,' he said. 'If what I felt like doing was on the could-do list, why shouldn't I do a co-production which will bring me better financial resources and actors?'

Devoid of the incessant smoking in the previous instalment (and the nudity suggested in the title), Love in the Buff was certainly deemed a safe investment for China Film Media Asia, the joint mainland production and distribution venture of Beijing's China Film Group and Hong Kong's Media Asia.

Pang says Buff only represents one approach in what he describes as plans for a 'twin-forked' career, with the other path being represented by Vulgaria, a low-budget and edgy satire about a down-and-out filmmaker's struggle to secure financial backing for his project. It's a journey which will see him meeting mainland gangsters and kick-starting a remake of a 1970s porn movie - two topics which are clearly taboo up north.

Unlike Buff, Vulgaria - which takes its bow at the film festival next Tuesday before its commercial release in June - was filmed in Hong Kong with Hong Kong money. 'It would be a real sell-out if I was to make something like Vulgaria and then try to get it released on the mainland,' he said. 'That would be a disaster waiting to happen. If you try to force your way through, you'll end up cutting the whole film to pieces, and driving away the audience who would originally have loved Vulgaria as it is.'

While Pang acknowledges that fewer investors are audacious enough to put up money for projects which can't be shown in mainland cinemas, he also says the success of the Taiwanese You Are The Apple of My Eye - which broke box-office records at home and in Hong Kong - has reignited a desire for investors to divert a small part of their budget for mid- or low-budget projects.

'As long as you get them to hear the sound of ringing tills, they will be in,' Pang said. 'They will think of how they could just allocate this really small bit of the pie to these smaller films, hoping the bet will come off.'

While he hopes for a change in the mindset of investors, Pang also says Hongkongers need to adjust their localised way of seeing the world.

'I think everyone should look beyond Lei Yue Mun,' he said. 'We've grown up thinking Hong Kong is at the centre of the world. It isn't. And it's not just about looking towards the mainland and the market it boasts of - you can always look elsewhere, towards other directions.'

'It's no longer a credit to just say you're from Hong Kong,' continued the director, who will begin shooting his first solely mainland-funded production, an adaptation of the novel Spoilt Women Have the Best Lives, in the summer.

'You wouldn't just get a job [on the mainland] simply because of that [being from Hong Kong] - these days, they look at us as individual cases. And in film, the younger generation on the mainland knows much more about film history and language than we might expect - don't ever think of us still having an edge over them today.'