Director Kevin Smith had a good run in the ’90s. From Clerks to Dogma, he made four feature films in five years. He never broke through to big box office sales, but established himself with his “View Askewniverse,” the world in which his recurring characters are periodically filmed. Even in movies not set in this universe, Smith’s work is linked by a common theme or mode-mixing raunchiness with sentimentality.

For a long time, it was thought that this mode was unmarketable to an audience beyond what Smith had already garnered. In 2005, Judd Apatow came on the scene with The 40-Year-Old Virgin, which propelled the scene into commercial success.

Zack and Miri Make a Porno marks Smith’s second departure from his Askewniverse and his first response to Apatow’s audience.

Zack and Miri are grade school friends turned platonic roommates. Zack works at a non-copyright-infringing Starbucks while Miri works at the mall. The money they make is not enough, and as the bills keep piling up they sink into comic despair. The first act culminates at a high school reunion, which Miri wants to attend to seduce her high school crush, Bobby Long, played by Brandon Routh from Superman Returns. In a humorous twist, Bobby is in a gay relationship. Though Miri fails, the reunion does succeed in the classic function of highlighting Zack and Miri’s plight as they measure their own failures against their classmates’ success.

The two realize they have hit rock bottom when they contemplate their options in a dreary bar. This is when Zack gets the idea for a porno, an idea which-thanks to masterful Kevin Smith dialogue-appears altogether plausible.

From there, things snowball as Zack, the director, enlists coworker Delaney (Craig Robinson) to put up the front money for the film. This sparks a funny montage as they hire a cinematographer, hold casting calls and iron out a details such as the title of their film. In the end, they settle on “Star Whores” and prepare to shoot.

This is where the film takes a dip. Setbacks in production are unwarranted, chipping at the film’s credibility. It is unclear how big a priority Smith places on believability, but in all fairness, it should have been a larger one.

Starting out with the raunchiness as a given, Smith has the freedom of the entire film to develop the sentimental side to his tale. What is interesting here is that Zack and Miri do almost too good a job of being just friends. There is real chemistry between Elizabeth Banks as Miri and Seth Rogen as Zack, but it’s more a buddy picture than romantic. Until the big revelation, Miri is essentially one of the guys. Even so, it is obvious to any audience that she and Zack will end up together. The When Harry Met Sally rule-a guy and a girl can’t be just friends.

Zack and Miri Make a Porno is two steps forward, one step back for Smith. It’s his funniest film in years and sure to be a fan favorite, even as he begins to shed old habits. Smith makes some progress, but in the end retains enough of himself to probably keep this film from flourishing as much as he would like.