Two decades ago, the University of Maryland began to see a run of especially talented cartoonists come through campus, including eventual “Boondocks” creator Aaron McGruder and top comic artist Frank Cho. A more gradual success story was JEFF KINNEY, who — after his stint at the school’s Diamondback newspaper — worked as a designer and game developer for years as he continued to craft his comic style.

Then came 2007 — Kinney’s breakout year.

It was in 2007 that Kinney — while at the online educational company Pearson — helped develop, a virtual world for children. The site launched that year and exploded; it now calls itself the most popular kids' site on the web, with 130 million fans.

It was also in 2007 that Kinney — having been discovered at a New York comics convention — debuted his book, "Diary of a Wimpy Kid." It likewise exploded. The "Wimpy Kid" series has sold in the millions, spawned book tours and — as most any fifth-grader can tell you — catapulted Kinney to rock-god popularity among the playground set.

Today, Kinney sees the opening of his sequel feature film, “Diary of a Wimpy Kid: Rodrick Rules,” which is expected to stoutly challenge for the top spot (with “Sucker Punch”) at this weekend’s box office.

Comic Riffs caught up with Kinney this week to discuss the joys and pressures of producing a Hollywood sequel:

MICHAEL CAVNA: So Jeff, how did you approach the “Wimpy Kid” film sequel differently from the first go-round? Was it easier this time — obviously your core casting was already in place — or did you feel more pressure?

JEFF KINNEY: I think I approached the second film with a more relaxed state of mind. Casting was such a big part of the first film, and we knew going into the second that we were well-armed. I remember meeting up with the kids in the cast in Vancouver, when we gathered for the table read. I looked at them all standing together and thought, “Wow, this looks like an iconic group of kids.” We all felt pressure to deliver the goods, but we had a good script that improved during filming.

MC: Chloe (Grace) Moretz of course had a breakout role [as Hit-Girl] since you first cast her. Can you speak to what it was like working with these talented, more experienced kids this time around? And did the cast have even greater chemistry and camaraderie?

JK: When we got together in Vancouver in August, it felt like everyone was coming back to summer camp. In a way, it felt too good to be true. We had almost the whole crew back as well, and everyone was thrilled to be reuniting. I feel like we were planning to create a trilogy of films from the outset, so it felt great that we had earned the right to continue the story. The actors are very fond of each other, and I think that comes across on the screen.

MC: Creatively, how did you decide to focus on Rodrick in the sequel — did that seem like a natural choice [given the book series sequence], or did you kick around many options for this project?

JK: I think that focusing on Rodrick and the family dynamic was the next logical step. The first film is about middle school, but the second film is about the family. We more or less stuck with the blueprint from the second book, which is a story about a sibling rivalry.

MC: What do you find most satisfying about filmmaking, as opposed to Poptropica and writing the books?

JK: I think the most satisfying part about filmmaking is seeing a production in full bloom. When I write, I write in isolation. It’s very exciting to see, for example, a roller skating rink that was built from scratch just for a single scene in the movie. It’s exciting to think that it sprang into existence from an idea. What’s also satisfying is seeing how people’s lives have changed because of the films. Zachary Gordon and Robert Capron, who play Greg and Rowley, have certainly had the course of their lives altered by these films. Even people who have very small parts have gotten to be a part of something really exciting and enriching.

MC: Any real surprises with this production — anything that blindsided you, shocked you or was a true learning experience with this, your second stint in the exec-producer’s chair?

JK: What most surprised me on this film was the performances of Rachael Harris and Steve Zahn. I can’t believe we landed who I consider to be two of the best comic actors around. I think that Rachael and Steve make so much out of every moment they’re on screen.

MC: You’ve got some very talented lead actors — kids who are both comically gifted and naturalistic. Can you speak to what talents of theirs you’ve especially come to prize and appreciate?

JK: Both Robert and Zach are natural comic talents. Zach has a gift for making you root for a character who doesn’t always make the best choices. Robert’s talent is a mix of charisma and expressiveness. My favorite scenes are when the two actors are together in a scene, alone. There’s a sweetness to their friendship that’s very believable. Devon Bostick was a terrific find as Rodrick. He didn’t have a huge role in the first film, but he had to carry big parts of the second. My hat goes off to the casting director, who saw the potential in Devon as a comic actor with great range.

MC: If “Wimpy Kid” continues its cinematic success with the sequel, you’ve got a full-on film series on your hands — if you want it. Any plans yet as to shooting a third “Wimpy” before these kid actors outgrow the roles -- and would you consider letting them age onscreen, a la “Harry Potter”?

JK: We’re laying the groundwork for a third film now. Of course, you never know if you’re going to get the green light, but if we do, we’ll be ready to go. Everyone involved with these films hopes to be able to tell as many stories as possible. What’s exciting is that these kids are actually the age of their characters... in fact, both Robert and Zach missed their first days of real-life middle school to shoot the first film. But the inconvenient thing about middle-school kids is that they tend to change quickly. We’re all aware of this and there is an urgency to film while the kids are the age of their characters.

MC: What”s next for you — from Poptropica to the series to any other projects? And might we ever see a film from you that’s not “Wimpy Kid” — perhaps animation or something else related to Poptropica?

JK: I’m keeping my day job, because Poptropica is something that really energizes me. I’d love to create a TV series or write a film that’s not in the Wimpy universe, but I know it will be difficult to create something from scratch. But I love creating good comedy for kids, so I hope to have another successful venture in the future!

The 'Riffs Interview: Artist JOHN ROMITA JR. talks family business, Big Daddies & big-screen sequels