“Boundaries,” a road trip comedy starring Vera Farmiga and Christopher Plummer as a damaged daughter-father duo, premiered at the South By Southwest Film Festival last Monday night. The film, the majority of which takes place in a weed-filled Rolls Royce travelling from Seattle to Los Angeles, has as much heart as it does laughs.

The film, both written and directed by Shana Feste, the filmmaker behind “Country Strong,” “Endless Love” and “The Greatest,” has its quirky comedic elements: from Laura’s (Farmiga) penchant for picking up stray animals, to her son, Henry’s (Lewis MacDougall) talent for drawing naked pictures of authority figures. But behind all the humor is a realistic psychodrama, which is unsurprising given Feste’s proximity to her subject matter: Plummer plays a version of Feste’s own marijuana-dealing father.

Yahya Abdul-Mateen, known for his villainous roles in “The Get Down” and the upcoming “Aquaman,” plays a charming love interest for Farmiga. WSN recently sat down with Shana at SXSW, as well as actors McDougall and Abdul-Mateen to discuss breaking out of old patterns, balancing fiction and reality and working from a place of love and truth.

Washington Square News: ‘Boundaries’ is really different from your previous films. How do you approach doing something so different? Was this the type of film you always wanted to make?

Shana Feste: I definitely wanted to change it up. I didn’t want to make another melodrama or romance again. I wanted to make a comedy. And I think as artists, we always want to flex new muscles and do different genres, but the industry likes to tell you, ‘OK, no you’re actually the YA [Young Adult] person; you’re actually really good with romance; no, this is your lane.’ Thank god I’m a writer because I can write my own material. This was definitely a risk for me, but what I tried to do was make it as personal as possible. And by doing that, I think it made it more fun and easier for me to get out. Although it was terrifying also.

WSN: Lewis and Yahya, I feel like you can speak to this, too. Your roles in the film are quite different from your more recent work.

Lewis McDougall: I’ve been saying this: Henry’s a very unique guy; he’s a very unique character. And I’ve been fortunate enough to play a lot of different types of characters. That’s what makes it great — trying different things. Not only his personality or who he is, but I’ve also loved to do different accents, as well. It keep things fresh and keeps things new again — to try different things.

Yahya Abdul-Mateen: I think I joked last night that one of the challenges was trying not to foil the plot. You know what I’m saying? As the guy who’s always villains, I’m playing the guy who wants things to go right. I actually leaned over to my agent last night and said, ‘It’s gonna be really nice when I finally get to play a love interest in a story,’ because I think I’ve done six maybe seven films now — wow — and a couple television shows, and this is the closest I’ve been on any of that. But Serge was also a character with a really big heart. I could feel closer to myself on set and on screen. That was a lot of fun.

WSN: And Shana, you said the film is really personal for you. How you balance the fictional elements and the real life elements when you’re writing?

SF: I think everything I write, it comes from some sort of place of truth. Whether Henry is like my 12-year-old self that felt awkward and was misunderstood … every character I write from the same lens. So it’s tricky; it all sort of morphs together when you’re making the film. But I don’t think that’s a bad thing. I don’t think it gets in the way of anything. I think at its heart, I just wanted all of my actors to connect to something really truthful and not play the comedy and whatnot. We’re trying to connect with something real — real emotion

WSN: So Lewis’ character — that’s based on a younger version of you?

SF: Yeah, I think it’s like an amalgamation of what I want my son to be when he grows up, and what I was like — some of the insecurities that I felt. I don’t know. I was going to say how I mother, but maybe I’m a really overbearing mother if that’s the case. But I just fell in love with [Henry and Laura’s] bond, and I loved writing Lewis’ character because I love a boy that loves their mom. Maybe it’s a little bit of wish fulfillment writing.

WSN: I know you wrote this based on a road trip you took with your dad, but why did you choose ‘the road trip’ as the main arc of ‘Boundaries’?

SF: Well, I knew something had to change in [Laura and Jack’s] relationship. I knew that I did not want them to end where they started, and I knew it wasn’t gonna be a big change. I didn’t think they were ever going to like, embrace, and be like, ‘All is forgiven, let’s start afresh,’ but I knew there had to be a shift. What’s amazing about the road trip is that it’s about the journey, right? You meet so many characters along the way that illuminate your protagonist’s journey. So whether Christopher Lloyd was showing Laura of a really gentle side of her father that she had never seen before — even Bobby Cannavale gave Christopher Plummer a chance to really defend his daughter — that was something I think she really needed. Each character provided something that helped me get to a final moment of understanding, of being able to see your parent for who they really are.

WSN: Lewis and Yahya: other than the script, where did you draw inspiration for your roles?

LM: Well, I drew inspiration from Shana herself, just through having talked to her about the character, what he was going through and what he was feeling. I also took inspiration from my fellow cast members, through the way they talked to Henry, and just reacting to them.

YAM: This was a really, really easy character to step into, to love [and to] really care about this character. From then it was about, ‘How can I take the opportunity to share that?’ And he wasn’t a self-righteous character or anything, but I believe he was looking for someone to love also, and I think that’s what made him relatable. I think I just really drew on Shana’s vision. And from there, it was really about getting on board and figuring out that there’s ways to tell that efficiently.

WSN: You mentioned before the screening, Shana, that there’s a lot of moments where you might not believe that this really happened in your life, but it did.

SF: Yeah, there’s so much truth. I mean it was just all aligned just verbatim. My father’s been in prison for trafficking marijuana. I grew up with a lot of weed around me, and my father was in and out of my life, just kind of like the story. So there was a lot of truth to that. And his humor, you know, he was such a funny, funny man, so I hope I captured some of his rascal humor.

‘Boundaries,’ which will be distributed by Sony Pictures Classics, opens in theaters on June 22.

A version of this article appeared in the Monday, March 19 print edition. Email Natalie Whalen at [email protected].