For reasons that escape her memory now, Shannon Murphy had missed the production of Rita Kalnejais’ “Babyteeth” when it first played Sydney’s Belvoir Street Theatre in 2012, an anomaly when the director had made a point of catching as many shows there as she could since the theater is where she started out. It helped when she would be recruited to direct the story of Milla, a young woman with cancer who falls into a whirlwind relationship with Moses, who also happens to be on a variety of medications for less noble reasons, much to the chagrin of her parents Henry and Anna, that she had no preconceived notions about the material from seeing it first on stage, instead reading Kalnejais’ script full of descriptions intended only for the actors to give a sense of the tone for any given scene.

The amusingly blunt titles for scenes such as “When Milla Met Moses on Platform 4” and “Milla Starts Chemo Again,” signaling the elephant in the room that the characters would constantly dance around, never made it into the play when it was performed, but Murphy puts them on blast in her feature debut, deploying the announcements of what’s to come in bright pastels as if to clear the air when the subject matter can seem so heavy, and throughout “Babyteeth,” an extraordinary film by any measure, the director is constantly locating the bits of joy that could easily been portrayed as a tragedy in another light, wringing out life from the premise of a family facing imminent death. Propelled by a truly dazzling turn from “Sharp Objects” standout Eliza Scanlen, the film starts at a train station and never loses steam as a chance encounter between Milla and Moses (Toby Wallace) gives both a reason to keep pressing on, with the latter attempting to pull away from a broken home while the former’s is breaking with her terminal diagnosis.

When Henry (Ben Mendelsohn) and Anna (Essie Davis) are at a loss for how engage with Milla, they uneasily start seeing the value in having Moses hang around the house, undoing any sense of civility they might’ve wanted to instill in their daughter, but providing the full-fledged teenage shenanigans that she might otherwise be deprived of, and it isn’t just the two young’uns who get to run wild, but Murphy, who so thoroughly gets inside of Milla’s experiences of firsts, for better or worse, and the shifting dynamics inside the family that your own neurons are rearranged to see the world anew. Shot with emotional precision by “Girl Asleep” cinematographer Andrew Commis and filled with bold musical choices throughout that contribute to its soul-stirring reach, “Babyteeth” introduces an incredible new filmmaker who has already kept things rolling with helming a pair of episodes from the recently concluded season of “Killing Eve” (including the pinnacle “Are You From Pinner?” visiting Villanelle’s family). Thankfully, she had the time recently to speak about what attracted her to adapting Kalnejais’ seriocomedy for the screen and keeping its daring sensibilities while building upon them.

How did this come about?

I just had an incredible experience when I read it where at the end, I was just beside myself with grief that I was no longer going to be able to spend any more time with these characters, so I thought the way to spend more time with them was to make the film. Rita’s writing is just so brilliant and her observation of human behavior is just so really unique and honest and her Australian sense of humor I thought was so clear. For somebody that doesn’t write, it’s often very difficult to find something that feels like my authentic voice, but that did, so that’s what made me jump on it.

So much of the tone seems to be conveyed through the color palette – if there’s any darkness, it’s always offset by something vibrant. Did it immediately come to mind as you were reading this?

I think I naturally have quite a colorful view of the world, possibly because I grew up in Hong Kong, which is a very neon city, and this felt like this is a really wonderful opportunity, considering it was a story about two young people falling in love, so [the color palette] came working with my costume designer and the set designer. We would talk about the different colors that we would play with, but also the idea that we wanted the film to feel timeless, so we’d often look at the colors in William Eggleston’s photography, which still feels so incredibly contemporary, but also is period. In the film we don’t really use phones or too much computer imagery because we wanted it to age well and also to not yet be stuck in a particular era and a lot of the costume colors came from that idea. Also these days, kids are wearing vintage clothing all the time and being really bold with their fashion choices. But then I knew that I wanted the world of the night out to be incredibly vibrant and the house, even though it’s this stifling atrium that Milla’s stuck in, at the same time, it still has warmth because there’s still so much love there from her parents despite the fact that they’re not parenting her in a way that she actually needs at this time in her life.

It’s an incredible house. How did you find it?

Our amazing producer found that house and when we walked in, we were like, “Oh my gosh, this is it.” We had to do a lot to it — we changed a lot of the colors in there and a lot of the furniture, but it was this beautiful mid-century home that had never been renovated and had glass the whole way through – you could see all the way out to the backyard, so for a story that’s very domestic, it didn’t feel claustrophobic in the shooting and the restrictions we had with walls.

For that first dinner table scene between the family with Moses there, I understand there wasn’t any improvisation as far as the script, but the camerawork seems quite intuitive to the characters’ emotions. Did your cinematographer Andrew Commis have a lot of leeway as far as being guided by the performances?

That’s interesting because that’s probably the scene that is the most shortlisted scene of all the scenes that we had because that’s really the first scene where you sink into the tone of the film, so it’s a very technically crafted scene and we knew we only had one day to shoot it. [laughs] That that was one of the first scenes we shot and we were looking at everybody’s lenses being a little bit different and slightly off-kilter at different moments, really owning the comedy in the story and nailing the tone, and it’s actually twice as long in the screenplay — there’s so much more dialogue that we had to lose because honestly, it’s just one of the most entertaining scenes even in its double length, and it just felt too out of balance with the rest of the scenes in the rest of the film once we cut it together. But every single shot there we knew beforehand exactly what we were getting whereas with a lot of the other scenes, we had shots we were definitely going to nail, but then it was more freeform.

An example of that, when Henry has the light bulb explode, we only had three takes with the time that we had to capture that and instead of doing what I wanted to do, which was shoot one way and then then other way, Andy just had to fling the camera around and catch both Toby’s lines and Henry’s lines and I had to mash it up in the edit. What was brilliant was I still said, I want that shot of Henry down at the bottom of the frame, looking like he’s lost and floating with all that aquatic sea life imagery floating above him and [I know] Andy will still nail those amazing moments even in those times of stressful panic on set.

There seems to be such a strong relationship between the camera and the characters in the film and I had heard you had taking acting courses in college since directing classes weren’t available. Does it inform your directing?

A hundred percent. I went to the University of Florida and did my undergraduate in performance because they didn’t have a directing degree. I did my honors in directing there and I took all my masters classes that I could get into, but I had to basically sneak in to learn more about directing, and I was kind of the worst actor in the sense that I hated learning lines. I’d always hide my script somewhere on the stage so I could just read it, and I would often be quite difficult with the directors because on some level, if they weren’t really talented, I felt I was better than them. [laughs] Which is so obnoxious, but I would call myself quite a difficult actor, to be honest.

It wasn’t what I wanted. I wanted to be behind the scenes, but what it did do is it allowed me to make sure that I never say anything to an actor that they can’t actually translate into their bodies or into their performance. That can often be a tricky thing for directors, not really understanding what language works for actors, so I would never change that I did this four-year course in performance because it helped me become an actor’s director.

Among many others, you have this amazing performance from Eliza Scanlen as Milla. What sold you on her for this?

It’s interesting because I think Milla’s the most challenging character to play because from the moment we meet her at that train station, that’s the only glimpse of who she really was before she met Moses. Her life starts catapulting into a new stratosphere and she also keeps redefining who she was at this age, with this illness, being a punk and rebelling against her parents, so she’s shape-shifting and it was a really challenging to still then feel like you knew and understood that when she’s still trying to work out who she is. There was also something about Milla [being] the adult in the film — she’s parenting her own parents and teaching them how to love her the way that she needs in this time and Eliza just had so much range and is so mature for her age that I knew that if we got together and we crafted Milla from scratch, we’d be able to come up with something really unique that also felt really grounded.

We would do things like she’d make me little music clips on Instagram, in her bedroom dancing to different pieces of music and she had to learn the violin and she had to shave her hair and build this relationship with Toby Wallace very quickly. She’s a very studious actress and throws everything into it — she writes journals in character and all of these things to really get into the mindset of Milla, so it was her incredible dedication. Rita had all these hints in the dialogue and in the story, but actually more than any of the other characters, she was a harder one to pin down in the text and [for Eliza and I] it was this wonderful opportunity to decide how Milla was going to be together.

There are so many great musical moments in the film, but specifically how did you come across the piece of music for the party scene?

That was a tUnE-yArDs track and Jess Moore, the music supervisor I’ve worked with for a long time, and I have had that song in mind for a while. When this film came around, we thought “Gosh, that’s the perfect piece for the night out because I didn’t want it to be like a party that we’d seen before.” That’s why I set it in an art school where there’s that vibe where you can have an interaction with a performance artist and really take it somewhere that maybe we haven’t seen before, and we’re experiencing what Milla is, which is entering into a new portal, a world she hasn’t seen just yet.

That song just felt right and we would play it on the day and that’s one take from the stairs leading them up into the party to the end of her interaction with the artist, so we had to do it quite a few times and I remember the crew members saying to me, “Wow, do you have the rights to this music because it’s really excellent?” And I think everyone in the room felt the power of what that was doing to all of us. It was helping Andy move in the space and Eliza and Shannon Dooley, the other actress, really connect in that moment. Music is so emotional and such a gut response when I’m picking those pieces, and it’s a bit of a world music piece and Milla, through Gidon [her music teacher, played by Eugene Gilfedder], has been opened up to those kind of sounds and she is really into that kind of music, so I thought that fit with what she’s attracted to.

The premiere of this film at Venice dovetailed with flying to the set of “Killing Eve.” What kind of moment is that like for you?

Venice was such a moving experience. My whole team was there with me and we’re this small film from Australia and suddenly we’re on the red carpet with so many of our heroes and just constantly looking around, going, “Oh my God, that’s Nicholas Hoult.” We were just taking it all in and so excited and appreciative that we were there. We knew how hard it was to get there and the hard work involved and it just felt like a really magical moment. Then yeah, to get on a plane and go straight into a job like “Killing Eve” was excellent. I was on such a high – I actually had an AirBNB scam happen to me and I lost a huge amount of money, which was actually great because that was a huge reality check. You think life is going really well and then you get smacked in the face. I think that’s how life works and it was kind of a perfect example of the ride and the tone of “Babyteeth” as well. Don’t get too used to things being wonderful because at any moment, they could come crashing down.

“Babyteeth” will be available in theaters, on demand and on digital on June 19th.