“Elemental,” the latest cartoon movie from Pixar, is based on a story that director Peter Sohn has close ties to. In the beginning, we see a family arrive on the made-up port of Elemental City. This is a lot like how Sohn’s-parents moved-from Korea-to-New York.

Fire, water, land, and air are given life in the story by making them into people who live in Elemental City. When Ember (Leah Lewis), a young woman with a lot of fire, meets Wade (Mamoudou Athie), a water being who goes with the flow, they find that, despite their differences, they have a lot in common. As Ember and Wade fall in love, she has to decide if she wants to be with Wade or if she wants to run the family business like her parents did. Ember’s struggles came from Sohn’s own life as the son of first-generation immigrants. They also came from the lives of many of the animators and writers who worked behind the scenes.

Below, Sohn talks to Variety about why it took seven years to make “Elemental” and what it means to have his story become part of cartoon history.

The first episode of “Elemental” came out the other night. What was that like?

It was a very sad event. People felt a lot of joy. I’ve never done something as personal as this before. So, this was the first time I shared a part of myself with a group of people. Even though it’s scary, it’s not just my story. It’s the people with whom you work. They told their stories, and many other people’s stories were used to make that movie.

I lost my dad early on, and then I lost my mum at the end. So there was an emotional tie to just finishing it and bringing it to an end.

The world of “Elemental” is full of life and colour. How did you and the artists work together to build the city?

It took seven years to make this happen. The players had no way to get anywhere. In the past, the company has made characters that are plastic or metal cars or humans with a subsurface scattering in the skin, but there was no way to make a character that was just an effect, and it was scary because everyone doubted they could do it. So, getting this character, Ember, to blink was a hard process.

When we first showed Ember’s face and she blinked and smiled, it was such a big deal and a big step forward. It was hard to make something that was a gas and could be linked to. Her first drawings were really scary because she looked like a Weta FX character from “Lord of the Rings.”

What were some of the design difficulties that came with giving fire and water soul?

I drew these fire figures as if they were superheroes. They were getting rid of all of their things. I drew these two hands holding water and fire. Even though they didn’t touch, the heat from her hand would bring the water to a boil, which would cool the water down. When you were about to touch someone for the first time, you got goose bumps. Or, when she gets mad, she turns into this fire and bursts. She can get angry even if she doesn’t say anything.

We were making a link between the different feelings you might have in a relationship, and that was our big idea that people can relate to.

The beginning of the movie really celebrates immigration. What does it mean to you to be able to enjoy and immortalise your parents’ journey?

I hadn’t looked at it that way before. I was a very ignorant and rude kid to my parents because I didn’t know how hard it is to grow up in that world. When my parents told me about how they lived through the Korean War or how they had nothing, I’d say, “OK, can I play video games now?” I was a kid like that. As I got older, I began to understand. How did they do it if they didn’t speak the language? When I got married and had kids, I realised how much I valued what they had done for me. So, the point of that beginning was to show how hard it was for them to enter this new world as outsiders.

Since the characters are based on the elements, do you like science a lot?

Even though I like science, I wasn’t very good at it. I think that’s why I liked cartoons so much: when you turned the pages, something magical could happen. It was different for me to look at the periodic table, break down the atomic number, and see how that related to the elements. This idea came from making figures out of the buildings drawn on top of this periodic table.

What do you want people to learn from “Elemental,” whether they watch it in the theatre or at home on Disney+?

It’s a very honest movie. I never thought I’d have such a close connection to something. It’s about how we should thank our parents. I got lost while making this, but every time I did, I went back to the north star of how much I appreciated them. It wasn’t easy to make that sacrifice. It’s also about getting people from different cultures to understand each other better.