You don't need to be an engineering whiz to appreciate the talent that went into the gorgeous reflection of sunlight on water in Walt Disney Animation Studios' new computer-animated movie Moana, featuring Dwayne Johnson as the demigod Maui and newcomer Auli'i Cravalho as Moana.

Karl Li, a graduate of North Penn High School and the University of Pennsylvania, worked on the movie as a Disney software engineer, helping to perfect the appearance of water, sunlight, and feathers, among other tricky feats.

He spoke with us last week about working behind the scenes at Disney, how he got there from here, and why his parents are OK with the fact that their Ivy League-educated son is neither a doctor nor a lawyer.

This is your first movie credit with Walt Disney Animation Studios. What exactly is your film credit, and what does it mean?

I'm credited as a software engineer out of our technology rendering department. What that means is that I worked on our in-house rendering software that we created the movie with. If you're not familiar with what rendering software is, it's basically the software that simulates all of the lighting and all of the surface color and surface detail and that kind of stuff.

I'm actually going to be back in Philadelphia for Thanksgiving week and we're going to go see the movie on opening day as a family. And we're going to stay through the credits.

What got you interested in working in animation?

I know this sounds kind of clichéd, but it was watching Disney films growing up. My brother and I, we were always into just running around with a video camera or trying to animate stuff inside of Flash. ... And then, after that, kind of going to school and doing computer science with a focus on animation technology -- it seemed like a natural succession.

What animated movies did you like growing up?

You know, I'm a '90s baby, so I grew up watching the great Disney renaissance films and, later on, the Pixar films in the 2000s. I think  a lot of the Disney films from the 2000s weren't as widely recognized as the Pixar films from that same period, but I actually really like those, too. I grew up watching Atlantis and Treasure Planet and Lilo & Stitch on repeat, and wore out VHS tapes.

Is your brother excited about the movie? Is he still interested in animation, too?

Oh, yeah, he actually studies the same things that I studied in college. ... We both ended up going to Penn.

You went to Penn — do your parents wish you'd pursued something like law or medicine?

When I was in college, I actually did this short detour through business school, because I didn't realize that making animated movies was actually a real job that people had. And then I discovered that Penn had this digital media and design program, and Disney actually had this huge animation studio with all these incredible people, so I quickly bailed out of business school.

Both of them are really proud and they've been super, super supportive this entire time. Like, my dad insists on going to see every single Disney film, even if it's not necessarily from Disney Animation. If it says "Disney" on it, he goes.

All of my family friends, a lot of them went on to become lawyers or doctors or bankers or whatever, and that was kind of just the norm inside of the circle of family friends that we had. So my mom gets a big kick out of, you know, everybody else's kid is doing something relatively normal and then her kid is working at Disney Animation. She thinks it's awesome.

What kinds of classes did you take to catch Disney's attention?

I think the big one at Penn is, there's this computer graphics course that's taught by this professor, Norm Badler. That course introduced me to a lot of stuff and acted as a launchpad for me to go out and learn a lot of stuff on my own and build a bunch of products. Those are the kinds of things that eventually, I guess, caught Disney's attention.

I spent a lot of time when I was in college kind of not really paying attention in my other classes. Like, I spent a lot of time in college building my own sort of homebrew rendering software, and I had this blog that I posted all of my progress on and all of my thoughts.

That actually led me to getting internships at Pixar and at DreamWorks, where I worked with rendering teams. And then one day, Disney just called kind of out of the blue. ... I don't fully understand how I wound up here, but I'm not going to complain.

Is working at Disney Studios how you imagined it to be?

I never really thought about what it would be like to work here when I was little. Like, part of me just didn't connect that, 'Oh, there's these movies, and there's an army of hundreds of artists and engineers that actually make them.'

Everybody knows that Disney has huge numbers of just the most incredible artists in the world, but I guess what I didn't realize before was that there's also a large number of really good engineers, and that the engineers and the artists work really closely.

Do any of the scenes you worked on stand out for you?

Our team doesn't necesssarily work on individual scenes. We kind of work on the underlying software. But we do end up helping out the artists on scenes that are particularly troublesome.

There's this sequence in the middle of the movie where Moana flashes back to her ancestors' voyage across the ocean, and Lin-Manuel Miranda is singing this amazing song, and a lot of those shots were extremely difficult to push through. They were some of the earliest shots that we put into production, and we were still ironing out the kinks.

We spent so much time getting the software to render the water correctly and to have the proper blue color, and to get the spray to look like spray, and to get the skin to look wet.

I want to know -- did you get to meet Dwayne Johnson?

No, I did not. But I've heard that he's pretty cool. I heard that meeting him is kind of like meeting Maui, but in real life.

After Moana, what's next for you?

Right now, I'm working on our next two films, Wreck-It Ralph 2 and Gigantic. Every movie has its own set of challenges and set of problems that we have to solve, and every movie kind of has its own look that we need to hit, so there's always stuff for our team to be working on.