Animal Well smoke simulation made me think about a guy that died in 1783

12/04/2026, 11:19

Games, Programming

No spoilers of Animal Well here.

Animal Well has JUICE! But not the type of juice we're used to in games that focus on it. I don't even think the game focuses on having juice like those games do. The juice is present in places that "normal developers" usually wouldn’t think of adding, or wouldn’t have the technical knowledge to implement.

I'm talking about the water simulation, the vegetation simulation with collisions that bend when you walk over them, the "toys" simulations. And of course, my favorite: the smoke simulations.

By the way, if you don't know what a game with JUICE is: it's basically a game that moves/feels/sounds/acts/plays... good. It just feels good to move, click, or hear things. Okay, it's hard to explain. Check these examples below, created by PolyCube.

First-person shooter with juice:

First-person horror game with juice:

I never watch people play games that I know I want to play someday. And that was no different with Animal Well. The game was released in May 2024, and I only played it in March 2026, so I had a really good experience.

But in 2025, Wookash Podcast released an interview with Billy Basso, the developer who made the game by himself. I was so eager to listen that I watched it even before playing the game.

For context, the Wookash Podcast focuses on interviews with actual software developers,the people doing low-level work. Since I'm fascinated by that, especially in game development architecture, I had to listen. At the time, the only thing I had seen of Animal Well was the gameplay trailer, and I knew the game size was around 50MB. That immediately suggested a custom-built engine. That’s what caught my interest. Watching the trailer, I kept thinking about the dynamic lighting, the simulations, and how shadows interacted with what looked like 2D assets but behaved almost like 3D. I assumed it might be using normal maps on pixel art,which is not something you see every day. So yeah, I really wanted to hear how he made it.

Later, Lost in Cult announced a design works book for Animal Well, and this is one of the images showing the normal maps.

After I played the game, I started searching for sources where Billy Basso talked about the smoke simulation, and he confirmed he used Eulerian fluid simulation.

After that, I spent some time reading about Eulerian fluids to better understand what was going on.

Here are some resources I used:

I'm not pretending I understand the math. I'm just curious about the process and the history behind it. I ended up reading about Leonhard Euler,the guy who created the equations in 1755. That’s fascinating to me. A formula created in 1755 is still being used in video games today. Do you think he could have imagined that? Obviously not. Photography didn’t even exist yet. Benjamin Franklin had just done his lightning experiment a few years before. It’s just incredible to think about how far we've come.

To finish, I just wanted to save here my attempt at an Eulerian simulation. I obviously followed a YouTube tutorial line by line,I wouldn’t be able to do this on my own. I used C++ with Raylib to render it. Still, it was a great exercise to at least get a feel for how it works. Thanks to BigCodeNeck for the video.

And here are the results:

The black-and-white version is a simple smoke simulation, and the other one is the same simulation with color to better visualize the grid and behavior.

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