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Show HN: Vanilla JavaScript refinery simulator built to explain job to my kids

Hi HN, I’m a chemical engineer and I manage logistics at a refinery down in Texas. Whenever I try to explain downstream operations to people outside the industry (including my kids), I usually get blank stares. I wanted to build something that visualizes the concepts and chemistry of a plant without completely dumbing down the science, so I put together this 5-minute browser game.Here's a simple runthrough: https://www.youtube.com/watch?v=is-moBz6upU. I pushed to get through a full product pathway to show the V-804 replay.I am not a software developer by trade, so I relied heavily on LLMs (Claude, Copilot, Gemini) to help write the code. What started as a simple concept turned into a 9,000-line single-page app built with vanilla HTML, CSS, and JavaScript. I used Matter.js for the 2D physics minigames.A few technical takeaways from building this as a non-dev: * Managing the LLM workflow: Once the script.js file got large, letting the models output full file rewrites was a disaster (truncations, hallucinations, invisible curly-quote replacements that broke the JS). I started forcing them to act like patch files, strictly outputting "Find this exact block" and "Replace with this exact block." This was the only way to maintain improvements without breaking existing logic.* Mapping physics to CSS: I wanted the minigames to visually sit inside circular CSS containers (border-radius: 50%). Matter.js doesn't natively care about your CSS. Getting the rigid body physics to respect a dynamic, responsive DOM boundary across different screen sizes required running an elliptical boundary equation (dx * dx) / (rx * rx) + (dy * dy) / (ry * ry) > 1 on every single frame. Maybe this was overkill to try to handle the resizing between phones and PCs.* Mobile browser events: Forcing iOS Safari to ignore its default behaviors (double-tap zoom, swipe-to-scroll) while still allowing the user to tap and drag Matter.js objects required a ridiculous amount of custom event listener management and CSS (touch-action: manipulation; user-select: none;). I also learned that these actions very easily kill the mouse scroll making it very frustrating for PC users. I am hoping I hit a good middle ground.* State management: Since I didn't use React or any frameworks, I had to rely on a global state object. Because the game jumps between different phases/minigames, I ran into massive memory leaks from old setInterval loops and Matter.js bodies stacking up. I had to build strict teardown functions to wipe the slate clean on every map transition.The game walks through electrostatic desalting, fractional distillation, hydrotreating, catalytic cracking, and gasoline blending (hitting specific Octane and RVP specs).It’s completely free, runs client-side, and has zero ads or sign-ups. I'd appreciate any feedback on the mechanics, or let me know if you manage to break the physics engine. Happy to answer any questions about the chemical engineering side of things as well.For some reason the URL box is not getting recognized, maybe someone can help me feel less dumb there too. https://fuelingcuriosity.com/game

58 points by fuelingcurious - 24 comments

24 Comments

usui [3 hidden]5 mins ago
I just want to say that despite the AI negativity in other places, this highlights the positive aspect of it. I'm sure this could have been done without it, but I'm glad OP could get it out faster for a low-risk use case, shared it with us, and in the process taught a little bit of refining to others. It's a fun minigame.
fuelingcurious [3 hidden]5 mins ago
Hello y’all as the post says, certainly a novice stepping into y’all’s space, but I am passionate that we can use the newest form of coding to allow us to change the way we teach. I think it’s a different way to use AI to teach, not having it explicitly do the teaching, but a way to extract context from different backgrounds into more fun learning tools.
idiotsecant [3 hidden]5 mins ago
This is a great example of the kind of 'good enough' software that LLMs enable. Before LLMs existed you'd either hire someone to do this an exorbitant cost or you'd pick up a second full time job learning the nessessary skills.

This software doesn't need to be massive scaled, hyperperformant, and absolutely bug free. It just needs to do its job well enough, which it does.

I am also a (non-software) engineer and although I can write software (poorly) I have also used these tools to do some things that previously just wouldn't have gotten done.

We still need people to do Serious Software but for millions of little applications like this LLMs are a game changer.

why_only_15 [3 hidden]5 mins ago
Very cool stuff! Thank you for making.
insin [3 hidden]5 mins ago
Phase 1b: The Desalter doesn't show anything on the grid in Firefox (v148.0.2), so you automatically lose.
fuelingcurious [3 hidden]5 mins ago
Ah interesting, I have playtested on safari, chrome, and edge. I’ll have to look into what’s unique there. Thank you!
joeframbach [3 hidden]5 mins ago
I figured out why it wouldn't work on my machine:

    @media (prefers-reduced-motion: reduce) {
        *, *::before, *::after {
            animation-duration: 0.01ms !important;
            animation-iteration-count: 1 !important;
            transition-duration: 0.01ms !important;
        }
    }
With reduced-motion enabled (which is basically required in Tahoe :eyeroll:), animations complete immediately and there is no chance to click the salt/water.
cameron_b [3 hidden]5 mins ago
Up-to-date Firefox on Linux allowed me to complete certification of a shipment of Jet fuel, no trouble all the way through.

Great concept and execution.

fuelingcurious [3 hidden]5 mins ago
Hurray! Thank you for the update note. I was going to get after it tonight after I put the kids to bed otherwise.
superxpro12 [3 hidden]5 mins ago
On Win11 Firefox latest (148.0.2), I still cant see them :\

You owe me nothing! I just wanted to let you know!

fuelingcurious [3 hidden]5 mins ago
If you open the Firefox inspection window, right-click any element on a webpage and select Inspect. Alternatively, use the keyboard shortcut Ctrl+Shift+C (Windows/Linux) or Cmd+Option+C (Mac). You can also access it via the menu button (three horizontal lines) -> More Tools -> Web Developer Tools.

Does it show any errors?

ecshafer [3 hidden]5 mins ago
Great little education game. Sulpher particles move really fast, might be worth slowing them down 20%. I was basically random clicking to get them.
fuelingcurious [3 hidden]5 mins ago
Fair point, I have a rebound energy and terminal velocity set, still lower the top speed! Thanks for the feedback.
zbuttram [3 hidden]5 mins ago
Great to see a spiritual successor to SimRefinery[1] after all these years!

[1] https://en.wikipedia.org/wiki/SimRefinery

fuelingcurious [3 hidden]5 mins ago
I’ll take the compliment! My goal was to keep each unit to simple tap and drag play dynamics. If there’s another curiosity, mechanical, electrical, another unit, I can add it to the development plans. It’s fun for our family!
Tacite [3 hidden]5 mins ago
It's very good and you can be proud. Your kids should be too!
fuelingcurious [3 hidden]5 mins ago
Thank you! They call themselves my play testers and ask to see if I have added anything new almost daily for the last week or so. I have a bonus level for the SRU I’m trying to perfect.
TheGamerUncle [3 hidden]5 mins ago
Hi sorry do you have the code for this I have been delaying to work on something like this but would love to use this as boilerplate.
fuelingcurious [3 hidden]5 mins ago
Hello! Thank you for the vote of confidence! I deliberately left the client-side JavaScript un-obfuscated (AI showed me how to do it, but then I undid it for posting here). A colleague of mine started talking about selling it as a training tool, but ha I don’t know if that is in the cards. If you send me an email, we can talk about helping you get a head start!
bcze56bbn854 [3 hidden]5 mins ago
Thanks I really liked it and it taught me a lot
fuelingcurious [3 hidden]5 mins ago
Great! Anything uniquely unexpected?
sealthedeal [3 hidden]5 mins ago
This is awesome
fuelingcurious [3 hidden]5 mins ago
Love it! Hopefully you learned something too!
bcze56bbn854 [3 hidden]5 mins ago
Great jobb!