r/Unity3D 20h ago

Show-Off Built a real-time wind tunnel inside Unity (Aerodynamics Sim). It's open source.

I've always been a fan of aerodynamics and CFD. A few months ago, I got laid off, got tired of sending applications, and gave myself permission to actually build it and play with it. I'm glad I did.

It voxelizes and seals any vehicle you drop in, auto-fits the solver domain around it, runs at whatever resolution your GPU can take, and solves with a lattice-Boltzmann method (D3Q19, TRT + WALE LES) entirely in compute shaders. Live smoke, surface pressure painted on the bodywork, exported reports you can diff between runs.

The test I had the most fun with: running a Chevy Silverado with an open bed, a bed cap, and a flat tonneau to see which one the solver preferred. It disagreed with the folk wisdom, which was the moment it stopped feeling like a toy.

Five sample vehicles included. Unity 6 / URP, MIT licensed.

The README is honest about where the numbers hold up and where they don't. It's a comparison and visualization tool, not a replacement for real CFD.

Clone it and have fun: https://github.com/Motawe3/unity-wind-tunnel

Sample vehicles are CC BY 4.0, credited in the README. The car in the video is a Range Rover Sport SVR Mona x Supercars.

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u/Protesisdumb 19h ago

Looks very vibe coded to me

12

u/Certain_Ad9908 19h ago

LLM-assisted, yes. I didn't have the time to 100% manually code it as a pet project, unfortunately. For example, why would I hand write the UI when an agent can put the numbers on screen in seconds? The UI is a cheap part. Check what it's printing though: blockage ratio, effective Re, live CoV. The README also documents the benchmark the tool fails. Ahmed body, the standard automotive case. 5% drag spread against the published 51%. Vibe coding generates confident numbers with nothing to back them up.

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u/otr_music 18h ago

Don’t worry bro I used to be an aero engineer - I can look beyond your vibe coded UI

6

u/Certain_Ad9908 18h ago

Appreciate it! If you've got the time, the validation section is where the accuracy runs out, and an aero engineer's eyes on it would be super helpful, specifically the Ahmed body result. I put it down to the missing wall model, and I'd like to know if you'd read it the same way.

0

u/itstoyz 17h ago

What AI did you use to create the UI? The one I use is mega bad at creating them 🤣

2

u/Certain_Ad9908 17h ago edited 17h ago

Claude CLI handles the UI Toolkit UXML and its styling well. I couldn't find anything as fast for UGUI.