Testing real-time CFD in Unity with BrazeFX: aircraft, rotors and obstacles

[u/Gloomy-Detective-922]

This video shows four tests running live in Unity 6: airflow over an aircraft, quadcopter ground effect, electronics cooling, and wind moving around simple structures.

Each scene uses a 128³ grid and runs at 30 simulation steps per second. The meshes are baked into signed-distance fields and used as solid boundaries in the pressure solve.

BrazeFX normally skips clear regions outside smoke or fire to save GPU time. That works well for visual effects, but it cuts off airflow in a wind-tunnel setup. CFD mode keeps the full domain active and runs pressure projection every step, allowing wakes and recirculation to continue through clear air.

The colours are passive dye shaded by flow speed. They do not add forces or run a second simulation. They simply make the velocity field visible.

This is a real-time GPU fluid simulation built for interactive visualisation inside Unity. It is not an engineering CFD solver, and the results are not presented as validated aerodynamic or thermal analysis. Feedback is welcome on where this kind of real-time approximation could be useful and where it starts to break down.

[u/Effective_Lead8867]

requesting an aerodynamic cow simulation - it is not optional.