Three.js background animation

Hello everybody, hope you are doing well.

Please check once this website: Karma
Here what I’m interested is background animation looks similar with smoke effect,.
I know that they use three.js and GSAP for background animation there.
I have no idea how to do it.
Please let me know if you have idea.


No need for GSAP there - it’s a simple 2D fluid simulation (a simple example & code, and a way more detailed explanation.)