I think it's technically Simplex noise, but yes also developed by Perlin.
Author here, yes you are correct that it's Simplex noise. I also use a method of domain warping, I used this article as reference https://iquilezles.org/articles/warp/
Author here, yes you are correct that it's Simplex noise. I also use a method of domain warping, I used this article as reference https://iquilezles.org/articles/warp/