Procedural Noise

Fractal Brownian Motion

producing smooth motion that appears random, yet much less noisy than purely random:

Sum your noise function at different amplitudes, increasing the function’s frequency as amplitude decreases

Bilinear interpolation

Worley

Grad-based

Optimizing

Min distance of neighbor 9 point

Perlin Noise

Grad-based

Not recommend Bilinear interpolation: too clear line between cells