Minecraft wiki entry for Procedural_animated_texture_generation, associated text: Fluid textures are generated via 3-layer non-deterministic cellular automata, which modify the RGB and alpha values of the texture accordingly,[2] along with shifting of the texture to emulate flowing. Each layer is represented as an array of floats, each with 256 elements, corresponding to the 256 (16x16) texture pixels within the block.[2]