2D Perlin noise maps x,y coordinates to smooth organic texture fields

One-dimensional Perlin noise produces a smooth sequence along a single axis. Passing two arguments — noise(xnoise, ynoise) — creates a 2D noise field: a plane where each coordinate maps to a smooth value between 0 and 1, with neighboring positions having similar values. To traverse the field, use nested loops over x and y, incrementing separate noise seeds for each axis. Reset the x seed at the start of each row (like a typewriter carriage return) to correctly tile the 2D field. The returned value can drive any visual property: alpha, size, rotation, color, or 3D displacement. Animating the field by incrementing the base seed each frame creates the illusion of a drifting texture — the camera scrolls over the noise plane.

Examples

Noise as alpha: int alph = int(noise(xnoise, ynoise) * 255); stroke(0, alph); point(x, y); produces a soft cloud-like texture. Noise as rotation: draw a line rotated by noise(xnoise, ynoise) * radians(360) at each grid point — produces a flow-field of oriented strokes.

Assessment

Describe the visual difference between a noise field traversed with increments of 0.01 versus 0.1, and explain why the increment size controls the scale of the texture features.