The noise field is treated as a height map. We draw the level sets — the curves where the noise value crosses a threshold (0.1, 0.2, 0.3…). These are called isolines.

Computed via marching squares: each cell of a fine grid is checked for threshold crossings, and crossing points on cell edges are connected with line segments.

Multiple noise octaves (fBm) are layered at increasing frequencies and decreasing amplitudes — each adds finer terrain detail. More octaves = more crinkled, fractal contours.

Key variables: noiseScale (broad hills vs. crinkled terrain), levels (number of contour bands), octaves (1 = smooth, 4 = fractal detail).