We present a procedural technique for the synthesis of detailed and controllable terrains. We generate terrain based on a sparse curve network representation, where interconnected curves are distributed in the plane and can be procedurally assigned height. The user controls the placement and elevation of peaks. We employ path planning to procedurally generate irregular curves around peaks. Optionally, the user can specify base signals for the curves. Then we assign height to curves using biased random walks with controlled probability distributions, a process which we show produces signals
with distinct shapes. The structure of a curve network partitions space into individual patches. We interpolate patch heights using mean value coordinates, after which we have a complete terrain heightfield.