River Networks for Instant Procedural Planets

Realistic terrain models are required in many applications, especially in computer games. Commonly, procedural models are applied to generate the corresponding models and let users experience a wide variety of new environments. Existing algorithms generate landscapes immediately with view-dependent resolution and without preprocessing. Unfortunately, landscapes generated by such algorithms lack river networks and therefore appear unnatural. Algorithms that integrate realistic river networks are computationally expensive and cannot be used to generate a locally adaptive high resolution landscape during a fly-through. In this paper, we propose a novel algorithm to generate realistic river networks. Our procedural algorithm creates complete planets and landscapes with realistic river networks within seconds. It starts with a coarse base geometry of a planet without further preprocessing and user intervention. By exploiting current graphics hardware, the proposed algorithm is able to generate adaptively refined landscape geometry during fly-throughs.