Synthetic Modeling Method for Large Scale Terrain Based on Hydrology

Generating large scale terrains that conform to the morphology of real scenes is a great challenge for terrain modeling, as simulating complex geometric details is time-consuming and the realistic geographical features are hard to be controlled. In this paper, we propose an efficient modeling method for large scale terrain visualization based on hydrology. To simulate real geographic features, we introduce the hydrology-based Tokunaga river network to guide the terrain generation, and propose a production rule set of river network using procedural modeling. The distribution and structure of river network can be adjusted by user interactions. Ridges are extracted based on river network to provide more skeleton features, and the enrichment method of skeleton features is presented to maintain the morphology of valleys and ridges. Based on the enriched features, diffusion equation is exploited to compute the full elevation field, which can achieve the nature transitions of the regions between skeleton features. Large scale terrain with real morphological features can be generated online through the parallel implementation of diffusion equation. According to user requirements, the augmented virtual terrain can be obtained by blending the selected real terrain with the synthesis terrain seamlessly. The experiments are conducted on digital elevation model, and the results show that the proposed methods can generate large scale terrains that conform to the morphology of real terrain and can well simulate various natural scenes.