Table mountains by virtual erosion

Abstract

We present an ef cient algorithm for visual modeling table mountains (mesas) using erosion simulation. The method uses techniques from Computer Graphics to closely model the phenomenon, without relying on physically correct modeling. Our main goal is to devise an ef cient algorithm that is geologically inspired and simulates visually plausible results in a reasonable time with certain user control over the process. The algorithm models a terrain as composed of two different materials, the hard one (rock) and the soft one (sand). The hard material is exposed to moisture and thermal changes that erode the side parts (the rimrock) of the table mountain. The eroded parts fall and change into the soft material. This material is subject of a different type of erosion. The soft material moves as sand or gravel with high inner friction. It moves slowly trying to reach an equilibrium and forms characteristic hillside of table mountains. We simulate this slow motion of soft material by a diffusion algorithm. The algorithm presented here achieves visually plausible results in reasonable time. The results are in tune with mountains observed in nature, and are comparable to the existing terrain modeling and displaying techniques.