Real-time Terrain Enhancement with Controlled Procedural Patterns

Assisting the authoring of virtual terrains is a perennial challenge in the creation of convincing synthetic landscapes. Particularly, there is a need for augmenting artist-controlled low-resolution models with consistent relief details. We present a structured noise that procedurally enhances terrains in real time by adding spatially varying erosion patterns. The patterns can be cascaded, i.e. narrow ones are nested into large ones. Our model builds upon the Phasor noise, which we adapt to the specific characteristics of terrains (water flow, slope orientation).Relief details correspond to the underlying terrain characteristics and align with the slope to preserve the coherence of generated landforms. Moreover, our model allows for artist control, providing a palette of control maps, and can be efficiently implemented in graphics hardware, thus allowing for real-time synthesis and rendering, therefore permitting effective and intuitive authoring. Our procedural model enhances a low-resolution input terrain with spatially varying erosion patterns. (a) Input terrain h. (b) Large patterns r(1) generated consistently with the terrain. (c) Narrow patterns r(2) added in cascade, based on the same formulation. (d) A fractional Brownian motion improves the appearance of crest lines.image