3D Isocontours Real-time Generation and Visualization of 3D Stepped Terrain Models

Isocontours (also isopleths, isolines, level sets) are commonly used to visualize real-valued data defined over a 2D plane according to a set of given isovalues. To support the 3D landscape metaphor for information visualization, a 3D stepped terrain can be derived by lifting and extruding isolines to their particular isovalue, but typically requires triangulation of the resulting surface representation in a preprocessing step. We present a concept and rendering technique for triangle-based terrain models that provide interactive, adaptive generation and visualization of such stepped terrains without preprocessing. Our fully hardware-accelerated rendering technique creates additional step geometry for each triangle intersecting an iso-plane on-the-fly. Further, an additional interpolation schema facilitates smooth transition between established 3D terrain visualization and its stepped variant.