Flexible terrain representation using runtime surface reconstruction

Abstract

Terrain has a great potential as a reference for visual navigation, which can be utilized to access and manage information. From this standpoint the geometry of the terrain is a unique defining surface for all geographic applications as well as for any geo-related information. However, a data representation of terrain in threedimensions provides numerous challenges for visualization as well as for analytical purposes. Solutions that satisfy visualization criterions often appear to be less optimal for maintenance or scalability required by analytical applications and vice versa. This work proposes a geometric data representation of the terrain that respects both visualization and analytical applications. The solution can be used for an entire planet, which allows avoiding needs for performing conversions between cartographic projections and transformations between geodetic datums. The data representation provides good local geometric flexibility like TIN but also supports multiple levels of detail. Amounts of data can grow large gradually---it is possible to alter local areas only while leaving distant parts of the terrain unchanged, which is convenient for maintenance. Introduced approach is based on runtime construction of triangulated irregular network using Delaunay triangulation. The mass points used for the surface reconstruction are structured in order to support multiple levels-of-detail. The proposed representation allows managing terrain data in numerous detached repositories, which can be used for distributed solution.