Smooth, Interactive Rendering and On-line Modification of Large-Scale, Geospatial Data

Visualising large-scale geospatial data is a demanding challenge that finds applic- ations in many fields, including climatology and hydrology. Due to the enormous data size, it is currently not possible to render full datasets interactively without significantly comprom- ising quality (especially not when information changes over time). In this paper, we present new approaches to render and interact with detail-varying Light Detection and Range (LiDAR) point sets. Fur- thermore, our approach allows the attachment of large-scale geospatial meta information and the modification of point attributes on the fly. The core of our algorithm is a dynamic GPU- based hierarchical tree data structure that is used in conjunction with an out-of-core, Level- of-Detail (LoD)-Point-based Rendering (PBR) algorithm to modify data on the fly. This com- bination makes it possible to augment the ori- ginal data with dynamic context information that can be used to highlight features (e.g., routes, marked areas) or to reshape the entire data set in real-time. We showcase the usefulness of our algorithm in the context of disaster management and illustrate how decision makers can discuss a flood scenario covering a large area (spanning 300 km2) and discuss hazards, as well as related protection measures, interactively. One of our presented reference point sets includes parts of the AHN2 data set (14 TB of LiDAR data in total). Previous rendering algorithms relied on a long offline preprocessing (several hours) to ensure a quick data display. This step made any changes to the data impossible. With our new approach, we can modify point sets without requiring a new preprocessing run.

@Misc { KTE13a,
  author       = "Kehl, Christian and Tutenel, Tim and Eisemann, Elmar",
  title        = "Smooth, Interactive Rendering and On-line Modification of Large-Scale, Geospatial Data",
  howpublished = "Open ICT 2013",
  year         = "2013",
  url          = "http://graphics.tudelft.nl/Publications-new/2013/KTE13a"
}