Dynamic Mapping of Raster-DataFor 3D Geovirtual Environments :Dynamic Mapping of Raster-DataFor 3D Geovirtual Environments Matthias Trapp, Jürgen DöllnerHasso-Plattner-Institute, University of Potsdam, Germany 13th International Conferenceon Information Visualisation14-17 July


motivation :motivation Using 3D geovirtual environments as scenery for visualization of dynamic geo-referenced thematic data


motivation :motivation Using 3D geovirtual environments as scenery for visualization of dynamic geo-referenced thematic data Preprocessing Time: days-hours Preprocessing Time: hours-minutes Preprocessing Time: minutes


wrap-up: challenges & goals :wrap-up: challenges & goals Strong coupling of geometry and appearance: Real-time rendering constraints Large-scale data sets require specific out-of-core renderer Results in (time-consuming) data pre-processing ? Cannot be used to visualize time-critical data Goals: partially decoupling geometry and appearance to… …enable dynamic multi-texture mapping …enable color transfer function …for a large number of mapping configurations …in real-time


overview: dynamic texture mapping :overview: dynamic texture mapping Given input data: 3D point (fragment) of original model Data & color layers Mapping parameterizations Requested: final color Data & color layers: 1D/2D/3D image/textures data values, masks color gradients


texture coordinate generation :texture coordinate generation Projective texture mapping [Everitt 2001] Orthogonal projection matrix: U V


color transfer functions :color transfer functions Describes color mapping of data values Define blending equations between mappings


rendering at a glance :rendering at a glance Extending OpenGL/DirectX multi-texturing pipeline Single-pass rendering: Per-fragment dynamic texturing using shader programs GPU Data representation: texture arrays Projective mappings encoded in texture-buffers Performance evaluation:


application examples :application examples Hierarchical combination of raster data layers Building category data Traffic frequency data


application examples :application examples Object or route highlighting Landmark objects Landmark objects Route


application examples :application examples Projective symbols to facilitate the design of interactive 3D digital maps


application examples :application examples Focus + context visualization: 2D magic lenses


conclusions :conclusions Summary: Extendable concept for dynamically mapping 2D raster-data Approach based on projective texture mapping Fully-hardware accelerated implementation Limitations: Works only for 3D GeoVE that can be approximated by a plane Limited texture resolution Future Work Extend color transfer to style transfer functions


thank you... :thank you... Contact: Matthias Trapp matthias.trapp@hpi.uni-potsdam.de Jürgen Döllner juergen.doellner@hpi.uni-potsdam.de Computer Graphics System Group www.hpi.uni-potsdam.de/3d Researchgroup 3D-Geoinformation www.3dgi.de