M. Lambers and A. Kolb, Ellipsoidal Cube Maps for Accurate Rendering of Planetary-Scale Terrain Data,
Proc. Pacific Graphics (Short Papers), Sep. 2012.
(PDF download. The definitive version is available at http://diglib.eg.org/ in the Pacific Graphics 2012 short paper section.)
Computer Graphics Group, University of Siegen, Germany. Contact: Martin Lambers.
Using an ellipsoidal planet model circumscribed by a cube (left) combined with a carefully chosen map projection (middle) and a precision-aware organization of geometry computations results in improved accuracy for rendering of planetary-scale, high-resolution terrain data (right).
Ellipsoidal Cube Maps (ECMs) store planetary-scale terrain data in quadtree hierarchies. ECMs have the following advantages:
This site provides demo software for ECMs, consisting of three parts: libecmdb, which implements the basic model and projection, ecmdb, which builds ECM databases from remote sensing data, and ecmview, which renders ECM databases interactively.
This software is licensed under the terms of the GNU GPL version 3 or later. If you want to use it under different license terms, please contact us.
This software was written for current Linux systems. Porting it to other systems should be straightforward, but was not done yet.
To help you get started, the script build-ecm.sh downloads the latest version of the ECM software, builds it, and installs it into a directory of your choice. Additionally, the script creates two small example data bases. The script was tested on Debian and Ubuntu, but should work on all recent Linux systems.
Ubuntu packages are available from http://launchpad.net/~marlam/+archive/ecm-planet/:
sudo add-apt-repository ppa:marlam/ecm-planet
sudo add-apt-repository ppa:marlam/gta
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install libecmdb libecmdb-dev libecmdb-doc ecmdb ecmview
Version 0.7.0 of all packages is released. This version adds support for SAR amplitude images, including interactive despeckling and dynamic range reduction. The relevant methods are described in the following papers:
This library implements the basic data structure and the map projection.
This tool builds ECM databases from elevation models, orthophotos, or other remote sensing data readable by GDAL.
This program renders planetary terrain data from ECM databases.
Please note that ecmview is a research prototype and not a polished end user product. It is neither a fully-featured planet viewer nor a performance-optimized terrain renderer. It is simply a demo program for ECMs. Nevertheless, it has some interesting features:
This software is targeted at powerful graphics hardware. It was written and tested with a NVIDIA GTX480 GPU. It also runs on less powerful hardware (e.g. NVIDIA 8800GTX or Intel Core-i7 integrated graphics), but don't expect interactive frame rates at full detail levels.