Open source viewing capability for CDB Common Database with osgEarth
CDB Plugin osgEarth
GAJ Geospatial Enterprises LLC open source viewing capability for CDB
Visualization of CDB can now be done through the use of open source software. This is accomplished using the osgEarth library. The capability is dependent on several
other open source libraries such as the Geospatial Data Abstraction Library (GDAL). GDAL provides an abstraction layer to access to the myriad of different geospatial
raster and vector formats that the industry needs to support including the native formats used in CDB. Along those lines a similar library support for visualization
applications of geospatial data, the OpenSceneGraph (OSG) provides a basic scene graph for the visualization process as well as the means to load and display OpenFlight
models which are a component of CDB. The osgEarth libraries provide a robust geospatial interface for the OSG libraries. Both of these libraries support the use of GDAL
to provide the file level access to the raster and vector elements of visualization. Each of these libraries has a number of additional dependencies and optional capabilities
that are beyond the scope of this document with the exception of libcURL. LibcURL (the multiprotocol file transfer library) provides support to both GDAL and osgEarth that
allows them to access OGC web services. An open source plugin to the osgEarth libraries has been created that allows CDB content to be displayed in applications utilizing
osgEarth. At present the implementation does not as yet fully implement all of the capabilities that are defined in the CDB best practices however it does provide access
for basic visualization of a CDB dataset. Full implementation of all of the CDB capabilities is a future goal of the project.
For questions on exactly what aspects of the CDB specification are implemented in the drivers feel free to contact us here.
You can find osgEarth here. Link to osgEarth
You can find OSG here. Link to OpenSceneGraph
You can find the Geospatial Data Abstraction Library here. Link to GDAL
You can find the cURL Library here. Link to libcURL
The osgEarth_cdb repository contains source code for the CDB implementation. Support for CDB in osgEarth versions 2.6 and 2.7 as well as CDB OpenFlight driver support for
OSG versions 3.2.1 and 3.4.0 can be found in the repository. OsgEarth divers exist for Imagery, Elevation, Geospecific Features, and Geotypical Features. The osgEarth_cdb
driver addresses the issue of using CDB in a whole earth view by creating a CDB specific cache for levels of detail less than a geocell.
Plans exist to expand the layers that can be viewed in osgEarth in the future.
You can find the osgEarth_cdb repository here. Link to osgEarth_cdb
osgEarth Viewer with Global CDB Coverage Loaded video
osgEarth Viewer with Colorodo Springs CDB Coverage (contains both geo-specific and geotypical features) video
