GDAL is a C++ translator library for more than 200 raster and vector geospatial data formats. It offers an API for a variety of languages such as C, C++, Python, Perl, C# and Java
vdPConsulting has investigated whether and how this GDAL/OGR functionality can be implemented in a C# plugin in AutoCAD.
The import of the BGT/IMGeo is implemented as a Proof of Concept. Processed to NLCS-layers based on the features. At a later stage this can always be further broken down based on multiple properties. By keeping the fill and outline separated from each other, a simple Layer-command can be used to turn the fill off and switch to a line map.
Ask the cadgis-consultant.