CAD-data is in general structured according to a layer-model, where color, linetypes and blocknames can be used to make more difference.
GIS-data is in general structured according to a feature-model, where objects from the same kind resides in the same feature-table provided with their specific attributes.
AcClassify – an AutoCAD Map utility from Autodesk Consulting – can filter CAD-data, based on various CAD-properties. AcClassify can “recognize” for example pipes of a certain type. After that AcClassify can migrate those CAD-entities into their corresponding GIS-features and optionally “tanslate” for example color-codes into diameters or linetypes into materials.
The major challenge encountered during this process is due to the lack of rigid attribute association with an AutoCAD DWG. AcClassify is designed to collect expertise around these DWG-entities to create a migration-schema which “maps” the unbound attributes to columns in a table, such as found in GIS database-tables.
AcClassify is a modular migration tool which is designed to work on a variety of input sources and output targets. It archives this by de-coupling the input and output phases from the classification engine with modules called adapters, configured in XML-config files.