# HOOPS/3dGS classes

As previously mentioned, the HOOPS/3dGS-specific classes encapsulate the work of traversing/querying/exporting the HOOPS/3dGS scene-graph to an HSF file, as well as the work of reading an HSF file and mapping HSF objects to a HOOPS/3dGS scene-graph. Because HOOPS/3dGS-specific classes are derived from the base classes, (performing the above logic in overloaded versions of the Interpret and Execute methods), they provide a valuable reference of how to use the base classes, and their source code is included with the toolkit.