The GCD can derive a slope raster for you from your DEM within the associates surfaces tab of the survey library or through the GCD project explorer. The roughness surface will need to be derived from the raw point cloud file produced from a survey through using the project explorer (detailed below) or through the Roughness Analysis Submenu.
Adding Associated Surfaces Through the GCD Project Explorer
This video shows you how to use the project explorer dockable window to calculate a slope raster from a DEM already loaded to a GCD project.This video shows how to create a surface roughness raster from a raw point cloud and load it to a GCD project: