Because GenGMF uses the concepts of GMF it is suggested to get a glimpse of what GMF is or does in the GMF documentation.
GenGMF uses standard GMFGraph model elements to let you define the common layout for a set of figures like in GMF. “Like” means that you could define one figure — called “Template” — which is used for several mapped figure types. This mapping is done in GenGMF specific “Descriptors” connecting the template with a element type from the meta model and a tool from a standard GMFTool model like it is done in the GMFMap model.
A Transformation merges the Templates and Descriptors and generates a GMFGraph as well a GMFMap model. For each specified Descriptor the Template contents will be copied and adapted to it. This process can be modified using Transformators.