Using the Graph Model
The IlvGraphModel class defines a suitable, generic API for graphs that have to be laid out with Views graph layout algorithms.
All the layout algorithms provided in Views are designed to lay out a graph model. This allows applications to benefit from the graph layout algorithms whether or not they use the Views grapher IlvGrapher). However, to make things very simple for the common case of applications that manipulate an IlvGrapher, it is not mandatory to work directly with the graph model except for some of the advanced features such as filtering.