Drawing Decorated Graphs

Graph drawing algorithms are generally concerned with abstract graphs. Nodes are displayed as small points and edges as thin lines. Their real expansion on screen is neglected, since it is much smaller than unit distances between objects. In many applications this assumption is not adaequate, for example, when nodes vary much in size and edges have a real width. Then the visualized objects are multi-featured diagrams. We introduce a 3G approach to draw such diagrams. 3G combines graphs, geometry and graphics into decorated graphs. In this paper we discuss some well-known graph drawing algorithms and pinpoint problems arising from their generalization to decorated graphs.