Inhomogeneous Force-Directed Layout Algorithms in the Visualisation Pipeline: From Layouts to Visualisations

The visualisation pipeline approach is a flexible and extensible technique for generating visualisations. The basic pipeline functions involve the capture and representation of data, the computation of geometry and the presentation of visual output. Data is represented in XML at each stage and is successively transformed, typically by XSLT transformations, as it moves through the pipeline. A force-directed layout engine, Angle is one of the major components in the computation of 2D and 3D geometry. In this paper, we describe inhomogeneous force models and their implementation in Angle. These allow a richer variety of properties and relationships of the underlying graph and application domain to be included in the visualisation. We present examples from our software visualisation research.