Distributed force-directed graph layout and visualization

While there exist many interactive tools for the visualization of small graphs and networks, these tools do not address the fundamental problems associated with the visualization of large graphs. In particular, larger graphs require much larger display areas (e.g., display walls) to reduce visual clutter, allowing users to determine the structure of large graphs. Moreover, the layout algorithms employed by these graph visualization tools do not scale to larger graphs, thereby forcing users into a batchoriented process of generating layouts offline and later viewing of static graph images. In this paper, we present a parallel graph layout algorithm based on the Fruchterman-Reingold force-directed layout algorithm and demonstrate its implementation in a distributed rendering environment. The algorithm uses available distributed resources for both compute and rendering tasks, animating the graph as the layout evolves. We evaluate the algorithm for scalability and interactivity and discuss variations that minimize communication for specific types of graphs and applications.