Edge Bundling

This demo shows how edge bundling can be applied for reducing visual cluttering in dense graphs.

The edge curves are drawn using piecewise cubic bezier curves with gradient colors from dark-blue (that starts from the source node) to light-blue (that leads to the target node of the edge). For the approximation of the edge curves, a CurveFittingStage is applied.

For circular layouts, a circular-sector style is used for the visualization of the nodes.

Things to Try

• Select one of the layout algorithms that support edge bundling using the combo-box in the toolbar.
• Modify the strength of the bundles using the slider in the toolbar and notice how this change influences the shape of the curves of the bundled edges. Values close to 1 lead to tight bundles, while values close to 0 lead to straight-line non-bundled edges.
• Hover over an edge to highlight its path and its source and target nodes. The edges are highlighted also with gradient colors from red (source node) to gold (target node).
• Hover over a node to highlight its adjacent edges.
• Toggle the color scheme from the toolbar. By default, the color of each edge is determined by the angle formed by its source and target ports.
• Right-click on a node to open a popup-menu and determine whether the edges adjacent to the particular node or to all other currently selected nodes should be bundled or not.
• Right-click on an edge to open a popup-menu and determine whether the particular edge or all other currently edges should be bundled or not.

Note that the force-directed based routing of BundledEdgeRouter is not recommended for large graphs since high values of bundling strength affect the routing performance. Prefer one of the other two options instead.