Layout Algorithms
In addition to the interactive tools (line and arc), Illuminator provides automatic layout algorithms accessible from the Layout menu or the Layout window.
Force-Directed (Spring) Layout
A live simulation where nodes repel each other while edges act as springs pulling connected nodes together. The layout runs continuously in the background and can be toggled on/off from the Layout menu or window.
| Parameter | Range | Description |
|---|---|---|
| Repulsion strength | 0 – 50,000 | Controls how strongly nodes push each other apart |
| Spring strength | 0 – 2 | Controls how strongly edges pull connected nodes together |
| Ideal edge length | 1 – 1,000 | Target rest-length distance between connected nodes |
| Fix Selected Nodes | Toggle | Pin selected nodes in place so the simulation does not move them |
The spring layout is especially useful during exploration: enable it, then select and fix key nodes to anchor parts of the graph while the rest settles into a readable arrangement.
Random Layout
Positions all selected nodes at random locations. Useful as a starting point before applying a force-directed or GRIP layout.
| Parameter | Range | Description |
|---|---|---|
| Spacing | 1 – 100 | Controls how spread out the random positions are |
GRIP Layout
A multi-level graph drawing algorithm that produces high-quality layouts for large graphs. It works by coarsening the graph into progressively smaller versions, computing a layout at the coarsest level, and then refining it back down to the original graph.
| Parameter | Range | Description |
|---|---|---|
| Ideal edge length | 1 – 100 | Target edge length for the layout |
| Rounds per level | 1 – 50 | Number of refinement iterations at each coarsening level. More rounds produce better layouts but take longer. |
GRIP is well-suited for graphs with hundreds or thousands of nodes where force-directed simulation would be too slow to converge.