This example shows 100 unlabeled circular nodes clustering into four groups through a force-directed layout. The nodes are pushed in different directions based on their index, creating a visual separation of categories while the simulation runs. The visualization uses the D3.js v3 force layout with custom tick logic to apply directional forces, and renders the nodes as SVG circles with categorical colors from `d3.scale.category10()`. Clicking the background applies random jitter to all nodes and resumes the force simulation, while dragging individual nodes is supported via `force.drag`. A fade-in transition animates the SVG’s opacity on load.