This example visualizes the movement of 30 random points through animated density contours. As the points drift within the SVG canvas, `d3.contourDensity()` computes ten density levels, which are drawn as steel-blue contour paths using `d3.geoPath()`. The points themselves are rendered as small unfilled circles. The data is generated randomly rather than from an external file. The animation is driven by `d3.interval()`, which triggers an update every 200 milliseconds, moving each point by a random offset and recomputing the evolving contours in real time.