This example creates a generative grid of horizontal and vertical bars using D3.js, with a circular mask that reveals the intersection of the patterns. The visualization uses `select`, `range`, `append`, `attr`, and `join` to build SVG `rect` elements dynamically, while two masks (`circle-mask` and `circle-mask-2`) invert the visibility of the bars within a central circle. The result is a crosshatch of lines forming a negative-space circle at the center of the canvas, rendered in pure SVG without external data.