This example shows a yellow smiley face rendered as an SVG, with black-outlined circular eyes and an arc-shaped mouth. It demonstrates how to build a reusable D3 shape generator—specifically `d3.arc()`—and integrate it with React components. The visualization uses React 16.9 and D3 v6, with the face centered in a 960×500 viewport, and the mouth path is generated from an arc with inner and outer radii. The React component renders the SVG elements directly, while D3 handles the geometry calculations for the mouth.