{"version":"1.0","type":"rich","title":"Point-Along-Path Interpolation","description":"Two nested, closed Catmull–Rom splines define the paths in this SVG animation. Clicking anywhere adds a colored circle that first collapses to the inner path’s start, then follows the outer path via a tween that switches between the two paths partway through the animation. The code uses D3 v3’s `transition.attrTween` with the native SVG `getTotalLength` and `getPointAtLength` methods to interpolate each circle’s position, while a text element displays the tween progress as a percentage.","provider_name":"VizHub AI Studio","provider_url":"https://next.vizhub.com","html":"<iframe src=\"https://next.vizhub.com/viz/gist-77dff069d00125150b9dc73935e45c8c?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"1\"></iframe>","width":960,"height":500,"cache_age":3600}