Squares ↔ Hexagons

These aren’t regular hexagons; they’re too tall.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

path {
  fill: none;
  stroke: #000;
  stroke-width: .6px;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var width = 960,
    height = 500,
    size = 50,
    offset = 0;

var voronoi = d3.geom.voronoi()
    .clipExtent([[-1, -1], [width + 1, height + 1]]);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

var g = svg.selectAll("g")
    .data(voronoi(vertices()))
  .enter().append("g");

var path = g.append("path")
    .attr("d", function(d) { return "M" + d.join("L") + "Z"; });

var circle = g.append("circle")
    .attr("transform", function(d) { return "translate(" + d + ")"; })
    .attr("r", 2);

d3.timer(function() {
  ++offset; if (offset > size) offset -= size;
  var data = vertices();
  path.data(voronoi(data)).attr("d", function(d) { return "M" + d.join("L") + "Z"; });
  circle.data(vertices).attr("transform", function(d) { return "translate(" + d + ")"; });
});

</script>

https://d3js.org/d3.v3.min.js