Flatten sphere w/ d3 and svg path transitions! by mpmckenna8

index.html

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

path {
  fill: none;
  stroke-linejoin: round;
}

.sphere,
.graticule {
  stroke: #aaa;
}

.equator {
  stroke: red;
  stroke-width: 2px;
}

</style>
<body>
<script src="//d3js.org/d3.v3.js"></script>
<script src="//d3js.org/d3.geo.projection.v0.min.js" type="text/javascript"></script>
<script src="//d3js.org/topojson.v1.js"></script>

<script>

var width = 1060,
    height = 600;

var projection = interpolatedProjection(
    d3.geo.orthographic()
        .rotate([10, -10])
        .center([-10, 10])
        .scale(240)
        .translate([width / 2, height / 2]),

        d3.geo.equirectangular()
        .scale(153)
        .translate([width / 2, height / 2])
      //  .precision(.1);

/*
        d3.geo.conicEqualArea()//d3.geo.albers()
        .scale(145)
        .translate([width / 2, height / 1.5])
  */
        );

var path = d3.geo.path()
    .projection(projection);

var graticule = d3.geo.graticule();

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

    var feature = svg.selectAll("path");




d3.json('brazilWor.json',function(world){


console.log(topojson.feature(world,world.objects.countries110).features)
  svg.selectAll('.coun')
  .data(topojson.feature(world,world.objects.countries110).features).enter().append('path')
  .attr('d',path)
  .on('hover',function(){
    //    console.log(this)
    return this.style('fill','purple');
  })
  .attr('class',function(d,i){
    //    console.log(i + 'this is for the countries class');
    return 'coun'})
    .style('fill', 'blue');

console.log(world);


svg.append("path")
.datum({type: "Sphere"})
.attr("class", "sphere")
.attr("d", path);


svg.append("path")
    .datum(graticule)
    .attr("class", "graticule")
    .attr("d", path);

svg.append("path")
    .datum({type: "LineString", coordinates: [[-180, 0], [-90, 0], [0, 0], [90, 0], [180, 0]]})
    .attr("class", "equator")
    .attr("d", path);



feature = svg.selectAll("path");



animation();

})

function animation() {
  svg.transition()
      .duration(10500)
      .tween("projection", function() {
        return function(_) {
          projection.alpha(_);
          feature.attr("d", path);
        };
      })
    .transition()
      .duration(2500)
      .each("end", animation);
}



function interpolatedProjection(a, b) {
  var projection = d3.geo.projection(raw).scale(1),
      center = projection.center,
      translate = projection.translate,
      α;

  function raw(λ, φ) {
    var pa = a([λ *= 180 / Math.PI, φ *= 180 / Math.PI]), pb = b([λ, φ]);
    return [(1 - α) * pa[0] + α * pb[0], (α - 1) * pa[1] - α * pb[1]];
  }

  projection.alpha = function(_) {
    if (!arguments.length) return α;
    α = +_;
    var ca = a.center(), cb = b.center(),
        ta = a.translate(), tb = b.translate();
    center([(1 - α) * ca[0] + α * cb[0], (1 - α) * ca[1] + α * cb[1]]);
    translate([(1 - α) * ta[0] + α * tb[0], (1 - α) * ta[1] + α * tb[1]]);
    return projection;
  };

  delete projection.scale;
  delete projection.translate;
  delete projection.center;
  return projection.alpha(0);
}

</script>