.block

## .block
license: gpl-3.0

## README.md

      
        

          Raw
        
        
          
            
          
          
            
              README.md
            
          
        
      
    
  
    By changing the scale and clip angle of an orthographic projection, this example creates two concentric spheres to give the appearance of floating landmasses. Inspired by Derek Watkin’s Faux-3D Arcs.

  

  

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

body {
  background: #fcfcfa;
}

canvas {
  position: absolute;
  top: 0;
  left: 0;
}

.blur {
  -webkit-filter: blur(6px);
  filter: blur(6px);
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>

var width = 960,
    height = 960,
    speed = -1e-2,
    start = Date.now();

var sphere = {type: "Sphere"};

var projection = d3.geo.orthographic()
    .translate([width / 2, height / 2])
    .precision(.5);

var graticule = d3.geo.graticule();

var canvas1 = d3.select("body").append("canvas"),
    canvas2 = d3.select("body").append("canvas").attr("class", "blur"),
    canvas3 = d3.select("body").append("canvas");

d3.selectAll("canvas")
    .attr("width", width)
    .attr("height", height);

var context1 = canvas1.node().getContext("2d"),
    context2 = canvas2.node().getContext("2d"),
    context3 = canvas3.node().getContext("2d");

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

projection.scale(width / 2.3).clipAngle(90);

context1.beginPath();
path.context(context1)(sphere);
context1.lineWidth = 3;
context1.strokeStyle = "#000";
context1.stroke();

context1.beginPath();
path(sphere);
context1.fillStyle = "#fff";
context1.fill();

context2.fillStyle = "rgba(0,0,0,.4)";
context3.strokeStyle = "rgba(0,0,0,.2)";

d3.json("/mbostock/raw/4090846/world-110m.json", function(error, topo) {
  if (error) throw error;

  var land = topojson.feature(topo, topo.objects.land),
      grid = graticule();

  d3.timer(function() {
    context2.clearRect(0, 0, width, height);
    context3.clearRect(0, 0, width, height);

    projection.rotate([speed * (Date.now() - start), -15]);

    projection.scale(width / 2.3).clipAngle(90);

    context2.beginPath();
    path.context(context2)(land);
    context2.fill();

    context3.beginPath();
    path.context(context3)(grid);
    context3.lineWidth = .5;
    context3.stroke();

    projection.scale(width / 2.2).clipAngle(106.3);

    context3.beginPath();
    path(land);
    context3.fillStyle = "#737368";
    context3.fill();

    projection.scale(width / 2.2).clipAngle(90);

    context3.beginPath();
    path(land);
    context3.fillStyle = "#dadac4";
    context3.fill();
  });
});

d3.select(self.frameElement).style("height", height + "px");

</script>

## thumbnail.png

      
        

          Raw
        
        
          
            
          
          
            
              thumbnail.png