index.html

## index.html
<html>
    <head>
        <title>
            [Visualizing Movement Data with D3.js]
        </title>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
        <script src="mviz.js"></script>
        <style>
            * {
                box-sizing: border-box
            }

            body {
                margin: 0px;
            }

          svg {
            position: relative;
            left: calc(50% - 250px);
          }
        </style>
    </head>
    <body>
        <div id="c1"></div>
        <script>run()</script>
    </body>
</html>

## mviz.js
// Variables
var skeleton;
var positions;
var figureScale = 6;
var h = 540;
var w = 900;
var gap = 0;
var skip = 1;
var traillength = 2;
var dataFile = {frames: "https://omid.al/moveviz/data/Walk_long.json",
                skeleton: "https://omid.al/moveviz/data/Skeleton_Walk.json"};

//******************************************************************//
var Mova = {};

Mova.Joints = function(parent, frames, className) {
    return parent.selectAll(className)
                 .data(frames.filter(function(d, i) {
                 return i % skip === 0;
                 }))
                 .enter()
                 .append("g")
                 .attr("class", className)
                 .attr("transform", function(d, i) {
                  return "translate(" + (i * gap) + ",0)";
                 })
                 .selectAll("joint")
                 .data(function(d, i) {
                 return d;
                 })
                 .enter();
};

Mova.Bones = function(parent, frames, skeleton, className) {
    return parent.selectAll(className)
                 .data(frames)
                 .enter()
                 .append("g")
                 .attr("class", className)
                 .selectAll("bone")
                 .data(skeleton)
                 .enter();
};

function run() {
    // Read the files
    console.log('Loading the data...');

    d3.json(dataFile.skeleton, function(error, json) {
        if (error) return console.warn(error);
        skeleton = json;
        d3.json(dataFile.frames, function(error, json) {
            positions = json;
            positions.splice(0, 160);
            positions.splice(positions.length-190, 190);

             var frames = positions.map(function(ff, j) {
                return ff.map(function(d, i) {
                return {
                    x: (d.x + 60) * figureScale,
                    y: -1 * d.y * figureScale + h - 10,
                    z: d.z * figureScale
                };
                });
            });


            svg = draw(frames);

            var fr = 1/30;
            var startTimeJ = Date.now();

            anim0(frames.slice(0,traillength),svg);

            window.setInterval(function() {
                f = traillength + Math.floor((Date.now() - startTimeJ)/1000 / fr);

                if (f > frames.length) {
                    startTimeJ=Date.now();
                    f = 0;
                }
                segment = frames.slice(f-traillength,f);
                anim(segment, svg, f);

            }, fr * 1000);

        });
    });
}

function draw(frames) {
   console.log('Drawing...');
  // Prep the environment
  var parent = d3.select("body").select("#c1");
  var svg = parent.append("svg")
    .attr("id","svg")
    .attr("width", w)
    .attr("height", h)
    .attr("overflow", "scroll")
    .style("display", "inline-block")
    .style("left", "calc(50% - "+w/2+"px)");

    window.parent.loaded();

    return svg;
}

function anim0(frames, svg) {
    var bones = Mova.Bones(svg, frames, skeleton, "boneanim");

    // Bones
    var boneFunction = d3.svg.line()
        .x(function(d,j,k) { return frames[0][d[0]].x; })
        .y(function(d) { return frames[0][d[0]].y; })
        .interpolate("linear");

    bones.append("path")
        .attr("d", boneFunction(skeleton))
        .attr("class","anim")
        .attr("stroke", "#666666")
        .attr("stroke-opacity", .8)
        .attr("stroke-width", .2)
        .attr("fill", "transparent");
}

function anim(frames, svg, f) {
    // Bones

    var boneFunction = function(d, k) {
        bf = d3.svg.line()
        .x(function(d) { return frames[k][d[0]].x + fu(k) * 0; })
        .y(function(d) { return frames[k][d[0]].y + fu(k) * 0; })
        // .interpolate("basis");
        .interpolate("step-after");
        return (bf(d));
    };


    svg.selectAll("g.boneanim")
        .data(frames)
        .selectAll("path.anim")
        .data(skeleton)
        .attr("d", function(d,j,k) {
            return boneFunction(skeleton,k);
        })
        .attr("fill", "transparent")
        .attr("fill-opacity", "0.2")
        .attr("stroke", "#666666")
        .attr("stroke-opacity",  function (d,i, k) {
            return 0 + 0.1 * k/traillength;
        })
        .attr("stroke-width", function (d,i, k) {
            return  1 +  k/traillength;
        });
}

function fu(k) {
    if (Math.random() < 0.2)
        return Math.random() * 50;
    else
        return 0;
}

## preview.png

      
          Raw
        
        
              preview.png