title: 3D Lines disappear sometimes
body: <p>I am building 3d line chart from data </p>
  
  <p>here is the code <a href="http://ameetrana.yzi.me/demos/lines/" rel="nofollow">Demo</a></p>
  
  <p>the part of code that generate line is </p>
  
  <pre><code>     parentTransform = new THREE.Object3D();
              var _color = d3.scale.category10();
              for (var i = 5; i &gt; 0; i--) {
                  var material = new THREE.LineBasicMaterial({
                      // color: 0x0000ff,linewidth: 30
                       color: _color(i), linewidth: 50
                  });
                  var PI2 = Math.PI * 2;
  
                  var geometry = new THREE.Geometry();
                  var k = -10;
                      for (var j = 0; j &lt; 80; j=j+10) {
                          var _x = j;
                          var _y = (Math.floor(Math.random() * (50 - 10 + 1)) + 10);
                          var _z = i*5;
  
                          geometry.vertices.push(new THREE.Vector3(_x,_y,_z));
                          var _point = new THREE.SphereGeometry(0.8);
                          var material = new THREE.MeshBasicMaterial( {color: _color(i)} );
                          var sphere = new THREE.Mesh( _point, material );
                          sphere.position.set(_x,_y,_z);
                          parentTransform.add( sphere );
                      };           
                  var line = new THREE.Line(geometry, material);
                  line.material.linewidth = 2;
                  parentTransform.add(line);
              };
              scene.add( parentTransform );
  </code></pre>
  
  <p><strong>Sometime When I start to rotate/zoom line disappear</strong>.. only point stay there </p>
  
  <p>also I wanted to add 3 axis walls any help ? 
  I have experience with d3.js and new at Three.js so 
  any help will be most welcome  </p>