src/index.html

<!doctype html>
<html>
  <head>
    <meta charset="utf-8"/>
  </head>
  <body>
    <canvas id="canvas" style="position: absolute; left: 0; top: 0;"></canvas>
    <script type="text/javascript" src="Cone.js"></script>
    <script type='text/javascript'>
      var Module = {
        canvas: (function() {
          var canvas = document.getElementById('canvas');
          canvas.addEventListener(
            "webglcontextlost",
            function(e) {
              console.error('WebGL context lost. You will need to reload the page.');
              e.preventDefault();
            },
            false
          );
          return canvas;
        })(),
        onRuntimeInitialized:  function() {
          console.log('initialized');
        },
      };

      // Use the export name to instantiate the app
      var app = vtkApp(Module);
      console.log('App created');
    </script>
  </body>
</html>