era, transforms,
      elapsedTime, initialTime,
      fixedLight = false,
      dxSphere = 0.5,
      dx_cone = 0.15,
      spherePosition = 0,
      conePosition = 0,
      animationRate = 300,
      simulationRate = 30;

    function configure() {
      // Configure `canvas`
      const canvas = utils.getCanvas('webgl-canvas');
      utils.autoResizeCanvas(canvas);

      // Configure `gl`
      gl = utils.getGLContext(canvas);
      gl.clearColor(0.9, 0.9, 0.9, 1);
      gl.clearDepth(100);
      gl.ena