1, .5));
    }
    envGradients.push(grad);
  }

  function degToRad(deg) {
    return deg * Math.PI / 180;
  }

  const data = {
    rotation: 20,
    normals: true,
    eyeToSurface: true,
    addedVectors: true,
    reflection: true,
    multipleRays: false,
  };
  const gui = new GUI();
  GUI.setTheme('float');
  gui.onChange(render);
  gui.add(data, 'rotation', {min: -70, max: 70});
  gui.add(data, 'multipleRays');
  gui.add(data, 'normals');
  gui.add(data, 'eyeToSurface');
  gui.add(data, 'addedVecto