The Fill radio buttons are used to change the rendering of the three-dimensional models. If the Transparent radio button is selected, the atoms of the molecule are displayed as spherical outlines. All parts of the molecule can be viewed at once, including any atoms that would normally be obscured from sight. If the Solid radio button is selected, all of the atoms are displayed as opaque, black spheres. If the Coloured radio button is selected, the atoms are displayed as opaque spheres, but they receive distinguishing colours. Finally, if the Shaded radio button is selected, the model is exposed to a light source.
