As an exercise, please design a scene that generates the following:
There are four spheres on a table. A fifth one is placed on the four spheres. When you generate this scene, please make sure that the top sphere should only touch the bottom four spheres. It cannot be floating in space or intrude the four bottom spheres. You can use whatever colors, camera position and light sources as long as all shapes, except for one or two table legs, must be clearly shown.