Depth-4:

The artists who use the sidewalk rather than a canvas create illusions using depth. The picture below is of a drawing of a dungeon that appears to be three-dimensional. The artist utilized a few pictorial cues in order to make and illusion of a three-dimensional dungeon on a two-dimensional surface, the sidewalk. The artist used light and shadow as well as linear perspective, even though there is no vanishing point for the lines. The lines at the bottom of the dungeon are shorter than those that are supposed to be the top. Even though they are all on the same surface, this makes the lines that appear to be at the floor of the dungeon appear farther away than the lines that bring the dungeon to the surface. Light and shadow are also very important monocular cues that lead to this illusion. The artist used shadows and lighting to create much of the depth we see even though there is no depth to the sidewalk. The pictorial cues in this work of art are what create an illusion in our minds. Because we see depth, our brains are tricked into thinking that this is image three-dimensional rather than a two-dimensional drawing.