The answer to this question might seem simple, but it might not be obvious to those who have no experience creating 3D games or applications. In reality, 3D graphics are just an illusion. They are flat 2D images on a computer monitor, television screen, or phone display.
In the real world, your eyes work together to create an image that contains visual perspective. Objects appear to be smaller the farther they are away from you physically. Imagine you are standing in the middle of perfectly straight and flat railroad tracks. If you look down at your feet, the rails appear to be some distance apart. As you let your eyes move towards the horizon and look farther down the tracks, it appears that the track rails become closer to each other the farther they are away from you. Having two eyes adds to this depth perception because each eye has a slightly different view. They help to see slightly different angles of objects.This difference is even greater for objects near to you. If you alternate closing each eye, you see objects move left and right.
When you create 3D graphics, perspective is an illusion. When you are working with 3D graphics concepts, remember that you are really creating a 2D image that is displayed on the screen. Many parts of the graphics pipeline have nothing to do with 3D at all and work only on the pixel level.A friend of mine once described to me a helpful way to look at developing 3D graphics games. He related creating 3D graphics to how great painters create stunningly realistic pieces of art.Although to a viewer standing still the painting can appear to represent real 3D objects in the world, it is still just layers of paint on flat canvas. They are illusions just like computer-generated 3D graphics.
So what are 3D graphics? They are computer-generated images that give the appearance of depth and perspective, but in reality, they are just flat 2D images when displayed.
