Many 2D patterns carry with them 3D information. We are just not trained to pick it up. our being so accustomed with seeing 2D patterns that our brain become lazy and treat them as 2D tessellation.
As many of the images shown in this site were 3 dimensionalised simply by shading them, so are many others that we overlook. Perhaps if we are more aware of 2D patterns hiding 3D info, we can find more interesting geometric patterns and structures.
The image above carry two different 3D infomation. Can you find out which ones? You might think that one of them is optical illusion because some octagonal loops overlap, but they are not.
