An anamorphic illusion occurs when a pattern or image resembles reality only from a very specific angle or point of view. If you move, the image changes. Perhaps the illusion of the image created breaks down completely. All of those 3-D sidewalk chalk paintings are anamorphic. It all depends on perspective. Stand in the wrong place and the illusion doesn’t work.
Here is a beginner illusion to whet your appetite. I saw this a few months ago and just never got around to sharing it.
I’m not saying the illusion is beginner; props to the people that designed and filmed it. But you need to see that before even trying to what this: