I have an incredible amount of respect for artists with the skill and patience to create these three-dimensional masterpieces. It must take countless hours to perfect the ability of fooling the eye with these optical illusions.
My only issue with such creations is that most people don’t realize these can only be viewed from a single fixed point in space. This clip does a good job of pointing out that the illusion only comes to life through the camera lens. Otherwise you can walk around the chalk art and the eye discerns the falsehood. In fact, if viewed from the wrong angle the art probably looks incredibly distorted and awkward. But when the mathematic perspective aligns at the “sweet spot,” everything pops. The multitude of images of “3D” chalk art floating around the internet have all been selectively photographed from the single point in space where the trompe l’oeil works its magic.