What is 3D streetpainting?
A 3D streetpainting is actually called an anamorphic painting. Anamorphosis is the technique used to distort a picture in such a way that from a vantage point it looks correct.
Normally you would view a picture in front of you, a 3D painting is on the floor and you view it from an angle, so the top of the picture is further away from you then the bottom. With anamorphosis you make it seem like there is no viewing angle.
History
At the beginning of the 15th century perspective drawing was invented in Italy to give paintings a more realistic view. The main observation in this was that the horizon is always at eye level from the viewer and that there are vanishing points.
At some point painters wanted to make murals on walls and ceilings where the view point was not straight in front, but from an angle. This gave them the problem that images seemed distorted. For this they had to use the anamorphosis trick. ’Leonardo’s eye’ by Leonardo Da Vinci is one of the earliest examples in a study of anamorphosis.
Standing on the view point you can best view a 3D painting with one eye to better fool your brain. Without depth perception the painting will better fit with the environment. For this reason a camera will register the illusion most perfect.