Amazing trompe l'oeils

The works of Swiss painter Felice Varini are magical illusions. They can only be viewed from a single point in space, otherwise they make no sense. In person, the pieces appear two-dimenensional and floating. In photographs, they seem to be superimposed.Here is a simple example. This painting appears to be a cross over a doorway.When the point of view changes, you can see that it's painted onto