In the image above the red rectangle appears to float across the interior of a building that has been blackened by fire. The illusion of coherence is created by controlling the optical viewpoint and is only visible from one specific view point. Outside of this viewpoint, the shapes deconstruct and the viewer can see them for what they really are, patches of colour placed on various surfaces that are designed to line up when seen from the position from where the photograph was taken. Rousse would have used a camera viewfinder set up on a tripod to constantly check the construction of the piece, instructing his construction team to make a drawing that would line up from the point of view of the viewfinder, which when finished would be coloured in red. Some of the more complicated versions of these constructions which involve deep space also have to contain colour adjustments to overcome the way that atmospheric colour space operates. The areas much further back having to be painted in slightly brighter tones so that they optically move forward into the same space as areas painted on much closer surfaces.
An artist that operates in the same territory as George Rousse is Felice Varini.
In the images above you can see that Varini's illusion only operates from one point and as you move away from that point the shapes that make up the image distort and break down into their individual forms. This type of illusion is totally site specific and can't really be appreciated unless you experience one 'in the flesh'. Varini at times works on a huge scale and the project management skills needed as well as the technology and workforce required are tremendous, but he would have had to start somewhere and I would suggest he developed these ideas by researching the history of anamorphosis.
William Kentridge's film ‘Whatwill come’ is a combination of anamorphic projection and animated film projection. Kentridge uses the mirrored cylinder anamorphic illusion to reflect the various states of emotional disturbance brought on by political tension.
Kentridge has used the mirrored cylinder anamorphic effect several times and was himself influenced by Scottish images of Bonnie Prince Charlie. In response to the brutal English crackdown on his followers when Scottish households who were found to contain a portrait of Bonnie Prince Charlie were imprisoned or worse, supporters turned to anamorphic portraiture.
Again these distortions relate to the way images can be 'hidden' so that in times of political tension images of political favourites could be hidden in plain sight.
These ideas don't always have to be about difficult emotional or political issues, they can sometimes simply be used to entertain.
The practical issues surrounding this type of work are to do with first of all getting to grip with how perspective works and there is an extensive post on the technical aspects perspective here.
However there is a very simple way of starting this sort of work and that is that you work with at least one other person and you direct them to make changes in relation to your viewpoint, usually by looking through the viewfinder of a camera set up on a tripod.
Hopefully by exploring this area you can get your audience to 'look again', to become aware that what you see isn't always what you get.
Richard Wright (Anamorphic projections)