Eidomatic experimentations on alteration of spatial perception by using colours

Ancient Greeks already had expertise in the use of colour effects to alter perception of architectural volumes and spaces. Awareness of these techniques evolved throughout history thanks to the Theory of Colours, based primarily on phenomenological observations. The advent of Gestalttheorie and Abstractionism then triggered a reexamination of these issues from a much more conceptual standpoint. Recent studies on chromatic illusions and effects, carried out by contemporary science, do not just allow us to address the subject of perception of Architecture in a new way: they also enable us to reconstruct certain types of stimuli, hitherto only meaningfully obtained with two-dimensional graphic models, through digital modelling of three-dimensional architectural spaces. Thus, in this paper we analyse the phenomena of chromostereopsis, apparent contraction of edge angles, chromatic induction, and neon colour spreading. We then propose some experimental three-dimensional virtual models, derived from the two-dimensional models of graphic stimuli pertaining to the aforementioned optical effects.