According to a paper written by archaeologist Christian Sapin, Christian Père and two other engineering students from the local ENSAM (National Arts and Crafts College) in Cluny attempted to recreate the abbey on their Atari PCs. They failed to produce an accurate representation, so solicited participation from IBM. IBM offered the computing power of their RS 6000 machines with CAD (computer-aided design) software, specifically CATIA and TDImage programs, for modeling the building volumes and rendering realistic surfaces and textures.
At the time, archaeologists and art historians like Christian Sapin commented that they had not been consulted for the film, and more recent discoveries and insights than Kenneth John Conant (from 1968) had not been taken into account. Also, previous building stages of the abbey were ignored. Thus the production became more of a stylistic exercise, in the sense of what could be achieved visually for public presentation, than a reliable source for study. This issue was acknowledged by the producers in their documentation, and fully addressed in later reconstruction projects.
As reported by the Cahiers of the Dutch Society for History and Informatics, the innovative architectural design software developed to create the abbey reconstruction soon proved to be more than a powerful visualization tool. When the original measurements were modeled as visual elements, the unerring accuracy of the computations produced a conspicuous hole between the walls and the roof, a clear indication of an error in the underlying data.
According to an article in the Dutch NRC newspaper, the lack of details outside and inside the abbey shown in the documentary wasn't just due to rendering software limitations. The creators wanted to model only decorations based on archaeological evidence.
Even though the project was considered a major breakthrough in photo-realistic digital recreation, there had been other, somewhat less sophisticated historical reconstructions in France before, like the 3D remodeling of the Amon-Re temple complex in Karnak from the late 1980s by Robert Vergnieux, contrasting with the highly advanced evocation of 1789 Paris for the 1989 bicentennial celebrations by the Ex Machina company. In 1990, Christian Sapin presented a model of the various construction phases of the Saint-Nazaire Cathedral and cloister in Autun, followed by a digital impression of antique Marseille, called 'Les Envois de Marseille', by Paul Quintrand and François Pages in 1991.