The transposition from colour to volume by means of digital fabrication: Op Art case study Juliana Harrison HENNO,1 Monica TAVARES,1 Henrique STABILE,3 1 School of Communication and Arts, University of São Paulo 2 Architecture and Urbanism College, University of São Paulo ABSTRACT This article is about the transposition of digital images by means of automated production, using the immaterial quality of colour from a light source as a parameter for recoding. In order to understand how the contemporary processes of digital fabrication can enable the conversion into a physical and three-dimensional image, some artworks by Vasarely were chosen, as their colour is a determining factor for obtaining volumetry. In Vasarely's artworks, the form-and-colour combination results from abstract compositions of serial and dynamic patterns, and it causes a multidimensional illusion in the human visual perception. The investigative approach will take into account how the concepts of colour definition can be converted into three-dimensional form. It will also identify the steps of the creative process and the heuristic methods adopted, which are seen as the creative routes for planning and accomplishing the discussed artworks. Moreover, the analysis will highlight how the dialectic between the immaterial versus the material is developed. Both of them determine new ways of creation. Thus, we start from the assumption that the artist who can use CAD / CAM technologies can also access tools that allow him to overcome limitations in his artistic and poetic propositions. 1. INTRODUCTION The automated production, technique that refers to prototyping and digital fabrication, is originally applied in areas such as mechanical engineering and product design, due to its industrial purposes. However, over the past few years, this type of production has been a fertile ground explored by architects and, most notably, by artists. Although its usage is still incipient in both areas, it has been gaining followers as this technology has becoming more accessible in universities’ laboratories and print bureaus. Regarding the field of visual arts, the automated production has been outstanding due to the increase of artist’s creative potential, ensuring new approaches in terms of the technical procedures to fabricate objects. By a numerical simulation of the object’s geometrical structure, it becomes possible to represent it both “physically” and three-dimensionally. When using such procedure, the artist experiments a new representation technique, based on numeric models that allow the transposition of the paradigm originally conceived on a three-dimensional physical model. Nevertheless, due to automated production procedures’ high complexity, it is expected the artist to be familiar with both virtual and numerical universes, as to make viable recoding and transposing of existing medias in the process. Therefore, the use of automated production in arts creates new possibilities of representation, making possible the physical execution of complex forms not before enforceable by manual methods.
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2. OP ART CASE STUDY In order to understand this scenario, three artistic experimentations that were made based on the use of digital fabrication1, will be analysed in this case study. By means of data transduction from an original artwork, new media approaches has been generated by the transposition occurred during the process, taking into account the variation of colour from a light source as a translation parameter. Three artworks by Victor Vasarely were chosen: Vonal Alto (1969), Cheyt Pyr (197071), Enigma 5 (1974). The above mentioned artist is one of the main references of the 60’s artistic movement known as Optical Art, or Op Art. His artworks suggest movement, resulted from the optical ilusion effects. Such poetic intended to turn the artwork receptor/spectator into a active participant, thus widening possibilities of engagement with the piece. The artist conducted a serie of colour experiments when studying movement and perception. Even though in a two-dimensional conception, Vasarely’s artwork herein analysed seems to gain volume by the use of colour contrast and tone colour schemes expressed in the piece. The optical effects that suggests the three-dimensional visualization result from the way the artist were used to dealing the relations beween colour and form. In the case studies to be presented, we intended to translate into volume the chromatic data from three different artworks by the artist, and such information was retrieved from the digitization of Vassarely’s original drawings. To better understand how the numerical simulation of an object´s geometric structure can enable its “physical” and three-dimensional representation, we will base our research on three artistic experiments that highlight the changes caused by the introduction of the automated production methods in the context of Visual Arts. The recodings happened through the use of parametric design and interaction processes, obtained with the help of 3D and generative softwares. The foundation of re-reading is sustained in the recoding of information from the RGB channels of the digitized artworks, so as to obtain volume that can be produced through the digital fabrication subtractive process 2. Although it sounds like a paradox, we can admit that this process gives materiality to the immaterial; in short, it increases the possibilities of visualization in view of the potential of digital media. The process to re-read the digitized artworks by Vasarely was started in the Rhinoceros software, along with the Grasshopper plugin. From there, it was possible to establish parameters to reinterpret the original artwork taking into account the RGB channels of the digitized work. The steps below were common to the three recoding processes for the three images: the reparametrization of a plan; the division of this plan into points, and, consequently, the simulation of sculptural forms taking the RGB channel filter as a conversion parameter. For each of the three images, we used the image sampler3 component of Grasshopper, which enables the reading of information from the image’s colour channels. After the creation of the parametric modelling pieces, we used the subtractive process to thin them through a CNC4 milling machine, and as raw materials the MDF (Valchromat) 1
This work was only possible due to the cooperation with the Laboratory of Models and Assays of FAUUSP and the Fab Lab São Paulo, which provided the space, technical support and machines for execution of the works. 2
We can categorize digital fabrication based on the way objects are produced. And, in this sense, we can admit three types of processes: subtractive (thinning of material), additive (addition of material) and formative (deformation of material). 3
According to the help menu of the component, the image sampler allows for evaluation of pixel data stored in image files. By default, the image sampler is updated whenever the base image changes, so it is not necessary to retake all steps of parametrization upon loading the other two images. 4
The numeric control milling machine used thins a material in the X, Y and Z axes.
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plates superposed. At the end of the process, three plates were fabricated, each one representing a reinterpretation, a recoding of a painting by Vasarely. In sum, these artistic experiments were generated from the numerical simulation of the geometric structure of the Op Art pieces, transposed to a three-dimensional support. By associating the numerical simulation processes to methods of prototyping and digital fabrication, we enable the representation of complex data, given the accuracy involved in the media transpositions process. Not only was it possible to model complex elements, whose manual construction would be unfeasible, but their exact physical representation also became conceivable. According to Pupo (2009: 5), the complexity reached by digital models is owed to the “three-dimensional software based on Non-Uniform Rational BSplines (NURBS), which offer parametric surfaces and curves” necessary to the development of difficult forms. For each of the experiments conducted, the proposed poetic guideline was the recoding of Vassarely’s artworks having as parameter the intensity variations of each colour channel as the foundation to obtain the three-dimensional representation. The potentials of digital media have allied to creative intentions as a way to get to new inventions. The translations made presented a path that goes from colour to volume, from two to three dimensions, from numeric to analogue. The results generated portray ways of creating, moulded by the intention of the authors, but which at the same time are amplified by the programming logics of the computer. This machine behaviour of analyzing the cultural world extracting “analogue models” and turning them into “operatory” is configured as “cybernetic”, and this is a heuristic creation method which, according to Plaza and Tavares (1998: 93), is based on the “synergy of functions between [man and machine]”. This artistic experiments also presents characteristics of the heuristic project method, by assuming as operative direction the obtainment of pre-established steps, but which are necessarily reviewed on the basis of the materialities of the media used. Once creating based on projects “happenings are generated through structures”, the material potentialities of the new media “install qualitative and orderly structures that enable the construction of the mental insight”. Another heuristic method present in the creative path of artistic experimentation is the recoding method. In this case, the analogy reasoning led the artists to rework the poetic effects of Vassarely’s pieces, so as to extract from them new points of views, using digital fabrication to that end. This second degree creation starts from a situation and restructures it “according to other symbols, integrated in a different order, evidencing other connections”. This representation of the representation results in a “method of creation from other signs”, giving rise, according to Plaza (1987: 40), to virtual qualities, appearances that never happened before. As refers to the material x (i)mmaterial dialectics, the interfaces used by the artists establish themselves as operators of contact and translation, allowing possibilities of articulation between the analogue and digital universes. By resulting from the translation between codes, the printed physical model stresses the expressive and synesthetic character embedded into artists’ proposals. As we know, based on Tavares (2001: 129-130), it is the transformation between immaterial and material, performed by transducer devices, which ensures that the image is updated under different configurations, from the transit between softcopy and hardcopy. The objects resulting from the recoding derive from the numerical simulation of geometric structures generated from the transcoding of the RGB channels values in Vassarely’s artworks, and such structures gain a physical appearance with the help of digital fabrication equipment that reproduce digital into physical material.
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3. CONCLUSIONS The intention to use computer as a metamedium to process the data from a digital image, and then proposing parameters for the development of syntactic rules for the construction of three-dimensional forms is the poetic guideline that sustains the artists proposal. The digital image was manipulated so as to use its light source colour values as the means to create volumetry. The colour turned to be evaluated in a way detached from its original constitution and materiality. The subsequent fabrication of the pieces with the help of the numerical control milling machine enabled to physically materialize the object, bringing it to appearance through the recoding of the digital parameters of colour as a light source into volume. From the translation of analogue into digital and vice-versa, the artistic object could be replicated, recreated and moulded. What we realized from this case study investigated was the possibility of using an automated production method as a creative enhancer in the search for new forms of expression. Methods originally conceived for industrial production purposes are now used for a new language of artistic and innovative character. The possibility of modifying the machine programming and then reaching new results that achieve customization, not only serial production, results in creative gains for the arts. The artist uses automated production technology in favour of gains in his creative potential. REFERENCES Plaza, J., and M. Tavares. 1998. Processos Criativos com os Meios Eletrônicos: Poéticas Digitais. São Paulo: Editora Hucitec. Plaza, J. 1987. Tradução Intersemiótica. São Paulo: Persperctiva. Pupo, R. 2009. Inserção da Prototipagem e Fabricação Digitais no processo de projeto: um novo desafio para o ensino da arquitetura, Campinas: FEC. Doctoral thesis available online, http://cutter.unicamp.br/document/?code=000442574. Tavares, M. B. S. 2000. A recepção no contexto das poéticas interativas. São Paulo: ECA/USP. Printed version available at the ECA-USP library. Vasarely, V. 1973. Victor Vasarely: Planetary Folklore. München: Bruckmann. Address: Juliana Harrison Henno, Department of Visual Arts (CAP), School of Communication and Arts, University of São Paulo, Av. Prof. Lúcio Martins Rodrigues,443, Cidade Universitária, São Paulo, Brazil E-mails: julianaharrison@usp.br, mbstavares@usp.br, henristabile@gmail.com
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