COLOUR-CORRECT 3D COMPUTER PRESENTATION OF THE MASTERS' HOUSE KANDINSKY-KLEE Harald Fleischer, Klaus-Jürgen Simon, Hartmut Ziemann Hochschule Anhalt (FH), PF 2215, 06818 Dessau, Germany, [email protected]

KEY WORDS: Architecture, History, CAD, Colour, Photo-realism ABSTRACT: The paper describes the process of creating from provided survey results a three-dimensional digital model of the master house Kandinsky-Klee in wire-frame fashion using the programs Cinema. The Kandinsky half of the master house was rendered for two particular points in time using the colours determined by restaurateurs and coded in the Natural Colour System. KURZFASSUNG: Der Bericht beschreibt die Erzeugung eines dreidimensionalen digitalen Drahtkastenmodells des Meisterhauses Kandinsky-Klee unter Verwendung vorliegender Vermessungsergebnisse. Die Kandinsky-Hälfte des Gebäudes wurde für zwei verschiedene Zeitpunkte gestaltet. Dabei fanden die von den Restauratoren im Natürlichen Farbsystem bestimmten Farbgebungen Verwendung.

1 INTRODUCTION The Dessau homes of the painters Wassily Kandinsky and Paul Klee during their time as Bauhaus teachers between 1926 and 1932 were reopened to the public in the year 2000 after extensive restoration. The original colour scheme of the double house of Kandinsky and Klee appears to be selected by Gropius. The two painters modified the colouring scheme within their houses almost continuously during their time of residency using more than 350 shades. The unconventional and massively differentiated colour scheme is, in its variety, unique within modern architecture. The building was renovated to reflect the state when the painters left the buildings and Dessau. Since the data were available, the computer presentation of the Kandinsky part of the building was rendered not only for the renovated state but also using the original colour scheme. The colour data coded using the Natural Colour System were used to prepare an animation for several rooms, and the user could at any time during the animation toggle between the two different colour renditions.

2 HISTORIC BACKGROUND Between 1919 and 1933, the Bauhaus School, based first in Weimar and then in Dessau, revolutionized the architectural and aesthetic concepts and practices inherited from the Renaissance. The buildings put up and decorated by the school's professors (Walter Gropius, Hannes Meyer, Laszlo Moholy-Nagy or Wassily Kandinsky) launched the Modern Movement which has shaped much of the architecture of the 20th century. Director of the school was from 1919 to 1928 Walter Gropius, a German architect and educator who exerted a major influence on the development of modern architecture. In Dessau, Gropius designed the school building and faculty housing (1925-26) at a time when Gropius was possibly at the peak of his creative powers.. The school building itself is a key monument of modern architecture and Gropius' best-known building. Its dynamic composition, asymmetrical plan, smooth white

walls set with horizontal windows, and flat roof are features associated with the so-called International Style of the 1920s. The faculty housing comprises a small estate of 3 semidetached houses for the Bauhaus Masters and one detached house for the Bauhaus director. These houses called "Masters' Houses" were living quarters and studios for the permanent Bauhaus teachers, or "Masters", as they were known. In August 1926, even before the opening of the Bauhaus, Walter Gropius and his Masters Lazlo Moholy-Nagy, Lionel Feininger, Georg Muche, Oskar Schlemmer, Wassily Kandinsky and Paul Klee moved into the houses. The residents were no longer permitted to enter the houses after the nazis closed the Bauhaus in 1932, and the houses were first used as residential buildings by the city and in 1939 sold to the Junkers factory belonging after an expropriation to the state. The houses were modified significantly in their structure in order that they would better meet the new requirements. During World War II, the Director's detached house was destroyed as was one side of the neighbouring semi-detached pair. Since 1945 they are again property of the city of Dessau. The renovation of the buildings occurred in stages: - the Feiniger half of the Masters'House MoholyNagy−Feiniger was restored in 1994; the other half was completely destroyed, - the Masters' House Kandinsky-Klee was restored in 1998/2000, - the Masters' House Muche-Schlemmer was restored in 2000/2002. In 1999 the Masters' Houses, like the Bauhaus building, were placed on the UNESCO World Cultural Heritage list.

3 THE BUILDING AND ITS CONSTRUCTION The Masters' Houses appear like an assembly of cubic elements. The horizontal positioning of these elements is enhanced by balconies (fig.1). Vertical windows in the staircases extending over both storeys accentuate further the basic appearance of the building; these windows are not visible in fig. 1 The outer shell of the three double houses is practically identical. It was constructed from survey data provided by a consulting company involved with the renovation of the buildings, using a Windows version of Cinema 4D XL v5, a program available at the department of design at the school. Additional surveys were needed to better define details whenever the construction failed based on the provided data only. The steps of construction were: - construction of a wire-frame model (fig.s 2 and 4), - selection and application of surface materials and characteristics, and - selection and application of the illumination including the day of the year and the time of the day (fig. 3). The interior of the Masters' House Kandinsky-Klee is surprising because of the many fittings retained in their original state, such as windows, doors, hinges, built-in cupboards and floor coverings. An effort was made to present these exact in order that one could zoom in on them, for example on a door to open it.

located on the north side of the building), - construction of the original (Gropius) colours (fig. 8, following page) and - application of the colours at the time Kandinsky had to leave the building (fig. 9, following page). In order to appreciate the in times rather striking changes in the room colours, two additional rooms are shown with "Gropius" and "Kandinsky" colours on the last page of this paper. Cinema allows the computation of animated sequences. Since Cinema is not available at the department, 3D Studio MAX will be attempted in the near future using data constructed in AutoCAD.

Fig. 1 Masters' House Kandinsky-Klee from southeast

Because the surveying department of the school uses AutoCAD and 3D Studio MAX, the building is at present reconstructed in AutoCAD as part of a diploma thesis. Large data volumes and time constraints made it impossible to continue the work for the entire building. Since the work was started on initiation of the director of the Anhalt Art Gallery who wanted a tool to investigate colour schemes for single rooms, the work continued for single rooms at a time. Therefore, one of the rooms will now be presented in six stages: - construction of a wire-frame model (fig. 4, following page), - application of surface materials (fig. 5, following page), - application of illumination from the ceiling of the room (fig. 6, following page), - application of outside illumination (fig. 7, the position of the illuminating light source was chosen arbitrarily to demonstrate the effect for a room

Fig. 2 Masters' House Kandinsky-Klee from southeast – wire frame

Fig. 3 Masters' House Kandinsky-Klee from southeast

Fig. 4 Wire-frame section of the Kandinsky house

Fig. 6 The room from fig. 5 with ceiling illumination

Fig. 8 The room from fig. 6, Gropius' colours

Fig. 5 The room from fig.4 after rendering

Fig. 7 The room from fig. 5 with outside illumination

Fig. 9 The room from fig. 7, Kandinskys colours

4 THE NATURAL COLOUR SYSTEM The Natural Colour System (NCS) is a colour coding system based on a human observers' ability to determine the appearance of a colour using the four chromatic base colours red, green, blue and yellow, and the two achromatic base colours black and white. It is a Swedish national standard and might have been selected as an international (ISO, CIE) standard if it would have had a personal copyright attached to it.. NCS can be used to define all surface colours and give them a unique designation. All imaginable surface colours find a position within a three-dimensional model in the form of a double-cone (fig. 10).

Fig. 10 The NCS Colour Space

The double-cone space is presented as a circular base with a colour at every 9° (fig. 11,) and as equilateral colour triangles (fig. 12) for each colour included into the colour circle. The NCS colour circle shows how the four elementary colours can be used to create other colours: the circumference is divided into four quadrants, and new colours are mixtures of the two elementary colours on either end of the quadrant. Colours situated opposite each other (red/green and blue/yellow) are mutually exclusive, and each hue is a mixture of only two elementary chromatic colours. All colours of the same hue are presented in a colour triangle having a grey scale as axis between the two poles white and black. The distance from the axis indicates the saturation of a colour. The NCS colour space is available for implementation under image processing software like PhotoShop based on the Euroskala, a European standard for 4-colour printing. It appears on the monitor in the form a series of colour triangles for different hues (fig. 13). Each triangle contains fields with colours of known NCS designation. The user can use these triangles to select colours by visually comparing the appearance of the designated field with the appearance of a colour defined by the colour management system of the software used. Colours given with their NCS code can therefore be selected and assigned to surfaces as needed. The interior of the Masters' House Kandinsky-Klee is not only noteworthy because of the airy spacious studios, the staircase windows and the many fittings but also because of its interior decoration using many unique colours. This unconventional and massively differentiated colour scheme is, in its variety, unique within modern architecture.

Fig. 11 The NCS Circular Base

Gropius appears to have been responsible for the original colouring scheme of the Kandinsky house, Kandinsky modified it almost continuously during his time of residency using many shades, mostly differing from wall to wall. The restaurateurs determined all found colour shades using NCS, hence, surface colours could be assigned using the NCS computer implementation. The building was renovated to reflect the state when the painters were forced to leave the buildings and Dessau after the dissolution of the Bauhaus. The computer presentation of the Masters' Houses Kandinsky-Klee was initiated by the director of the Anhalt Art Gallery. He hoped to obtain a tool to investigate rooms in regard to colour harmonies since only the sequence of colours but not the dates of application could be determined. This goal was later reduced to a comparison of wall colours for the time of first occupation and the time of expulsion. The head of the cultural department of the city of Dessau desired to obtain a mouse-controlled animation allowing the selection of any room and the change of viewing direction within the room interactively. Time constraints did not allow the implementation of his ideas. The construction company restoring the building largely at own expense desired a animated tour through the building – one wall originally separating the two semi-

Fig. 12 One of the NCS Colour Triangles detached houses was removed to facilitate the later use of the building as a museum – to be presented on a single CD purchasable by visitors. This goal could not be reached because of the enormous amount of data. Several months were available to work on the project. Part of the time with for familiarization with Cinema which was to be used in the project. Initially, two rooms only and the atelier in the Kandinsky house could still be after completion of the outer shell. The animation presented either room; the operator was able to stop the flow of the Fig. 13 animated sequence at any time by mouse click, change from one to the other presentation using a provided toggle switch and continue by mouse click. This first animation required approximately 500 MB of data and a Macintosh G4 computer provided by the city of Dessau to run. In

order to be able to present true colours on the monitor a Barco Calibrator which has a sensor for the colour temperature of the room illumination and is therefore able to adapt to changes in illumination, was used. In order to be able to use some of the results on a PS using Windows, a PowerPoint presentation was prepared. This presentation showed different views of the completed rooms in the two different colourings. A further PowerPoint presentation was prepared recently for an exhibit prepared for the opening of the recently restored Masters' House Muche-Schlemmer. It runs continuously for approximately seven minutes and includes five slides comparing different rooms with present-day colouring as still images and with the initial colouring as an animated sequence assuming a stationary observer scanning full circle. Each animated se-

quence was prepared in Cinema 4D XL v5, requires approximately 0.3 GB of data and runs 24 seconds 6 CONCLUSION Although some spectacular results were achieved on this and other projects much work remains to be done. One of the encountered problems is the need to find a way to compress true-colour data without any effect on the colour rendition. Other problems are for example the development of a meaningful script for an intended animation and the inclusion of interactive elements into an animation. More information on the Masters' Houses can be found under http://www.meisterhaeuser.de and on the NCS http://www.colorsystem.com or under under http://www.ncscolour.com .