SURFACE MODIFICATIONS

Post 647 -by Gautam Shah

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Natural and Industrially-produced materials require some form of surface modifications or treatments, before being put to functional use, or for readying them for the next process. Surface modification at a basic stage, consist of cleaning and mechanical scrubbing. The surface modifications are for creating use-worthiness by levelling, texturizing, or for application of additional materials for shielding. The surface modification starts with visual observation and touch-feel experience that no foreign materials have remained on the surface, and all loose (removable) materials are removed. These simple processes ensure integrity of the surface.

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The next level of surface modifications are applications like coating, physical-chemical treatments, cladding, mounting, plating, joining, welding, levelling, cleaning, washing, ph balancing, static removal, etc. Surface modifications are intently surface preparation processes and may impart radically different surface qualities such as textures, ionization, etc.

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At another level Surfaces Modifications are not attempted, but such situations are negotiated with technologies. These include defining means to override the hindrances of texture, handling issues, electrical and other properties. These technologies also include forming shields around the users, tools and other equipments rather then over objects. The shields are physical layers and non-physical arrangements like restricting the exposure through time-space management.

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In early ages, the surface modification and applications were an integrated process for exploiting the surface of any object. Primitive arts and crafts had a comprehensive treatment that consisted of 1: Modification of the surface, 2: Application of surface forming materials, and 3: Rendering new textures and tonal variations or shades. At a later stage an additional treatments for protection of the new surface were devised.

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Surface modifications are physical, chemical and mechanical processes.

The Physical processes are mainly used to remove unwanted particles or materials (such as rust, nodules, residual deposits, dust or grease, lubricants, cutting-oils, etc.) adhering to the surface. Rubbing, air-dusting, vacuum cleaning, wiping, water-bathing, etc. remove such adhered materials. The particles have remained on the surface due to the holding by surface texture, bonding or ion attraction, and horizontal storage. Washing with soap or a surface active agent (surfactant) can weaken the ion attraction break the weak molecular bond generate by-products that can be removed easily.

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The Chemical processes include acid-alkali treatments and solvent washing. The processes roughen, etch or smoothen the surface. In many instances the resultant by-product is beneficial or neutral, and so allowed to remain on the surface. In other instances a secondary treatment is required just to remove the by-products of the first treatment. Sometimes Surface preparation agents themselves are the primary surface finishes. Such agents cover the surface area as an intermediary film. Such films help in bonding of the final surface finish. Chemical processes also include burnishing, flame-treatments, surface annealing and hardening, cathodic modification, sputtering and material’s depositions.640px-A_brass_utensil

The Mechanical Processes affect the surface superficially. Cleaning of the surface by removal processes include abrading, grinding, rubbing, blasting, planning, chipping, etc. Other mechanical processes alter the surface with newer textures by engraving, patterning, planning, surface deformation, etc.

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Surface modifications processes have been used for body painting, pottery, home building, agriculture, mural or wall artwork, adornments, jewellery, ornamentation, household utilities, tools, musical instruments, etc. Surface modifications were explored pattern making, texture creation, personalization, cultural expression, totem, abstract or symbolic representation etc.

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Surface levelling is achieved by scrubbing or rubbing off the impurities, removing select protruding sections, or by skinning the entire surface area. In later cases there are chances of removing a seasoned or matured face and exposing a fresh one. Partial scrapping of the surface creates qualitatively unequal zones. This is the reason why over the ages levelling ‘plasters’ have been preferred. The ‘plasters’ can be thin coating, or an application of thicker mass. These were often rendered with patterns and textures or ‘loaded’ with minerals and colourants. Wet surfaces were, either, engraved or embossed with patterns to encourage the penetration of colours, to produce a bas or relief effect, or provide a highlighting boundary to the drawn object. Colours were blown as dry powders or applied as pastes and dabbed (pressed) into the wet plaster.

Gesso, a mixture of plaster of Paris (or gypsum) with size, is the traditional ground. The first layer is of gesso -grosso, a mixture of coarse, un-slaked plaster and size. This provides a rough, absorbent surface for ten or more thin coats of gesso sotile, a smooth mixture of size and fine plaster previously slaked in water to retard drying. This labourious preparation, however, results in an opaque, brilliant white, light-reflecting surface, similar in texture to hard, flat icing sugar.

Other related Blogs

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PAPER as a SHEET MATERIAL

Post 646 –by Gautam Shah

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Paper is a sheet form of material, and substantially used in sheet-form. Paper’s chief raw material is cellulosic pulp. It is also used in ‘non-planer’ forms, such as moulded products (egg crates), packing cases (glass), mould dummies, and as Papier-mâché.

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Paper pulp egg Cartons Wikipedia Image by Edward Betts

Paper as a sheet material is available with many different properties. It can be rough, smooth, grease-proof, water absorbent, water repellent or resistant, soft as cotton, stiff as board, heat resistant, fireproof, combustible, chemically resistant opaque, translucent, transparent, coloured, glossy, dull, strong, weak, tear-able, non-tear-able, light heavy, pulp-able cellular, waxed, sanded, embossed hinged corrugated, easily folded and pierced, coarse, fine or flocked.

Paper is mainly used for writing, printing, drawing, painting signs and images. Paper has many functional uses like wrapping, filtering, absorbing, insulating, protecting (Thai umbrellas), cleaning, mopping, polishing, buffing, toys and product forming, mould making, engraving, etching, embossing, medicare dressing, garment making, and for glazing (Shoji for windows and Fusuma for room dividers). Other uses include mask making, light canoe or boat making for races, single-use construction forms, casting die dummies, kites, lanterns carnival floats, tubes, textile bobbins and cones.

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Pen box of Papier Mache with Oil coating Iran 1694 (Now in AK Museum Canada)

Paper pulp is used in various sheet form composites. Fiber boards are products engineered at a pulp stage. Various products differ in terms of nature and level of ‘pulping’, pressing technologies (pressure, temperature, curing used), wet or dry process of manufacturing, additives (both filler and bonding) and surface treatments. The products include high-medium-low density boards (typically MDF), hardboard, ‘Masonite’ boards, pulp boards with gypsum, cement and other minerals, natural and synthetic fibre additives. These sheet materials are surface treated, coated, tempered, laminated, co-formed or co-extruded.

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Parchment Paper > Pixabay image by Geralt

Inferior plant materials and timber wastes are partly pulped to form a homogeneous mass. Such partly pulped mass, however lack the mutual particle bonding. Boards (and often pre-shaped forms) are created by steam-pressing and with aid of 5% bonding materials (typically Urea or Phenol formaldehyde). Portland cement, Gypsum and polymer emulsion adhesives are also used for forming building boards. Paper pulp boards of extreme light mass are coated with Gypsum, polymers and foam to form acoustic ceiling panels. Layered paper composites with phenolic compounds are used as circuit boards and electric insulation panels.

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Paper making in Hahnemuhle > Wikipedia image by Hahnemuhle PR 

 

Structure of paper as sheet material differs from other sheet materials:

  1. Papers unlike plastic films and metal films are fibrous.
  2. Paper is composed of single short fibres, arranged largely at random instead of a regular array as is the case with woven fabrics.
  3. Unlike cloth, felt or leather it is laminar, that is each fibre is disposed mainly in the plane of the sheet.

Paper, however, resembles other sheet materials in that its structure is anisotropic in its plane and most of the fibres are oriented along the grain or the machine direction.

Paper is mostly made from cellulosic fibres derived from plant sources. The fibres depending on their origin have different types of cell structures, and so provide unique character to the paper. Cellulosic fibres are hygroscopic and swell considerably when wetted, but retain strength and durability. Most plant materials also contain non-fibrous elements or cells. These are less desirable for the paper making, but are useful as a filler material. Until about 19 C. paper was produced by hand processes, and as a result had very distinctive local style, texture and properties. Through the 18th C the paper making process remained essentially unchanged. The linen and cotton rags were the basic raw materials, but increasing demand for paper was posing shortage of pulp raw materials.

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Packaging forms with Papier Mache > Wikipedia images by Berklas

Paper is manufactured from material resources that can be regenerated, and the product is a recyclable material. Major sources of cellulosic fibres for paper manufacturing are wood and cotton. Cotton fibres are used in the form of lints (seed hair left behind after ginning), staples, waste yarn and threads and rags. Lints require no processing, staples need length shortening, but yarns, threads and rags need undoing of all mechanical processes such as spinning and weaving. Cotton fibres offer strength, durability, permanence, fine formation, colour, texture, and feel.

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Modular ceiling Panels of Paper Pulp > Wikipedia image by Adamantios

Wood pulp has been the chief material for paper making, but where forest resources were scant, many alternative sources have been explored. These sources include: Cereal straws, plant stems, linen, jute, hemp, bamboo, cane (rattan), paddy (rice) straws, banana leaf, sugar cane waste bagasse and grasses like esparto. Paper made from such alternative pulps, and without an admixture of other fibre tend to be dense and stiff, with low tear resistance and low opacity. Often such fibres are desired as additives for producing paper for abrasives (sand-paper), cover stock and heavy-duty industrial papers. Such fibres are also used for strength in duplicating and manifold papers. Flax is grown expressly for high-grade cigarette paper.

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Synthetics: Paper like sheets > (https://pixabay.com/en/paper-colorful-color-school-paint-182220/) Image by AlexanderStein

Synthetic or man-made fibres provide certain advantage when compared to plant based materials for paper pulp. Natural cellulose fibres vary considerably in size and shape, whereas synthetic fibres can be made uniform and of selected length and diameter. Long fibres, for example, are necessary in producing strong, durable papers. There are limitations, however, to the length of synthetic fibres that may be formed from suspension in water because of their tendency to tangle and to rope together. Even so, papers have been made experimentally with fibres several times longer than those typical of wood pulp, and these papers have improved strength and softness properties. Natural cellulose fibres have limited resistance to chemical attack and exposure to heat. For such purposes synthetic fibre papers can be made resistant to strong acids, for example in chemical filtration. Paper can even be made from glass fibre, and such paper have great resistance to both the heat and chemicals.

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Golf ball rest pins of dissoluble wood Pulp (http://maxpixel.freegreatpicture.com/Golfing-Tee-Golf-Golfer-880532)

Rags (mainly of cotton) are used extensively where permanence is of prime importance such as for bank notes, legal documents and security certificates. Technical papers include tracing papers, vellums, and reproduction papers, high-grade bond letterheads, cigarettes, carbon, and Bible papers. Khadi (Indian hand made) paper is an example of high rag content paper.

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Rags sorting for paper making > Image by Lewis Hine (1874-1940)

Wastepaper is a major source for cellulose. By recycling the wastepaper the dependency for virgin fibre is reduced and the problem of solid waste disposal is minimized. However the difficulties like, gathering wastepaper from scattered sources, sorting mixed papers, and recovering the fibre from many types of coated and treated papers, make it a very complex problem. Waste Paper treatments for asphalt, synthetic adhesives, metal foils, plastic and cellulose-derivative films and coatings, printing inks, etc. pose acute problems in reuse of paper wastes. Wastepaper is of four main categories: High-grade, old corrugated boxes, printed news papers, and mixed paper. High-grades and corrugated stocks originate mainly in mercantile and industrial establishments. White paper wastes accumulate in paper conversion units and printing plants. Magazine stock comes from newsstand returns, but some comes from homes. Mixed papers come from collectors. Grey Board, cardboard or Packing carton papers are produced from recycled paper wastes. These are as single or multiply boards.

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Laminated-multi-layered paper products > Wikipedia image by Veganbaking.net from USA

In recent years Papers have been coated, layered or co-extruded with many other forms of sheets, films and membranes. These include, metal foils, polymer films, metalized polymer films, films formed through liquid coatings, in-situ foam forming.

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REUSE of BUILDINGS

Post 645 –by Gautam Shah

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Buildings continue to be relevant for many different reasons. Buildings persist, primarily by changing the functions they serve, secondly by redefining the form, and in rare cases, by altering the surroundings. Buildings are continued by Enabling interventions and Restorative actions. Re-use is a process of re-endowing value to neglected built-forms, which otherwise could see demotion.

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Turbine Hall of Bank side Power House Wikipedia image by Cwrcun

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Tate Hall (original turbine machine room)

A building and its lands, both are precious assets. Buildings are acquired at a great expense of resources, effort and time whereas the lands, now have new relevance being in central location and good connections. No one wants, either to go wastes. Buildings and the lands must be put to different use. Reuse strategies relate to establishing the lands and building for a ‘purpose other than the original one.

Location is the external realm of the building. It has two facets: the distance or the extent and the stack holders of the building. A building serves certain terrain or physical distance. When these get enlarged due to efficient transport services the usage is increased, but conversely barriers like railway tracks, canals, closure of roads, or loss of visual identity affects the raison d’ etre (reason for existence) of the building. Stack holders become insincere for maintenance when the location begins to deteriorate due to economic, social or political problems, and affects the pride or faith in the building.

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Batter sea Power House Station Building being  redeveloped with specific conditions like preservation of four chimney structures > Wikipedia image by > Attribution Nigel Cox

Lands become available for reuse, due to the changes in land zone and occupation patterns, such as residential to commercial or industrial to residential. Lands need re-validation of purpose when new developments like location of an airport, highways, railway tracks, etc. take place in neighbourhoods. Existing lands have an advantage of location and connections.

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Arnold Print Works as seen from Marshall street in North Adams, Massachusetts> Wikipedia image by Beyond My Ken

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Main Entrance Massachusetts Museum of Contemporary Art (MassMoCA) Wikipedia image by Beyond My Ken

Reuse of lands and built spaces is a form of urban rejuvenation, rationalization of urban density and strategy for sustainable use of resources. Reuse, sometimes deals with issues of conservation and so considered by some, as ‘compromise between historic preservation and demolition’.

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One of the Reuse project by Gasometer City, Vienna, Austria. Four disused gasometers were revamped into residential quarters > Wikipedia image by (Andreas Poeschek by CC-BY-SA-2.0-at)

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Internal Courtyard of Gasometer at Vienna > Wikipedia Image by Andreas.poeschek by CC-BY-SA-2,0-at

To use a building for a different purpose, many corrective actions are required. Redefining the form of a building is difficult as it is expected to satisfy, simultaneously, the functional needs and the value system in the society. In the first instance if the owner finds the corrective actions uneconomic, would rather opt for a new entity. In the later case, the changes in the form may make the society apathetic to the building’s revised ‘look’. Often, the cost of renovation, rehabilitation or restorations, are more costly than demolition or building newly.

The preservation of surroundings of buildings requires social, political and financial involvement, which are beyond the reach of the owner or user. It is only for buildings intensively serving social functions or buildings with historical connections that surroundings will be conserved or even redefined. A building, if is a public utility or society’s pride and prestige, its surroundings will be maintained or even resurrected. Changes in the surroundings force functional changes in the building, however, whether one makes the changes to be with surroundings or resists, both ways the building gets altered.

Old buildings become unsuitable for their conceived requirements with passage of time. The building’s own technological validity (of service systems’ and components’), and the circumstantial relevance of the planned usage, both, change, and independently. To these, political conditions and financial consideration (benefit accruing out of it) complicate the assessment.

A building, if it has a form of architectural styling then it is continued as a relic. When it has commemorative connections, in appreciation of its past, the building becomes a monument. Buildings that need to be remembered are restored or preserved to retain their form, but often in complete absence of the original setting. A building that has substantially lost the form and has indistinct connections can be enacted through re-imaging of its setting, like through Sound & light (son et Lumiere) shows on historical sites.

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Reused Pillars for Arcade at Adhai Din Ka Zonpada India > Wikipedia image by Billyakhtar

A building as a built-form stays till the structure or parts of it can provide shelter. And even after the loss of its integrity as a shell for shelter, its parts and components are scavenged for reuse. Romans and many others have used refuse in their new constructions. There are unknown costs in managing debris of old buildings, related to handling materials like glass wool, asbestos, and radio active contaminants, and demolition and removal of materials from dense localities.

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Asbestos and Lead paints require specific care for removal

Older buildings need substantial review of their functions, due to changes in ownership, reassessment of efficiency, styling and context. As the buildings age, the nominal surface related changes go deeper into the body of structure. Such changes are not easily perceptible, and can grow to very dangerous level. This is a stage when original design documents are not available. The new technology components and systems may not match the existing provisions. Repairs and maintenance schedules can restore parts, components and systems, provided the design is ‘open-ended’. However, holistic creations or ‘close-ended’ entities deteriorate completely without any scope for corrective measures.

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SPATIAL NATURE of WINDOWS

Post 644 –by Gautam Shah

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Windows are surface elements with great presence on both exterior and interior sides. It is fairly a complex entity against the comparatively simplistic wall, but a surface that is penetrable. Its surface is very dynamic, due to the continuous variations in views through it and the vivid reflections on the glass surface. The contextual conditions like climate, illumination, distance and angle of observation and the purpose of use and multifarious position of the shutters continuously reshape the perceived form of the window.

The external changes are reflected as a reverse mirror image in the glazing surface, and the interiors get revealed through an iridescent surface. A window, as a single picture frame, simultaneously reveals the changes occurring in the interiors as well as exteriors. The dynamism of the window gets enhanced further by the framing, masking and filtration of the perception.

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Looking out Chand Baori Stepwell Rajasthan India Flickr Image > https://flickr.com/photos/bpprice/12043141995

A window is like a membrane with degrees of permeability. It may not permit one to go through it, but allows to stretch out through the sensorial faculties. We see, smell, listen and feel the other side through the window. The connection to the other side of the window is always short and casual. The frugal experience stimulates one to go across it, albeit by other means. Doors are dilemmas, either go out or remain in, but a window provides no such options. A person on outside of a window perceives the safety in the interior, and the one in a bounded space realizes the freedom and diversity of experiences available outside. Windows have been used for opening out the interior spaces or for bringing in the exteriors.

Pecs Zsolnay Architectural District Building

The historical window with opaque glazing of heavily coloured pot glass was extremely colourful but dead static. As the glass became thinner and lighter in colour, the changes in outside levels of illumination began to be noticed on the interior face. This was aided by the use of water white Cristallo glass. Interiors seemed now much more natural, and attuned to the outside changes in luminescence. Till 19th C windows were vivid elements in an otherwise static exterior or interior surface. The Cristallo glass, outside was a dull metal like an opalescent surface, but new clear glass with better casting, polishing and fire finishing began to be iridescent.

The glass was recognized as having two distinctly different faces. Iridescent on the outside face due to reflections and a ‘water-white’ flawlessly clear and non glossy surface on the interior face. Corbusier used the opaque iridescence of the exterior surface to juxtapose the exterior masonry or cement surfaces. But FLW used the deep shadows to eliminate the exterior iridescence and added colour staining and patterning to break the transparency. Mies used the exterior mirror like gloss to reflect the changes occurring in the surroundings concurrently juxtaposing the interiors. This helped to reduce the massiveness of the built-form.

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FLW Window with masking of Pattern > Flickr Image by Hardisty

Window glass is now often used to assimilate the realities of interior and exterior on a very large joint-less screen. The mix creates a very vivid object, like a water body reflecting both the sky and the floor. Metalized opaque glass belies the two-way transparency of a see-through element.

Wall to wall glass openings dissolve one or many sides of a volumetric space, reshaping its perceptive size, scale and extent. The spatial illusion becomes more intriguing when such a large reflective glass surface is used. Wall corners, large stretches of surfaces, acutely angled spaces, stubborn elements like columns and piers are dissolved by illusion of windows through mirroring effect of glass.

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Corner in Glass > Flickr image by Wonderlane > https://www.flickr.com/photos/wonderlane/4889566212

We are conditioned to expect certain spatial effects in a space. And glass is an effective tool for breaking that anticipation. A narrow space visually gets widened by a glass opening. Skylights and clerestories add ‘lightness’ to the space. Lights such as roof holes focus the attention. Openings, depending on their location and nature redefine the space configuration. The stratification of view to the outside offers different scale to the space. Significantly bright areas highlight the details, and so are perceived and registered, more effectively then darker zones. A window becomes an element for changing a space, intentionally and accidentally.

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Madrid Crystal Glass palace Pixabay image by IvanPais Espanol

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Madrid crystal glass palace > Pixabay image by IvanPais Espanol

Windows are furrowed gaps into an otherwise solid barricading mass. The depth is highlighted due to the dark interior, and shadows cast by strong and directional light. The shadows as a form creating element was very well exploited by L. Kahn in his Asian buildings. The same effect at a micro scale and in repetition creates a lattice, used in Indian Architecture. Windows like, bay, bow, Mashrabiya and oriel have been used to enlarge interior spaces and also to correct the interior shape of the space. Zarokhas add to the interior space but have also been used to undulate the exteriors.

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Gothic window tracery Snettisham Norfolk England > Flickr Image by Spencer Means > https://flickr.com/photos/hunky_punk/7511302668

Masking has been very commonly used to change the character of the windows. Greek and Roman architecture subdued the openings as a secondary and less visible layer. Romanesque windows once again came to the surface, but openings were framed by the semi circular arch. Coordinating several windows was a difficult design issue, as the height of the rounded arch was defined by the width of the opening. Gothic architecture solved the problems of geometric composition, by of pointed arch. It also created a system of subdividing the window opening through mullions, transoms and glazing bars. The window opening was masked by traceried patterns. Window masking became an effective tool to overcome the deficiencies of glass, size, clarity and impurities. The deficiencies made the windows subservient entity of the load-bearing structure. Glass houses, orangeries, etc. allowed windows to define a space without the use of a wall. The need for very large and deep sun lit spaces for bus depots, railway stations, markets, and factories redefined the Windows’ spatial nature.

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Pot Metal Glass stained Window Exhibit in Krannert Art Museum > Wikipedia Image

Framing is a property of all openings. Openings have their sides and mid members within the view cone depending on the point of observation. Palladio masked and framed the exterior face of the opening. The double-hung sash windows did the same on both, exterior and interior face. Framing is now used as an inevitable joint management system, and but often made imperceptible. Stratification (window openings’ position @ low, mid or higher level with reference to height of the user or the task plane) is an important ergonomic parameter that affects the spatial perception.

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Elgin Cathedral > Wikipedia image by Billreid

Transparency is a quality of the glass, and the most important aspect of the surface of the opening. A window opening in the form of a glass curtain wall or shop front, shows up the space in its exterior surface configuration, and also the spatial depths of its interiors. The simultaneity of the exterior and interior spaces adds to the dilemma of the physical reality vs the virtual reality.

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Glass house by Philip Johnson New Cannan, CT USA > Wikipedia image by Staib

This re-composed article is based on my earlier BLOG > here >

http://talking-interior-design.blogspot.in/2009/12/spatial-character-of-windows.html

AND the BLOG was based on my Lecture Notes > Interior Components and Systems: Windows >>

http://www.gautamshah.in

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PERCEPTION of SPATIAL FIELDS -ILLUMINATION

 Post 643 –by Gautam Shah  (Lecture series: Space Perception’ -Article-1 of 15)

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The Illumination in a space is fairly consistent due the fairly steady source and predictability of the change. As one moves around a spatial field, things are perceived from different positions and in different contextual conditions. Other important factor that leads to changed perception is the increasing maturity of cognition. With the duration and proximity we learn lot more about the spatial field.

There are many ways the eyes move. “Our eyes converge as well as diverge” according to the intensity of light and size of the field to be scanned. The fovea region in the retina of the eyes helps in perception movement. In even seemingly non-moving eyes, small jiggling movements, called micro-saccades to occur. The broadest movements occur with gestural movement of eyes and heads and shifting during postures.

A spatial field has many depths.

Some fields, closer to the position of perception are illuminated with sources under our own control. Here the illumination conditions can be changed at will, or the position of perception shifted around. In both of these cases, the cause-effect has some certainty.

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Night time illumination -controlled phenomena > MaxPixel image (http://maxpixel.freegreatpicture.com/Bistro-Dining-Tables-Restaurant-Local-Inn-Table-261894)

Fields that are faraway from the position of perception are illuminated with sources under no-one’s control. Here the illumination conditions cannot be altered at will. Shifting the position of perception perhaps changes the contextual conditions, but the illumination component of the scene remains nearly static.

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Casa del Larario di Achille > Wikipedia image by Mentnafunangann

 ● In very vast natural scapes the contrasts (changes) due to illumination are not highly noticed except in variable cloud cover, or during sunlight refraction at morning-evening periods.A brilliant sunrise, sunset or cloud formation in illuminated distant sky, show very little effect on the perception foreground of landscape’.

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Pester Plateau Serbia > Wikipedia image by Zcvetkovic

● The effects of illumination are more pronounced and under control in restrictive space fields such as the built-forms, interior spaces and neighbourhood extents. Here the changes in contextual conditions accompany the changes in the foreground or components of the scene, so both seem controlled and restrained.

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Restrictive Space Fields > Pixabay Image > (https://pixabay.com/en/architecture-lines-and-curves-1839107/)

The ILLUMINANTS

A spatial field is illuminated by natural light as Direct sun light, Sky Component (SC), Reflected Component (RC) of natural light, artificial illumination, and in many urban areas from surroundings’ lights like a street and vehicles. In addition to these sources, we use fluorescence to aid perception.

Fluorescence and phosphorescence are form of luminescence, or the emission of light by a substance that has absorbed light or other electromagnetic radiation.

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Emulated illumination sources > Pexels image by Alexander Dummer (https://www.pexels.com/photo/photo-studio-with-white-wooden-framed-wall-mirror-134469/)

The illuminants’ contexts are: strength and direction of source, background and foreground brightness, reflectance from surroundings, colour of light, multiplicity of sources. Other conditions include variability of space, objects and presence of dynamic (moving-vibrating) elements.

Built Space forms are occupied by objects, people and environmental effects but these rarely occur distinctly alone, in any rational form or within a nominal framing reference. The illuminants complicate the scene even if these elements manifest in for a fraction of a moment or remain unvaried for a very long period.

Single source illuminants are very definitive but complications arise due to the reflectance from many surfaces, directions, strength (brightness) and colour. Such complications are compounded with increasing number of original illuminants. Single illuminant defines a space and its objects in familiar sense, but fail as soon as the position of perception changes. Single illuminant is an irritant if any part of space has flickering movement (eg. Fan, moving curtains). Single illuminants are ideal for ‘object modelling’ as the shapes emerge without any compromises.

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Monotone surface colour and texture allows certain ambiguities of perception (https://pixabay.com/en/concrete-spritual-architcture-1136218/)

Perception ambiguities and compromises occur when an object or a group of overlapping objects, are lit by nearly same tonal colour value as the background. Indistinct figure-ground contrast, dissolve the edges. We tend to relate larger elements as the ground, over which smaller entities exist.

The objects are seen composition of surfaces that reflect incident light. Besides the variations caused by the angular exposition of surfaces, the surface quality or textures are detected by naked eye (at 0.07 mm). Smaller scale variations affect the gloss of the surface and mirroring effect of the surface. Very large surfaces have possibly no edges or breaks, and so are perceived through local variations of illumination.

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Ambiguities of Perception due to illumination and form > (https://pixabay.com/en/tunnel-end-architecture-passage-2033982/)

SPATIAL FORM RECOGNITION

Spatial forms are recognized with illumination references such as the proportionate extent of foreground-background, framing, strength of silhouettes, partial occlusion of elements, shading with the differing contrast and direction of the shadows, and diffusion by way of reflection, and refractions.

Illuminated forms become difficult to recognize when an object curves around out of sight. Such occluding contours dissolve the edge of an object, and present poor silhouette formation. The absence of a well-defined contour renders the surface shapes (such as convex/concave) ambiguous.

The process of perception is a two-way affair. Position of a person and relative source of illumination are very important consideration for Space Planning. A person trying to project own-self must be aware of the perceiver’s distance, angles of connection, social dependency and postural condition. A strong back illumination, makes it difficult to perceive a chair-person’s features and gestures.

Position of a person relative to the source of illumination also holds true in conference rooms, executive cabins, reception areas, lecture rooms, press conference rooms, etc. Natural or artificial illumination -as singular source and that too from the backside must be avoided, and if inevitable, reinforce it with lighting from other directions. One of the simplest ways is to envision how the situation manifests from every single position.

The daytime happenings, change considerably at supper time, as the ‘backbite window’ illumination is replaced with artificial lighting. Nominally the situation should stand corrected (if not reversed), but attitudes formed during daytime persist at other times. Shops in business districts are low illuminated because the staff is occupying the space for longer time and so is accustomed to low level (or even to save power), but customer entering from bright outside finds the darkness discouraging.

Side illumination eliminates many of the anomalies of perception and recognition but not all. To create good diffusion, the source for side illumination needs some depth from the occupying position. In small rooms this is rather difficult and requires careful design.

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Sound and Light shows use bottom up light for scene building, making them scary and giving unreal feel > Gwalior Fort India, > Wikipedia image by Ashish Thapar

We are more used to illumination from top. But very strong such sources create under the chin shadows. This can be corrected by illumination from other directions, or from floor and table top reflections. Light colour floors and table tops, needs to be excluded from TV camera shooting angles. This is done by positioning the participants on a raised platform, and cameras at a slightly lower level then the table tops.

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This is Article-1 (of 15) in Lecture series: ‘Space Perception’

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OBJECTS in SPATIAL FIELDS -Issues for Design -14

Post 642 –by Gautam Shah

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A spatial field is a definable extent of reality, occupied by: Physical elements such as objects, humans and other beings, Non physical things like environmental effects, air, illumination, etc. and Ephemeral presences like relationships, geometries, remembrances.

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Milan Cathedral Roof > Wikipedia image by Jakub Halun

 The SPATIAL FIELD

The spatial field consists of:

1 changing environmental conditions;

2 elements that are distanced from other elements, and so have potent relationships;

3 elements that are adjacent and so allow comparisons of scale or contrast, and have implicit connections;

4  elements that are partly concealed by other elements covering up the cuts, corners, edges and such other definitive elements, and have characteristic scale and distance;

5 elements obscuring the presence of other elements.

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A Tree obscuring the important junction detail > Pixabay Image by WikiImages Deutsch

ELEMENTS of SPATIAL FIELD

Spatial field and Environment are perceptible totality. A spatial field is perceived as a static event but the changing environment make it a dynamic happening.Changes are necessary in the spatial fields for us to see anything at all”. Other dynamics include, eye and body movements, changes in surroundings, movement of the objects, and shifting position of the perceiver.

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Spatial field and the Environment Holes in the roof > Flickr image by Hans Splinter

The elements in spatial fields have surfaces with colour and texture. The surfaces also have geometric configurations like convex, concave single or double curvatures. The surfaces have edges at the ends and intermediate breaks. The surfaces, present themselves with inclinations towards or away, in vertical, horizontal and other directions from the perceiver.

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Multiplicity of forms and Complexity > Roofs MaxPixel image (http://maxpixel.freegreatpicture.com/House-Roofs-Roofs-Architecture-Roofing-Red-Tile-565362

The elements in spatial fields have forms. The forms are composed of planes that are representations of solids, pretender fill-in-planes between wire networks, or apparent surfaces that are evident between points. These forms have two distinct qualities: have a gravity-based orientation or references, and are perceived in receding perspective. The second quality is highly dynamic, so offers a taste of reality.

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Forms in spatial field > The Willow Tearooms Glasgow designed by Charles Rennie Mackintosh > Wikipedia image by Dave souza

The forms can be of lines, such as in wire-frames, within which the surfaces are presumed to dwell, but without the nominative texture or colour. In such hollowed forms, the shadows of the frames complicate the perception of the holistic form.

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Roof frame for the Royal Albert Hall > Wikipedia image by KlickingKarl

The forms in spatial fields are compositions of regular or familiar surfaces, so even a partial reveal can disclose the entireness. Where the forms are of continuously and irregularly varying surfaces, then unless entire form is perceptible or from many directions, its totality cannot be known.

The forms in spatial fields often have orientation of sub-segments that depicts a direction or movement. When such directions are congruent, the form gains a momentum. Similar ‘things’ appear to be grouped together. Alternatively we connect several incoherent elements into a form with dominant theme  of the scene.

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Building a narrative from Elements > Pixabay image by WikiImages Deutsch

Scene building or Spatial narratives commence from parts. One takes in few particular sets, rather than searching for the wholeness. The scene or the narratives get built when cognized sets and our past experiences come together. “We do not just see, but look”. In a spatial field scene building occurs by moving along a predefined path, by shifting the elements and by delaying, hastening or filtering the environmental effects. Designers build scenes or spatial narratives by framing the vista with opportunistic framing, occluding certain sections and by modifying the foreground-background contrasts.

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Modelling the elements in a spatial field > Corridor > Pexels image

Modelling the Elements in spatial field, is posing of objects and people including own self, to make them noticeable. The process first requires the realization and than corrective measures. For realization one needs to perceive the element from multiple cues, which may be similar to many others, close to each other, interconnected, and part of a complex pattern. The corrective measures include perceptual aggregation of a visual scene. Here the edges, if, are breached, need virtual bridges, to form a larger extent and a perceptible whole.

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Securing a coherent pattern from multiple elements > Many stories on stairs > L’Arche de la Defense Paris > Flickr Image by Pierre Metivier

Structuring a pattern from multiplicity of elements is a process carried out in many different environmental conditions, referencing cues and positions of perception. Regions of space are natural zones, and elements occurring in them seem related. Such regions of space have similar environmental exposure, form, extent, or belong to the same perspective. Patterns replicate a form in many scaled versions, similarity of placement, orientation and contextual relevance.

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Cyclist in foreground against a simpler background forming a silhouette > Flickr Image by Pierre Metivier 

Silhouettes in a spatial field are the edges or boundaries of forms. Edges distinctly delineate or separate the foreground (from background). Extreme silhouettes emerge when the foreground (the form) is extensive and without any details, and the background is vibrant. The vibrant background helps in bridging the breaks that may exist in the form. Distinguishing the foreground from the background is a task difficult for scenes that fall in visual (cone) of perception. Nominally we perceive dark colour to be a deeper element and the lighter colour to be a nearer one, but with silhouette formation a reversal is forced, creating a myth. Silhouettes in nature (sun-set or sun-rise) are short lasting, so elements with back-lit fields are perceived to be transient.

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Background-Foreground with equal value > Horses in Parc du Chateau de Versailles > Flickr Image by Pierre Metivier

Familiarity in Spatial field is unexplainable connection. Things that are in a foreground are proximate, and so have the first claim of familiarity. The relevance of purpose offers next level of familiarity. But when other elements in the scene compete in terms of size, orientation or distancing, a dilemma occurs.

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Recognition due to the elemental familiarity > Petra Jordan > Flickr Image by Pierre Metivier

Stratification of view in a spatial field occurs at many different scales. Stratification is horizontal sectioning and vertical segmentation, and both aided by situation and architectural elements. A person at the interior edge can view the exterior with movement of head and eyes, but from a depth visual limitation is imposed. Similarly skylights allow unchanging sky view whereas a very tall sill level cuts-off the view of the ground.

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This is the 14 th article of 20 topics series on ISSUES for DESIGN

 

Links to Blogs on ISSUES of DESIGN

 

Post 641 –by Gautam Shah

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These are 13 articles (already published) in a proposed series of 20 articles.

 

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1 BODY POSTURES – Issues for Design -1
https://interiordesignassist.wordpress.com/2016/04/30/body-postures-issues-for-design/

2 INTERVENTIVE SPACES  – Issues for Design -2
https://interiordesignassist.wordpress.com/2016/05/13/interventive-spaces-issues-for-design-2/

3 PERCEPTION through SCALES and CONVERSIONS -Issues for Design -3
https://interiordesignassist.wordpress.com/2016/05/17/perception-through-scales-and-conversions-issues-for-design-3/

4 SPACE PERCEPTION – Issues for Design -4
https://interiordesignassist.wordpress.com/2016/05/24/space-perception-issues-for-design-4/

5 MOVEMENT and BALANCE – Issues for Design -5
https://interiordesignassist.wordpress.com/2016/06/06/movement-and-balance-issues-for-design-5/

6 NON VISUAL LANGUAGE -Issues for Design -6
https://interiordesignassist.wordpress.com/2016/06/10/non-visual-language-issues-for-design-6/

7 DESIGNERS and QUALITY -Issues for Design -7
https://interiordesignassist.wordpress.com/2016/06/20/designers-and-quality-issues-for-design-7/

8 ANTILIGATURE -Issues for Design -8
https://interiordesignassist.wordpress.com/2016/06/28/anti-ligature-issues-for-design-8/

9 SCALING the SPACES -Issues for Design-9
https://interiordesignassist.wordpress.com/2016/07/22/scaling-the-spaces-issues-for-design-9/

10 REAL and VIRTUAL -Issues for design-10
https://interiordesignassist.wordpress.com/2016/08/18/real-and-virtual-issues-for-design-10/

11 METAPHOR Issues for Design -11
https://interiordesignassist.wordpress.com/2016/09/12/metaphor-issues-for-design-11/

12 CONTEXT -Issues for Design -12
https://interiordesignassist.wordpress.com/2016/11/08/context-issues-for-design-12/

13 SOLIDS and VOIDS -issues of Design -13
https://interiordesignassist.wordpress.com/2017/02/04/solids-and-voids-issues-for-design-13/

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