JOURNAL
ARCHITECTURE DESIGN STUDIO: AIR SARAH SKEELS - 392 089
1.1
CASE FOR INNOVATION About the Author Digital Design Architecture as a Discourse Computing in Architecture Parametric Modelling
1.2
RESEARCH AND EXPLORATION Wyndham City Gate Project Parametric Case Study The Bird’s Nest Exploration Matrix
1.3
MODEL MAKING Creating the Prototype
1.1 Case for Innovation
The Solomon R. Guggenheim Foundation, Bilbao (New York, 201 <http://www.guggenheim.org/bilbao>
12)
About the Author and Digital Design My name is Sarah Skeels and I am studying a Bachelor of Environments, majoring in Architecture. I originally started off as an Arts student at The University of Melbourne, but after a year of study, decided to transfer out of the degree. Previous to that, I was a student at Camberwell Girls Grammar School, where I was able to go on exchange to Germany during the summer of 07/08. On that, as well as on subsequent trips to Europe, I fell in love with buildings, their facades and how they manipulated space within both the interior and exterior of the structure, and how this changed for architecture between countries and within regions of countries. After graduating next year, I hope to take some time off to return to Europe to immerse myself in the rich culture and beautiful city streets of one of my favourite cities, Paris. My past experience with digital design is extremely limited. In semester 2, 2011 I completed the subject Virtual
Environments, where I used Rhino to create a design of a process found in nature that takes place over time. I found this to be an extremely frustrating experience, as my knowledge and ability on computers, let alone complicated programs such as Rhino, is not very good. However, as much as my ability was somewhat of an inhibitor to my designing, I found that using digital modeling to be extremely useful in many respects. What I found most advantageous was being able to see the model in 3D, and at numerous angles in the most up-todate version of the design, something that I find my paper sketches could not do. And although I canâ&#x20AC;&#x2122;t say from experience, because for me changing my design in even the slightest way took hours of laboriously pouring over online tutorials to figure out which button or command I should use, I could see from my tutorâ&#x20AC;&#x2122;s proficient use of the program, that such things could be done almost effortlessly, swiftly and without the need for remaking models or redrawing sketches - saving both time and paper!
Zaha Hadid Architects, Vitra Fire Station (London, 2012) <http://www.zaha-hadid.com/architecture/vitra-fire-station-2/#>
Virtual Environments was the first (and only) insight I have been given into digital design but from it, I have been exposed to some incredible designs and buildings. The works by both Zaha Hadid and Frank Gehry are considered to be revolutionary in terms of architecture, for pushing the boundaries of what can be designed and built, with the aid of digital design techniques. I love the building Vitra Fire Station in Weil am Rhein in Germany by Zaha Hadid, with its use of linear lines, joining at irregular angles and this sense of movement captured within the building. It reminds me of an insect wanting to take off and fly away! So too does the Guggenheim Museum in Bilbao by Frank Gehry capture my attention but for different reasons. It is so curvaceous and unified; despite having numerous elements extruding from one another and for me also captures the notion of movement, looking like a boat resting on the water. It is buildings such as these that inspire and create discourse about digital architecture, its place in current society driven by seemingly the never ceasing developments made in technology at unprecedented rates, and the place digital technology holds in our future. Will architecture continue to develop as fast as the technology that can now make it, or will people revolt against living in this space age where nothing looks and acts like traditional notions of architecture?
Clockwise from top right: Yan, Brandon. Masters Planning: Bludgeoned into Modernity: Paris, Haussmann and the Opera (Vancouver, 2011) <http://mastersplanning.blogspot.com.au/2011/01/bludheoned-into-modernity-paris.html>
Hart-Davis, Damon, Earth Views: France-Paris-south-east-ornate-ironwork-stone-builiding-and-street-sign (Paris 2012) <http://gallery.hd.org/_c/places-and-sights/France-Paris-south-east-ornate-ironwork-stone-builiding-and-street-sign-1-CS.jpg.ht Paris Perfect, Paris Perfect (Paris 2012) <http://www.parisperfect.com/apartments-for-rent-in-paris/pastis.php> Paris Haussmann Centre, Paris Maps (2011) <http://mapsof.net/map/paris-haussmann-centre> Blanchard, Antoine, Le Boulevard, Paris (New York, 1999) <http://www.antoineblanchard.org/view_image.html?image_no=188>
tml>
Architecture as a Discourse The Parisian buildings that line the major boulevards of Paris with Mansard roofs, while not a specific building but rather a neo-classical style of building are to me one of the most attractive facades to a building. They overpower me with a sense of grandness, elegance and romanticism and I feel drawn in and captivated by the uniqueness of style, one that is very French and very Parisian. One of the things I love about these buildings is the atmosphere these grand, elegant facades create on street level and how these buildings lend themselves to city life. With cafes and boutiques all along the street front, one is drawn to these social boulevards, captivated and enticed to stay, swept up in the French city centre. It is interesting to note that while this project is nearly 200 years old, the notion of urban planning, developed heavily in the 20th century, particularly in the new and booming auto-cities of The United States of America, looked to these ideas of street width, the movement of cars through the city, places of green space for patrons of the city to enjoy and what was the optimal way to incorporate these and arrange them within a city landscape. This became a worldwide debate that continues to this day, with variations to theories made depending on the social issues of the time. Nowadays this tends to be driven by a desire to be environmentally friendly, public transport effective and produce as little pollution as possible.
Clockwise from left: A. & U. Kohler, Westminster Abbey, (UNESCO World Heritage in Westminster, 2010) <http://www.sights-and-culture.com/London/Westminster-Abbey.html> London English Language School, Westminster Abbey (London, 2011) <http://www.ecenglish.com/blogs/London?2011/02/16/ec-trip-to-westminster-abbey/> Westminster Abbey (London, 2010) <http://www.luckylittletravelers.com/kidtravelweb-london-westminster.html>
The Westminster Abbey in London is to me one of the classic examples of Gothic architecture - and does everything that is associated with that movement - strike fear, awe and amazement in me. While quite an elegant and graceful building, with the great presence of symmetry seen in its facades and decorations, I am swept up in the history exuding from the building. I can imagine the stone masons, who worked tirelessly carving and building the structure, the congregation pouring in to admire its splendor, decoration and detail once it was completed, the nobles who have passed through its doors, walked down the aisle, or sat in the pews watching. I can imagine the fear of little children running past on a cold, rainy night to see the dark blurry shapes of gargoyles and the points of arches looming over them and the majesty of the building the next morning, once the rain has cleared and the sun is shining down. I am in love with the images and imaginings with which this building conjures up. While not a ‘current’ or ‘pertinent’ style of today’s discourse, the Gothic Abbeys and Cathedrals in England, France and across Western Europe were once at the forefront of technology, much the same way digital design is currently. Both styles have almost polarized people, with those who were embracing the change, the technology and the newfound boundaries that had been crossed, while there were those who found the Gothic or find digital design too eccentric and over the top.
“What, then, is the use of computers for the process of design, which requires both rational and creative abilities, if they lack one of the two key ingredients needed to solve design problems?”
Computers in the Architectural Design Process The use of computers in the architectural design is ever increasing. But in an ‘Age of Technology,’ where everything can be seen, read or heard digitally, through increasingly portable and ‘smart’ phones, cameras, and laptops, is it hardly surprising that design should go digital too? While Architecture may be following the social trends of the time, is it actually beneficial to the design process to do so? The short answer is yes. Architecture is intrinsically social. It is used to not only represent the Zeitgeist or the spirit, culture and society of the time in which it is designed, but also interacts socially with the people of the present and future time. This means that for modern day projects, to show the ‘spirit of the time,’ a design must interact with people on a technological level. This may be through creating amazing, mathematical creations inconceivable without the assistance of computers who “never make silly arithmetical mistakes”11 such as Frank Gehry’s Guggenheim Museum in Bilbao, or it may be in the often-unseen design and building process. It is in this latter designing and building process where digital architecture has marked a dramatic step forward from being merely a neat, precise and papersaving way of drawing plans, sections and elevations. With the creation of NURB modeling software, digital design has progressed from a representational tool to a designing tool where an architect can move from limiting design possibilities down through the implementation of site, brief or monetary restrictions, to imposing those restrictions through software programming and allowing the computer to generate seemingly endless possibilities with the manipulation of one or two factors. The architect has moved from the making of form to the finding of form. These computer-generated designs come uninhibited and unrestricted by the architect’s ideas, social or cultural beliefs or attitudes and can even defy the laws of physics! 1 Kalay, Yehuda E. (2004). Architecture’s New Media: Principles, Theories, and Methods of Computer-Aided Design (Cambridge, MA: MIT Press), pp 2.
Gehry Tower - Hannover (Yahoo, 2012) <http://www.flickr.com/photos/piotrkrajewski/5712054325/> Kolarevic, Branko, Architecture in the Digital Age: Design and Manufacturing (New York; London: Spon Press, 2003), pp 21-22.
The role of Metamorphosis in digital architecture has allowed Architects to further alter and transform geometric shapes to create new, interesting and boundary pushing designs. The simple acts of twisting and bending can lead to “unknown and impossible to preconceive or predict” outcomes.2 1A simple twisting of a prism like in Gehry’s Ustra Office Building can create an elegant, unexpected form in the built landscape. So too can deformations such as in Eisenman’s Bibliotheque de L’Ihuei design process produce shapes and forms that may not readily come to an architect’s imagination. Sometimes however, the metamorphosis of buildings and objects can lead the general public confused and overwhelmed, unable to interpret and use the resulting product. 1 Kolarevic, Branko, Architecture in the Digital Age: Design and Manufacturing (New York; London: Spon Press, 2003), pp 22.
Wolf D. Prix & Partners, Coop Himmelb(l)au (2012) <http://www.coop-himmelblau.at/>
Parametric Modelling Parametric Modelling is a very recent addition to the design process of architects. As such, there is still a lot of disagreement as to the advantages or disadvantages of such technology and its use. Some of the advantages of parametric modelling include: - Public awe at the unconventional, spectacular and flamboyant buildings that can be created. - Architects are able to create and design buildings faster then ever before. - Designs are no longer confined to follow conventional shapes like squares, spheres or triangles, the use of NURBs allows for free lines, with shapes defined by the architect, not geometry.
Some of the disadvantages include: - Exponential costs involved in constructing such unconventional forms, which are rarely able to have elements mass-produced. - Due to these rising costs, and the Global Financial Crisis that we currently find ourselves within, the majority of these parametric designs are confined to the realm of paper architecture and are therefore rarely able to be observed or understood by the general public, whose main connection with architecture is not through academic discourse but the ability to see â&#x20AC;&#x153;styleâ&#x20AC;? or aesthetics. - It is argued by many, both within and from those outside of the architecture profession that this new parametric and digital architecture denigrated style as buildings have transformed from an expression of order and cohesiveness to blob-like forms that either transcend or ignore the rules of style, depending on oneâ&#x20AC;&#x2122;s perspective.
Zaha Hadid Archiects, Heydar Aliyev Centre - Architecture, (London, 2012) <http://www.zaha-hadid.com/architecture/heydar-aliyev-cultural-centre/>
Two designs that celebrate the use of NURBs and free flowing lines and shapes are Coop Himmelb(l)au’s BMW Welt and Zaha Hadid’s Heydar Akiyev Centre. They capture the awe of the public and architects alike, but also portray one of the main problems that prohibit parametric modelling from becoming the new style, as argued by Schumacher. These new and flamboyant designs are restricted to those commissioners who are extremely wealthy, and are consequently restricted to the public sphere – these parametric designs do not cater for domestic dwellings, but instead consist of pavilions, art galleries, concert halls and museums.1 If parametric modelling is able to enter the domestic life, it will not be the fad that Mayer believes it will be, it will perhaps instead become a new movement, set to transform the 21st Century. 1 Schumacher, Patrik, “Let the style wars begin,” (London: EMAP LTD. 2010) <http://www.architectsjournal.co.uk/thecritics/patrik-schumacher-on-parametricism-let-the-stylewars-begin/5217211.article>
1.2 Research and Exploration
Wolf D. Prix & Partners, Coop Himmelb(l)au (2012) <http://www.coop-himmelblau.at/>
The Wyndham City Gate Project The Discourse surrounding Parametric Modeling is both very interesting and somewhat confusing. Even while the very legitimacy of Parametric Design as a design tool and indeed as the design tool for the future of architecture are still very much in flux, it is still very seductive looking at the unique forms and shapes it can create. It is precisely this feature of interest, intrigue and uniqueness that make Parametric Modeling the perfect device for the Wyndham City Gate Project. The images on the left of some of the work by Coop Himmelb(l)au, both built and unbuilt provide an insight into the creative forms, with soft curves projected at gravity-defying angles and plans that Parametric Modelling is able to create, It is this structural form that both Antonia and I wish to focus on while creating our own parametric design for the Wyndham City Gate Project. We believe that the crafting and shaping of the structural curves, twists and angled projections will provide both a unique and interesting experience when entering the City of Wyndham.
24d Studio, Crater Lake (New York, 2012) <http://www.24d-studio.com/crater-lake.html> Lowenstein, Oliver, The Savill Gardens Gridshell, Glen Howells Architects (2012) <http://www.fourthdoor.org/annular/?page_id=453>
Antonia and I also took inspiration from “The Crater Lake” by 24 Studio and “Mannheim” by Frei Otto. The combinations of self-supporting structure, aesthetics through various paneling and the structure creating the floor, walls and ceiling were all aspects that we wanted to capture within our own design.
Wolf D. Prix & Partners, Coop Himmelb(l)au (2012) <http://www.coop-himmelblau.at/>
Parametric Case Study Museum of Contempory Art and Planning Exhibition Coop Himmelb(l)auâ&#x20AC;&#x2122;s Museum of Contemporary Art and Planning Exhibition (MOCAPE) in Shenzhen, China, is a beautiful example of structure, celebrated through the interior of the building with the frame very aparent and merely coated in glass. On the exterior too, the softness of the curve growing to become the roof over the entrance broken only by the sheets of mrtal that encase the frame. It is in curves such as this that the use of parametric design techniques is obviuos, Without it, the ability to draw, calculate the angles of each single element within the curve and then build it would be almost impossible or at least extrodinarily time consuming as the curve is bending in more then one plane. Unfortunately there are not images showing the exact design process that Coop Himmelb(l)au have taken in constructing each layer, each curve and manipulating it all together, howver Antonia has found some parametric definitions that give us an insight into how one might go about designing such curves for a functional building.
Amazing Olympic Architecture in Beijing, China, (2008) <http://www.readthesmiths.com/articles/travel/Amazing_Olympic_Architecture_in_Beijing_China>
The Bird’s Nest “Our most important principle throughout has been to develop an architecture that will continue to be functional following the Games in 2008, in other words, to create a new kind of urban site that will attract and generate public life in this part of Beijing.” Herzong & De Meuron 2007
The Bird’s Nest, or The National Stadium in Beijing was not built purely for use as a sports stadium during the 2008 Olympics but was designed instead to become a new part of the city’s social interaction. Two of the design requirements put forward by the selection panel were that of a retractable roof and low maintenance costs. It is interesting how these requirement influenced the design of the stadium, resulting in this steel encased nest facade. It was precisely this structural facade that the group wished to focus on. While it is successful in providing large amounts of natural ventilation to the building, aiding in maintaining low running costs, it is interesting at how this somewhat random looking pipe work provides the important structural support of the stadium, while also creating a very iconic appearance. As a group, we wished to investigate this further. We wanted to look at how honest in its expression the steel structure was, how the structure forms the shape and form of the stadium and how this single element creates the internal and external space, by being floor, wall and ceiling all at one time.
Recreating the Bird’s Nest in Grasshopper The process that the group used in recreating the Bird’s Nest in Grasshopper looking back was probably not the most direct and simple method to use. However, even though this process was somewhat convoluted, it will be broken down into the steps we took to achieve a successful outcome.
Step 1: Defining what we wanted to recreate. We wanted to reproduce the random pattern of the steel structure of the Bird’s Nest, and in order to do this, we needed random points, planes and curves.
Step 2: Understanding and defining what we had. We had found a Grasshopper definition on the Grasshopper website that recreated the randomness of the line work on the Bird’s Nest, however on a sphere instead of the actual Stadium shape. We also had the help of our tutor Paul, who helped us to put together a sort of action plan that we might be able to use in creating a surface, dividing the points, rotating their planes and creating the appearance of random curves through that.
Step 3: Identifying problems and attributes within the methods we had. One of the biggest problems we found with the Grasshopper definition we found online was that the definition was based around creating random looking curves through random points around the sphere and the centroid. When we tried to substitute the shape to a torus, these random curves became a very repetitive pattern. However this definition provided us with a good way of representing the curves through the pipe work. One of the biggest problems we faced with the method that Paul assisted us in creating was that we couldn’t create the amount of randomness within out points and curves that we wanted. When creating the planes, we found that we could only rotate these planes in 2 dimensions, however we wanted to rotate them in 3-D space. We discovered that instead of trying to rotate the planes in numerous ways, there were other, easier ways in which we could go about recreating the Bird’s Nest.
Step 4: What we did: Step 1: Finding existing Grasshopper definitions and trying to understand them so that we might manipulate them.
Step 2: Create a new surface to form the basis of the pipe work.
Step 3: Create sections between planes and surfaces to try and reproduce the randomness of the structure. Step 4: Create random points around the surface. Step 5: Create planes between the surface and the intersecting random points.
Step 6: Creating curves between the random points surrounding the surface and the random points intersecting with the surface. Step 7: Representing these curves in a fashion similar to that of the Birdâ&#x20AC;&#x2122;s Nest, with pipe work.
Similarities and Differences between the Bird’s Nest and our group’s Recreation. Similarities: - Appearance of random line work to create the facade - Similar in shape, with two slightly taller sides and two slightly shorter sides - 3-D elements to create the pipes of the facade
Differences: - There has been no structural consideration to the line work of our recreation, it is purely aesthetic. There is also no mathematical element behind our pipe work, unlike the actual Bird’s Nest - Our pipe work has very little depth into or extruding from the facade. It is very flat whereas the Bird’s Nest’s facade is 12m in depth - Our recreation has no sense of symmetry to it, whereas the Bird’s Nest is symmetrical in at least one axis
Our Outcome and Future Possibilities. Compared to the original definition we had found online, as well as others that were also being published in the same domain, I believe that our group’s effort is really good. We have managed to quite successfully recreate the shape of the stadium, and the seeming randomness of the line work around the facade. I believe that the only area in which our representation falls down is in the fact that the facade has no depth to it, and the random lines do not identically follow the random lines of the actual Stadium. Personally, if we were to further develop this style of random pipes creating both the facade and structure of the building, I would like to develop an althernate shape to the stadium, but still maintaining the softness of the curves between the wall and roof segments of the building, and the harmony between these soft curve of the facade and the softness of the line work making up the facade. Instead of creating a 3-D space, I think it would be interesting to have this sort of structure without an interior, and more 2-D.
Exploration Matrix Manipulating the density of points from which the curves are made In developing the Grasshopper Definition of the Birdâ&#x20AC;&#x2122;s Nest, as a group we looked at manipulating the associations and outputs of the definition. Initially, the definition set random curves, displayed as pipes, between a random set of points within a boundary box around the lofted surface, and a set of points on the lofted surface. We played around with increasing the density of both these two sets of points individually, then at the same time to see what sorts of lines might be created. We found that when one or two of the manipulatable aspects were set to low numbers, the outputs looked a lot more visually appealing. When the numbers used were quite high, the nest started to look really dense and uninteresting and was not something we found visually appealing. In these scenarios, there was less of an attraction to how the structure is making the shape as apposed to it being almost its own separate facade. With the earlier attempts, it is very clear how the facade and structure are the same and how each curve grows and weaves its way around the lofted shape. It was this aspect that we were interested in achieving. We further continued to modify our original definition by changing the output of the curves created by the random points. We chose to represent these as circles. We then went on to alter the size of the radius, the density of the circles then to change the density and size of the circles as they approached an attractor point around the shape. Moving this attractor point also created some interesting results. We then chose some of the manipulated aspects of our definition that we liked the best and tried to combine these together further. We were really focused on a way to synthesis the facade and structure into one, while maintaining a sense of randomness to see how this affected and created negative space both within the structure itself and the space around it.
AN D
AN D
P O I N T S
A XI S
PO I N T
AN D
GR I D
AT TR AC TOR
SU R FACE
AT TR AC TOR
N OR M AL
SA M PLE R
CI RCLE ,
I M AGE
ATT. PT. TO PIPE´S RADIUS
CI RCLE
CI RCLE
S E T
C E N T R O I D
2
PO I NT
A. PATTERN
B. SHAPE
C. COMBINATION
II. Ideas - Geometry-structure, shelling I. Referents
- Frei Otto (Structured Shells)
- Continous surface,
- Eladio Dieste
continuity of the space and
II. Tools
- Solano Benitez
diferent uses
- Grass Hopper
- Bird´s Nest Stadium
- Negative spaces, created
-Rhino-Vault
- Crater Lake
by the bends and curves of
- Shigeru Ban
SHAPE = STRUCTURE
the surface/shell - Space conditionated by the structure and its pattern. - Permeability.
Our Design Process So Far - Bird´s Nest Stadium - Grass Hopper exploration
A. PATTERN Conditionates the space C. COMBINATION Decition: Wich option is the best for our project B. SHAPE As the same thing as the structure
- Shell Strucutres: Frei Otto - Compressed Structures: E.Dieste, S. Benitez - Rhino-Vault exploration
- Crater Lake, 24 Studio
D. CONSTRUCTION Solutions: materials, joints, etc.
- Shigeru Ban, Japan Pavillion
Creating our Final Combination
References: Kalay, Yehuda E. Architectureâ&#x20AC;&#x2122;s New Media: Principles, Theories, and Methods of Computer-Aided Design (Cambridge, MA: MIT Press, 2004), pp 5 - 25. Kolarevic, Branko, Architecture in the Digital Age: Design and Manufacturing (New York; London: Spon Press, 2003), pp 2 - 28. Schumacher, Patrik, Let the style wars begin, (London: EMAP LTD. 2010) <http://www.architectsjournal.co.uk/the-critics/patrik-schumacher-on-parametricism-let-the-style-wars-begin/5217211.article>
Images: A. & U. Kohler, Westminster Abbey, (UNESCO World Heritage in Westminster, 2010) <http://www.sights-and-culture.com/London/Westminster-Abbey.html> Amazing Olympic Architecture in Beijing, China, (2008) <http://www.readthesmiths.com/articles/travel/Amazing_Olympic_Architecture_in_Beijing_China> Blanchard, Antoine, Le Boulevard, Paris (New York, 1999) <http://www.antoineblanchard.org/view_image.html?image_no=188> Case for Innovation Cover Image: Gomes, Fernando. Gehryâ&#x20AC;&#x2122;s Sketch of the Guggenheim Bilbao, Spain, (UGO, 2001) <http://www.allmoviephoto.com/photo/2006_sketches_of_frank_gehry_014.html> Hart-Davis, Damon, Earth Views: France-Paris-south-east-ornate-ironwork-stone-builiding-and-street-sign (Paris 2012) <http://gallery.hd.org/_c/places-and-sights/France-Paris-south-east-ornate-ironwork-stone-builiding-and-streetsign-1-CS.jpg.html> Gehry Tower - Hannover (Yahoo, 2012) <http://www.flickr.com/photos/piotrkrajewski/5712054325/> London English Language School, Westminster Abbey (London, 2011) <http://www.ecenglish.com/blogs/London?2011/02/16/ec-trip-to-westminster-abbey/> Lowenstein, Oliver, The Savill Gardens Gridshell, Glen Howells Architects (2012) <http://www.fourthdoor.org/annular/?page_id=453> Paris Haussmann Centre, Paris Maps (2011) <http://mapsof.net/map/paris-haussmann-centre> Paris Perfect, Paris Perfect (Paris 2012) <http://www.parisperfect.com/apartments-for-rent-in-paris/pastis.php> The Solomon R. Guggenheim Foundation, Bilbao (New York, 2012) <http://www.guggenheim.org/bilbao> Westminster Abbey (London, 2010) <http://www.luckylittletravelers.com/kidtravelweb-london-westminster.html> Wolf D. Prix & Partners, Coop Himmelb(l)au (2012) <http://www.coop-himmelblau.at/> Yan, Brandon. Masters Planning: Bludgeoned into Modernity: Paris, Haussmann and the Opera (Vancouver, 2011) <http://mastersplanning.blogspot.com.au/2011/01/bludheoned-into-modernity-paris.html> Zaha Hadid Archiects, Heydar Aliyev Centre - Architecture, (London, 2012) <http://www.zaha-hadid.com/architecture/heydar-aliyev-cultural-centre/> Zaha Hadid Architects, Vitra Fire Station (London, 2012) <http://www.zaha-hadid.com/architecture/vitra-fire-station-2/#> 24d Studio, Crater Lake (New York, 2012) <http://www.24d-studio.com/crater-lake.html>