Talk Given at the Annual Convention of the National Association of Students of Architecture

I gave a talk and conducted a workshop at Footprints, the annual convention of the National Association of Students of Architecture (NASA), held at the Gateway College of Architecture & Design from January 25th to 28th.

Here is a slide show and transcript of my talk –

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Alternative Computation

Today I’m going to talk about the use of computation in architecture. A lot has been said about computation and its role in architecture since the early 1980s. Today, virtually any architectural practice uses computers in some form or the other. But it is not just architecture. Today, virtually any profession uses a computer in some form or the other.

So what is it that computation offers?

I am sure that all of you have wished that there was an “UNDO” command that you could use when you have made a mistake while building a model for your design studio. But of course, there is no “UNDO” command outside the computer. Have you ever wondered why?

In order to understand why this is so, I am going to have to briefly switch from architecture to thermodynamics. I am sure that all of you are familiar with the Second Law of Thermodynamics from your physics class in school. One version of this law states that “The disorder in a closed system will always increase.”

What this means is that you are not going to see spilt milk spontaneously gather back into a glass. You cannot “UNDO” the spilling of milk. And some people argue that the Second Law is what defines the direction in which time flows.

But how is it that a computer allows us to “UNDO” things? How is a plant able to grow with soil, water and sunlight? How does a machine make something as complex as a computer in the first place? These are all examples of more order being made from less order.

Well, there is a very convenient loophole to the Second Law. If you add energy to a system then you can increase order. The addition of energy from outside means that the system is no longer closed, but then no system is ever completely closed anyway.

The addition of energy therefore frees us from the second law. Plugging a Xerox machine into a socket allows it to make copies. Light falling on a leaf enables a plant to grow through photosynthesis and ultimately reproduce. Powering up a computer lets it “UNDO.”

So the way a system uses energy determines its relationship to disorder. On this basis, one can think of four different “Realms” or “Paradigms” – the mineral realm, where disorder always increases; the biological realm where order is propagated; the mechanical realm where disorder is controlled and order is created; and the digital realm where there is no disorder.

So what does the digital realm, with no disorder, offer the architecture?

It offers a clean slate as the starting screen of any CAD software will show you. It offers a void with no disorder where you are free to design without any encumbrances. You are free to do what you want.

While a blank sheet of paper is a two dimensional “void,” the computer offers a three dimensional blank slate. In addition to this, the computer offers the ability to process large amounts of information quickly.

If we think of “complexity” as the amount of information required to describe an object or phenomenon, then we can say that the information processing power of a computer allows architects to deal with complexity.

A project done by the studio that made use of what the digital realm offers is the Gateway to the JSPL power plant in Chhattisgarh, built in 2006. The form of this gateway creates a dialogue between local tribal geometries and industrial technology. The design development was undertaken through physical and 3D digital modelling with the geometric information of the digital model being used to create CNC pre-fabricated components that were assembled on site.

There was therefore a seamless flow of information from the digital model to the fabrication of the components by computer controlled machines which used data directly from the model. This allowed for very high precision and the coming together of the pre-fabricated parts smoothly on site in spite of the complexity of the form.

But if we re-visit the construction process of the gateway, we see that the digital realm, from which the design and the computer controlled fabrication comes, must eventually interact with the mineral, biological and mechanical realms. You see this in the critical step of fixing the structure to the footing in the ground. Had there been any mistake in the foundations, and had it not matched the digitally fabricated structure, there would have been no “UNDO.”

Another factor not immediately apparent is the amount of energy needed to manufacture the steel needed for the digital fabrication process. This energy is needed to create a material which is completely homogenous and uniform. The energy is needed to fuel machines which remove the disorder present in the mineral realm.

The removal of disorder from materials is needed when designing in the digital realm because design in the digital realm always begins with a perfectly ordered blank slate. And as long as one stays in the digital realm, there is no way of interacting with the disorder of other realms. While the digital design process can generate complexity, it cannot deal with disorder.

This is not a new thing in architecture. Historically, what has differentiated the architect from the master builder has been that the architect works on paper, in a space free of disorder. But the power of digital technologies available to architects today highlights the issue like never before.

The most obvious way to overcome this is to NOT start the design process in the digital realm – which is what I did in this small experiment with bamboo. Instead of starting with a blank slate, I started by scanning a piece of bamboo on a simple flatbed scanner, thereby digitizing disorder.

I used the scans of two pieces of bamboo to create digital models of them. Because I did not start with a blank slate but instead started by digitizing the disorder of the irregularly shaped bamboo, the computer had no problem in dealing with the complexity of its shape.

I then designed a joint between the two pieces where the angle is exactly 60 degrees. This joint was cut in the bamboo using a computer controlled router and the two pieces of bamboo were then tied with rope by hand. The computer was therefore able to negotiate the complexity of disorder and impose the order of a 60 degree joint on the bamboo.

But humans are much better at dealing with disorder. So can computers and humans collaborate with each other to build complex designs while negotiating disorder?

The first attempt at answering this question was the Parametric Pavilion project. For this project a parametric model was made to create a family of bamboo pavilions that can be built cheaply and quickly for a variety of functions. The parametric model can be manipulated to generate new forms based on programmatic requirements and site conditions. The parametric model outputs dimensioned drawings for construction on site where craftsmen negotiate the disorder inherent in bamboo with the computer generated dimensions.

The hyperbolic paraboloid shape of the pavilion as well as the gateway is part of a larger group of shapes known as ruled surfaces – surfaces that can be made from straight lines.

This geometry is such that the structure can be built using only length dimensions and there is no need to measure angles, curvatures, areas, etc. Linear measurements are the easiest to measure, requiring only a measuring tape to be placed against a piece of bamboo and lengths marked. The use of linear measurements minimizes the chances of errors and also makes the work of the craftsmen on site easier.

But can this technique of linear measurements be extended to more complex geometry?

If you take a flexible member and reduce the distance between its end points then it will curve. If you have a network of such members intersecting each other, then you can obtain virtually any surface you like. And this is nothing but weaving.

The Nest Roof is an on-going project where we are using weaving to construct a complex computer generated surface from bamboo through linear measurements alone.

The shape of the roof was the result of an algorithmic form-finding process resulting in a funicular shell structure. The shape of this shell was dictated by the plan form of the building.

It was decided to weave this shape out of bamboo as a reticulated shell structure. A reticulated shell is a doubly curved structure made from intersecting members of a flexible material. The flexibility of bamboo increases as it becomes thinner, but as it becomes thinner it also becomes weaker. The less a bamboo member has to curve, the thicker and stronger it can be. So an algorithm was created to find paths of minimal curvature along the shell surface along which to weave the bamboo.

The use of this algorithm allowed us to have 4” dia half-round bamboo members arranged in 6 layers to achieve a beam-depth of 2’.

In order to construct this, drawings were made where the lengths of bamboo between each intersection were given for each step of the weaving sequence. Since these lengths were more than the linear distance between the end points of each member, the desired curvature was achieved.

The craftsmen of site could therefore build this structurally optimized reticulated shell structure using only linear measurements. The craftsmen themselves could then focus on negotiating the disorder inherent in the bamboo such as joining two pieces of bamboo to create a continuous structural member, and place spacers of different sizes to absorb variations in the size of bamboo.

So, in this project the computer deals with the ordered aspect of design while human craftsmen deal with disorder, and, as architects we found an efficient way to transfer information from the computer to the craftsmen through linear measurements and weaving.

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