Architecture

From Top Down to Bottom Up

Generative design tools flip the script of architectural thinking

by Brett Duesing, Obleo Design Media

“Some might view computational design is just making some weird or crazy form,” says architectural designer Woo Jae Sung.  The 3D shapes may look arbitrary, but the method behind them is not.  “Contrary to the misconception, generative modeling is based on rationalism.  Our newly developed parametric tools were based on the needs of bottom-up design thinking.”

Designers have two different starting points when conceiving new structural forms, top-down and bottom-up.  Top-down is the classical, Cartesian-center technique of picking the overall shape first and then filling in the parts.  Bottom-up, as the name implies, is the opposite: it starts with geometric components as the initial building blocks.  Through repetition and variation according to logical rules, they grow to define larger systems.

Bottom-up conceptual approaches are found throughout other art disciplines, but it is still rare in architecture.  But Sung sees bottom-up as up and coming.  Sung recently taught a workshop at Cornell, where architectural students experiment with generating highly complex 3D forms by automatically repeating patterns of components.  The workshop uses the newly released application Grasshopper, a parametric plug-in for Rhinoceros’ 3D NURBS modeler.

“In my perspective, the generative design process is not a sub-discipline in architecture, but rather another paradigm,” says Sung.  “Traditional design tools prohibited us from thinking bottom-up, while parametric or generative tools are broadening our design perspective.”

Sung publishes his own Grasshopper Tutorial, a primer of getting started in the program, for Rhino users everywhere.  The tutorials are free on his blog, www.woojsung.com.  Sung says the tutorial content comes out of his own experiments in the software, where he tests his bottom-up theories and learns how to translate them into fully realized computer models.

“Before the advent of parametric and generative tools, doing bottom-up design was a time-consuming, painful, and rigorous process,” says Sung.   “Changes in parameters or relationships between objects meant that entire model should be done manually from the scratch.” He cites works by Eduardo Arroyo or Ciro Najle as examples of bottom-up processes without computer aid.

But with generative digital tools that can easily program geometric patterns, Sung and other a bottom-up artists now have a clearer opportunity to flip the script, so to speak, on the dominant paradigm of top-down thinking.

Housing Block ? Construction of Unite d’habitation in 1945. Le Corbusier’s housing layouts were heavily prescribed by a top?down Cartesian framework.

Housing Block: Construction of Unite d’habitation in 1945. Le Corbusier’s housing layouts were heavily prescribed by a top-down Cartesian framework.

Escaping from the grid

Tradition design tools, construction methods, and habit of mind have reinforced top-down thinking.  Look around at the environments where we live and work, and it is obvious that most of them began life as T-squared outlines on the drawing board.

Sung is starting to see generative output enter into real-world projects, although their application seems to be limited to textural additives, in the form of “crazy” contemporary ornamental patterns on wall panels of a building that was otherwise produced through top-down processes.

circles1

Ground rules– Woo Jae Sung’s bottom-up apartment alternative begins with a group of circles nest inside an acute angle. The circles can be rearranged within this boundary in different configurations. A wider angle grows the area of the circles.

Sung demonstrates that bottom-up design can go quite a bit deeper, to the point of defining the entire building form.  Recently, Sung explored the design of the Unite D’habitation, Marseille by Le Corbusier.  Considered iconic in modern architectural history, the 1945 housing block became a template of today’s urban living.

“My research revealed that unit types were not based on typology but heavily influenced by the rigid grid system,” says Sung, who re-organized the basic amenities of the complex by using bottom-up processes, which avoid the regimented repetition of the original Marseilles building while adding greater flexibility to the sizes and layouts of individual units.  “I wanted to propose an alternative way of making architecture based on the internal logic of the relationships, rather than the grid.”

The cylindrical re-conception allows for varied room configurations based on a set of basic geometric rules.  Like cross-sections of a tree, the roughly circular building floor plans resemble one another, but are also each unique.  As the floor layouts vary in form, the vertical supports of the cylinder gently curve back and forth, giving varied character to both the interior and the exterior.  Sung found the optimal solution for ten different floor plans in Grasshopper.

“I think this shows a different application of the parametric tool on architecture other than just wall patterns or mullions,” says Sung.  “Here the parametric tool is playing active role in generating form.

Various angle-circle configurations are assembled as a ring.  Since the <a href=

Natural Transformations

One of the appeals of a layered bottom-up process is that it is closer to that of natural organic growth, and so are the results.  Biological complexity is all bottom-up:  from molecules to cells, cells to tissues, and tissues to organisms.

Berkeley professor Christopher Alexander has literally filled volumes with good examples of form from nature and vernacular architecture, and bad examples from contemporary buildings in his book series, “The Nature of Order.”  He argues that top-down architecture, rooted as it is in abstract images and Cartesian grids, ends up lacking some hard-to-articulate quality.  “Soul” might be a way to put it.  In terms of experience, spaces created by top-down structures of mass-produced components can feel impersonal, cold, or “dead,” while buildings made through more organic generative methods seem to resonate as friendly, warm, and vitalizing.

These benefits may be subjective, but Sung’s attraction to the new design strategy originates more from the latitude it gives the designer when the grid no longer rules form.  “For me, bottom-up design process means control over power, flexibility over rigidity, and possibility over stability.”

Building Differently

A series of transformations within Grasshopper turns each angle into apartment units. A Voronoi algorithm turns the circles into room shapes; each ring design represents a unique high-rise floor plan.

 

Generative modeling tools like Grasshopper has opened the door to bottom-up design in architectural studios, but the remaining shift in perspective lies in construction site.  Concrete and steel – the cast-mold and frame-surface systems that now dominate construction – keep architects snapped into the grid.

“To build parametric-driven models, you need a mass-customization process, which requires construction paradigm change from cast-mold and frame-surface to sculpturing-modeling,” explains Sung.  “In the fields outside of architecture, we can see this happening.”

In making the quintessential top-down structure of Unite d’habitation, Le Corbusier drew inspiration for its structural system from ocean liners.  In what might be the future trend in 21st century architecture, bottom-up designers might look to the jet.  Aerospace parts exhibit strong, complex forms without the use of cast or frame systems.

“Considering that architecture has fallen behind other fields in adopting new ideas or methods,” says Sung, “sooner or later, the new paradigm will be more actively applied to architecture, and so will the application of generative modeling.”

Bottoms Up - The alternative housing complex model fleshed out in Rhinoceros after form-generation in Grasshopper. The slight variation in floor plans leads to organic curvatures to interior and exterior structural elements and a housing “block” where no two units are the same.

About Woo Jae Sung
Architect Woo Jae Sung is a graduate of Yonsei University, Seoul, Korea, and Cornell University’s School of Architecture in New York.  For more of Woo Jae Sung’s architectural examples and the latest edition of his Grasshopper tutorial, visit: www.woojsung.com.

About Grasshopper
For designers who are exploring new shapes using generative algorithms, Grasshopper™ is a graphical algorithm editor tightly integrated with Rhino’s 3-D modeling tools. Unlike RhinoScript, Grasshopper requires no knowledge of programming or scripting, but still allows designers to build form generators from the simple to the awe-inspiring.  For more information, please visit: www.grasshopper.rhino3D.com.


Stadium Elastique

Breathing Room: The gill-like openings of this stadium development model are adjustable within Grasshopper, as well as the slopes of its roofline and walls. Using parametric modeling <a href=

Studio Mode discovers working model flexibility in Grasshopper

by Brett Duesing, Obleo Design Media

Populous, a New York-based firm specializing in stadium design, recently entered its development phase on its winning concept for a soccer stadium in Monterrey, Mexico. Because of the continuous curves of the stadium, even minor adjustments in the form demanded a wholemonterrey02m1 series of changes throughout the model.  For example, a re-articulation of the exterior roof line might also affect the width of the gill-like openings on the sides.   With over a hundred slits, it’s a lot of tweaks.

“If they decided that the width of all the gill openings needed to be just slightly wider, they would have to spend four days revising the model,” explains Ronnie Parsons, principal at Brooklyn’s Studio Mode, a computational design firm that consulted with Populous on the project. “At this schematic stage they were experiencing a lot of design changes.  They wanted to be able review to refine the model, but not have the overhead of rebuilding the whole thing.”

With over a decade of combined experience in advanced scripting, Parsons and his partner, Gil Akos, have found their niche where digital design and programming intersect.Many of their clients are other architects who need to automate some of their processes to allow for more time to design. Their solution for the Monterrey stadium was to build parametric features into a NURBS model.In Mode’s parametric concept model, the user can make one modeling action and create global changes throughout the design.Raise the stadium dome, and it ripples with varying curve differentials; extend or compress the skin, and all the gills breathe in and out, all at the same time.

“At that point there were a range of acceptable solutions for the stadium’s form,” explains Akos.“We weren’t enlisted to make a final model, rather to develop a custom design tool.”

Akos and Parsons employed a new strategy on the Monterrey project that is proving to make project-specific design tools more effective and easier to use than ever before.

Tweak Machine:   By varying a few values in Grasshopper, architects at Populous can manage subtle changes to the articulation of the stadium’s curves.

Tweak machine

Ordinarily, Akos and Parsons could achieve a flexible Rhinoceros model through programming alone.  This time, however, they tested out the newly released parametric module for Rhinoceros called Grasshopper.

“Whatever we can do in Grasshopper we could have easily done in RhinoScript,” explains Akos.  “The difference is that Grasshopper now gives us something we didn’t have before.  Grasshopper is operating within a visual programming paradigm, where you can see the logic of the relationships all at once.  The speed and fluidity of engagement with Grasshopper becomes very interesting for a designer.  You have this quick visual feedback of each programming action that you don’t have with code.”

Insider's View: The visual interface in Grasshopper allows designers to change the model’s programming without knowledge of scripting.

Grasshopper creates a middle ground between the 3D model and the logical rules that describe it.  The Grasshopper interface, which resembles a 2D wiring diagram, displays each individual modeling action as an object (a flowchart-like rectangle), linked to other objects containing parameters, like widths, heights, and radii.  Users can change the shape of the 3D model by locating a parameter object in the diagram and typing in new numbers.  Or, as Mode did for Populous, a user can add in graphic sliders for a range of values, or toggle-switches between two fixed parameters.
Because of this interface, parametric features in Populous’ stadium design tool are intuitive to locate, understand, and operate.

“Most offices we work with professionally are already using Rhino, so we can bring them into an environment with which they are already very familiar,” says Parsons.  “Grasshopper is great for clients because it gives them multiple ways to interact with the metrics.They can choose tools in the 3D scene to change forms, or they can adjust values through the diagram.”
Just by spending a few minutes playing with the variable features, Populous’ designers were able to identify which objects controlled which curves on the stadium’s surface.  “They can see in real time how different changes are trickling down through the design and re-organizing other features.  They can sense the different relationships and associations in a very material way.”

A new approach to parametric modeling

There have been of course 3D software centered around parametrics.  A major problem with these parametric modelers was they didn’t particularly lend themselves to intuition.  If you did not build in the parametric controls yourself, it was hard to figure out which features were adjustable, and how to access them.  To make matters worse, if you wanted to adjust a feature that was outside the parametric scheme, you might lose the time-saving advantage by having to deconstruct and reconstruct the model.

With a visual layout of the parameters and more user-friendly controls, Grasshopper manages to sidestep these old problems, opening up new collaborative possibilities.

“Grasshopper allows access and a level of understandability that we have not found in any other software in our field,” says Parsons.“It is very different from much of the parametric software that is out there because of the visual programming environment.”

monterrey03m1

Custom design tools for development and analysis

According to Parsons and Akos, Populous has used their flexible concept model through four months of development work, varying the stadium’s form to match up against the matrix of real-world constraints.

“The stadium was the first application of Grasshopper on a real building-scale project.It was a bit of trial and error,” admits Akos.  Much of Mode’s time on the Monterrey project was not so much building the model, but assessing the needs of the client and determining what variable capabilities the model needed.  As the stadium development goes on, he sees even more potential for shortcuts than he did on the outset.

“Another useful application for the same model is to program it to generate drawings in real time,” he says.“For example there should be a section drawing at every rib; there are 72 ribs of the stadium roof, so if that could be automated, that would greatly simplify the job.”

Meanwhile, use of Grasshopper has entered into many other new Mode programming projects.

“One thing we are looking into now is actually building some analysis into a Grasshopper model so we can work through surface subdivision, planarization, analysis in terms of color shading, and such things as solar gain,” says Parsons.

Given the fact that the first draft of concept rarely is the one that is actually built, custom design tools may soon become a more common occurrence, now that there is an accessible platform to support them — and a design office that specializes in creating them.

About Studio Mode

Mode is a design office that leverages computational expertise through design research, teaching, and consulting.Mode utilizes diverse methodologies including code, associative and relational strategies, as well as digital fabrication in the production of material organizations and the formation of space.Mode is located in Brooklyn, New York.For more projects, please visit: www.studiomode.nu.

About Grasshopper

For designers who are exploring new shapes using generative algorithms, Grasshopper™ is a graphical algorithm editor tightly integrated with Rhino’s 3-D modeling tools. Unlike RhinoScript, Grasshopper requires no knowledge of programming or scripting, but still allows designers to build form generators from the simple to the awe-inspiring.For more information, please visit: www.grasshopper.rhino3D.com.


Remixing in Grasshopper

Noiz / Architecture pushes generative modeling to new heights

by Brett Duesing

One of Keisuke Toyoda’s recent experiments in generative modeling “samples” a work of another: the Beijing National Stadium by Herzog & de Meuron.  His rendering shows the Bird’s Nest of last year’s Olympics strapped down by what appear to be tens of thousands of steel cables, which shoot up to over twice the height of the stadium roof.

Toyoda doubts that the architect would mind the re-appropriation as a creative exercise.  “In their early days, H&deM did a sort of similar thing, a photo collage of an addition on top of Tadao Ando’s building,” Toyoda recalls, “so I am sure they wouldn’t complain about us using their image for a remix.”
16Toyoda is one of the founding partners of the Toyko-based Noiz/Architecture, Design & Planning, a firm whose name also invites a comparison to the world of audio.   According Toyoda, the connotation was intentional. Bold debuts of musical styles, whether a ballet by Tchaikovsky or an album by Metallica, have always been called noise.  In the same spirit, the designers at Noiz look out for new 3D forms that challenge the conventions of its audience.

The remixed Bird’s Nest seems so novel — so noisy — because its textures are unfamiliar.  The word whiskery is not often ascribed to buildings.  The image is also an example of how a small conceptual shift in 3D modeling is now producing a mother lode of innovative forms for studios like Noiz in search of the unexpected.

Shapes of a new generation

Surprisingly, Toyoda only had to model one strand to generate the overwhelming intricacy seen in the remixed Bird’s Nest. This was achieved in Grasshopper, a new plug-in for the 3D NURBS modeler Rhinoceros.  Grasshopper splits the view of a 3D composition on to two different conceptual levels: the familiar 3D visual model next to a display of the logical model of the design.

This interactive history tree allows Toyoda to repeat modeling actions while varying them.  He can easily set up geometric changes according to one shape’s relationship to another.  For instance, he can instruct a strand to bow slightly when tilted in respect to a ground plane to mimic gravity.  He can replicate one strand over a dense grid of points to make a field of 25,000.    He can change this flat grid to rolling ground by plugging in a curvilinear surface.  “Originally, we tried out several 3D surfaces to vary the normals of the strands,” he says.  “I just thought it might be interesting if we use the Birds Nest and add in a realistic context.”gh-rgb1

This automation power has long been available to programmers, but scripting was a long and tedious affair that was too far removed from visual feedback.  With the Grasshopper interface, designers with no programming experience can play around with the logic just as easily they would the 3D model.  Composition then jumps up a structural meta-level – not just drawing shapes, but assigning behavior to shapes.

“This technology has a lot of undiscovered space to stroll around in,” Toyoda says.  “One of the advantages of the software is the ability to model on the fly without having to be a total techie. Since none of us is really a ‘computer person,’ Grasshopper’s interface fits really well for us.  It allows us to do programming with more intuitive understanding, without really writing a script.”

Molecular remix

The Birds’ Nest remix was the end point of that particular experiment, but others become the creative starting point in real architectural projects at Noiz.

Another experimental inspiration was the spirogyra, a kind of microscopic green algae known for its helical structure and luminous green color.  Not long after Noiz designers re-generated the form in Grasshopper as a modeling puzzle, the team found a home for it as a dominant motif for the Hongqiao Office Building (HOB).  Green-tinted spirogyra forms act as vertical supports and carriers of the ventilation system.

“The HOB is sited at the corner of an industrial park, so it had to fulfill the role of a landmark for the whole development and express the futuristic as well as environmental themes as much as possible,” Toyoda explains. “The spirogyra just seemed to fit this purpose.   And, because this site in a suburb of Shanghai tends is a dry and dusty atmosphere, the green color and organic forms add some natural vitality.”

Crucifix remix

The Noiz team developed another project, the exterior of the GoodTV headquarters, almost entirely in Grasshopper. At night, the Christian TV station and an urban church in Taipei, Taiwan, transforms into a four-dimensional light show.  The wall facing the highway features a field of glowing antennae of various lengths. A three-dimensional surface and the outline of the cross are slowly revealed to passing motorists.

“The overall presence of a cross is meant to be very vague and ethereal, like a mist in the air,” says Toyoda, who took influences from contemporary artists like Jim Campbell and Michal Rovner, whose images are kept intentionally blurry or ambiguous.

Chasing the unexpected is the standard course at Noiz, as generative modeling is fast becoming a permanent fixture in its process.  The design team now is in the habit of remixing of their initial ideas.

“Using Grasshopper, we can build a design-process model to produce what we need in actual design, then modify the process model to see what kind of variety we can get,” Jia-Shuan Tsai, Toyoda’s partner explains. “We try several options to see if there would be anything we didn’t expect originally. Sometimes this newly found path can lead you into a whole different area.”

About Noiz

New Forms of music in their infancy has often been taken as noise.  The name of Noiz / Architecture, Design & Planning takes its cue from developments in music history, as an everyday reminder of the firm’s commitment to unique and insightful design solutions.  Founded by Keisuke Toyoda and Jia-Shuan Tsai in 2006, Noiz brings together their joined experience in institutional, commercial, and residential design in Asia and the United States.  For more examples from Noiz, please visit: www.noizarchitects.com.


Grand Designs

nightview

Singapore casino project maintained in a single master model.

by Brett Duesing

Sometimes aesthetics and execution come together to pay off big. In May of 2006, the architectural firm of Moshe Safdie and Associates won the biggest design competition in its history. The city of Singapore had selected the firm’s design proposal for its very first casino, the Marina Bay Sands integrated resort.
“Big” may be too small a word for the award.

“This is a very large project. It’s essentially a city,” explains designer Jaron Lubin, who was part of the design process from the beginning. The Marina Bay Sands development will spread across a six million square-foot footprint, containing casinos and hotels, a 54,000-capacity convention center, an Art/Science museum, a mall, two large theaters, and six signature restaurants.

When the resort opens in 2009, the operation will employ an estimated 10,000 people. According to official reports, the budget for construction of the international entertainment mecca tops out around £2 billion.

For any firm, winning a bid that big is a jackpot. Since the acceptance of the proposal, Moshe Safdie & Associates has doubled the size of its staff in its Somerville, Massachusetts office.

To ensure the on-time delivery of the massive submission and to keep track of all the design output, the team tried a somewhat different approach to project management. The designers’ strategy was to maintain the entire project in a 3D master model. “We started to develop our 3D models right away,” Lubin explains.

The design team modeled the essential forms in a product design software called Rhinoceros.

“Halfway through the competition phase, we had still maintained a coordinated 3D model. This allowed for an easy translation to 2D formats.”

The Rhinoceros modeller is a favorite 3D design generator for industrial art projects large and small because of its powerful NURBS engine, which allows designers to easily create intricate curves, organic surfaces, and sculpted textures. Curvilinear elements like these can be seen as a unifying motif throughout the Marina Bay Sands interior and exterior designs.

day-view

For the team at Moshe Safdie & Associates, Rhino gave the additional advantage of flexible export, which could convert all the curved shapes faithfully to other 3D and CAD-related formats. “The key to using Rhino for us was that there was such an easy exchange between other software platforms, so we could have many modes of simultaneous production. This enabled our competition team to act more efficiently and create a higher quality product in the end,” says Lubin.

From the 3D master model, sections of the design were exported to whichever software was most appropriate for the task: to develop further details, analyze the structures, and prepare the final visual presentation in the form of renderings and physical models. For instance, the master model exported the basic linework for 2D base plans, sections, and elevations. From there, other designers could further develop details using AutoCAD, Adobe Illustrator and Photoshop.

The firm relied on several outside parties for consultation on structural engineering and wind simulation, and for professional rendering services to create the final photorealistic images. Analysts received DXF exports of the master model to be used in their own 3D systems. The 3D model in its entirety was sent to the rendering and animation firms through a special NPower plugin, which converts 3D data from the Rhino modeler to 3ds Max.

While the outside firms rendered the Marina Bay Sands complex into the backdrop of the Singapore skyline, Moshe Safdie & Associates’ in-house model shop cut all the scale model parts. Here the team extracted STL files to create 3D components through a Z Corpcasino interior rapid prototyping printer and automated 3-axis CNC mill. The master model also exported 2D outlines that were made compatible with the model shop’s laser cutter by utilising a multitude of widely available plug-ins and scripts.

“The trend is that more people are using 3D programs like Rhino to link the 2D work from the 3D model so that there is less redundancy in re-drawing what has already been made,” says Lubin. “The 3D work generates the 2D work, and vice versa. We tried to do that as much as possible on Marina Bay Sands. Given the fast track of the project and the amount of models that were required for the competition, we developed techniques to take advantage in this way. We reduced redundancy and kept things tightly managed through a central model.”

The extra detail required for the contest submission led to a much more comprehensive initial design, one which pleased the Singapore officials to such a degree that they have accepted the results of the competition phase as the official guidelines for future development. “Because of the timeline, there will likely be minimal aesthetic changes between the submitted design and the final product,” Lubin surmises.

After a brief celebration of on May 26, the day the architectural jackpot was announced, the staff of Moshe Safdie & Associates prepared itself for more work – about three years more work – to make the Marina Bay Sands a reality.

“Everybody has been really excited about this project and what it means for the office,” says Lubin. “It has set a high standard for all the work that we’re doing, and we’ve been very happy with the output.”

# # # A version of this story was published in AECMagazine.

strong>About Moshe Safdie & Associates
With offices in Boston, Jerusalem, and Toronto, the award-winning Moshe Safdie & Associates have built signature structures all over the world that showcase the best in creative architectural design. To view the completed projects of the
practice, visit: www.msafdie.com.


Q&A: Pushing Visual Limits of 3D

cath

In their spare time, husband-wife visual effects team uses modern photogrammetry to create stunning, lifelike renderings of historical Seattle landmarks

In 1905, Catholic Bishop Edward J. O’Dea laid the cornerstone on what would become St. James Cathedral in Seattle, Washington. More than 100 years later, as the structure still stands its ground, the husband-wife design duo of Matt and Danika Wright have pushed the limits of modern design technology and recreated the intricate beauty of the historical landmark in stunningly lifelike 3D renderings.

The Wrights are partners in Mattika Arts, a firm offering 3D modeling, rendering, illustration and photography services. As a visual effects team, they have created high-resolution 3D environment models for more than 11 movies, including Harry Potter, Master and Commander, XMEN2, Daredevil and Day After Tomorrow, as well as for projects in the video-gaming industry.

The pair didn’t create the St. James Cathedral renderings for profit. They simply had a personal wish to challenge themselves as 3D artists. While they were at it, they also modeled Seattle’s Mariner building and the Seattle skyline in a similar manner. Technology writer Brett Duesing spoke with Matt Wright about why he and his wife undertook these projects and how they achieved the amazing results.


A lot of married couples might take up something like tennis in their free time. You and Danika chose to replicate St. James Cathedral.

Matt Wright: [laughs] Yes, all these projects we worked on in our spare time on evenings and weekends around our regular work schedules over the course of a year. The purpose was not related to any business end. Instead, it was a challenge to ourselves to push what we could do as 3D artists. We have worked in the film visual effects industry for a number of years, and also the video-games industry. We wanted to see how far we could take some current technology to produce the most accurate, lifelike work. Photogrammetry is a technique we were familiar with professionally, but we hadn’t had the opportunity to explore all of its possibilities. We wanted to see if it could be applied on a very large scale and include a very high level of detail.

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Photographs of Seattle’s St. James Cathedral turn into accurate 3D measurements inside PhotoModeler. The key points in the 3D structure and the position of the cameras are then exported into Autodesk Maya for rendering.
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The wireframe model over one of the original photographs of the cathedral. “Shots like this help us gauge the accuracy of the project, and show areas that need to be refined,” says Matt Wright.
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Final renderings of St. James Cathedral depict lifelike detail, created by Matt and Danika Wright, using Autodesk Maya.

Which software did you use?

We used photogrammetry software called PhotoModeler [from Eos Systems] to capture both the large-scale 3D measurements of the overall structure and the very fine details of the ornamentation. Essentially, whatever is in a photograph is measurable. PhotoModeler aligned our camera positions in 3D space and also helped generate 3D reference points. This camera and point data was then taken into Maya [from Autodesk], a modeler we use a lot in the film and game industry, which is good at handling very large, complex scenes. Inside Maya, we built all of the geometry, based on the data generated from PhotoModeler.

Why photogrammetry?

Whenever you’re recreating a real setting, you have to decide on what technology to use to measure the sites in 3D. The most obvious is a tape measure; however, this is rather impractical on such a large scale. Another option might be laser scanning; however, this would have been too intrusive on the sites, especially in the case of the cathedral, because of the size and amount of equipment we would have to take to these places.

Photogrammetry seemed like the perfect solution. All you need is a camera, and you can survey the sites quickly. About 20 minutes in the cathedral yielded all the photographs required to model the entire interior. Photogrammetry, when used correctly, also yields great accuracy, especially for architecture. The cost is also a lot cheaper, since it only requires the software and a pretty good digital camera — which makes it far more practical for a couple of 3D artists like us doing a little experimental project on the side.

Was it difficult deriving the 3D geometries from photographs?

Not really. First you take your camera — we used a Canon EOS 10D, which is a regular digital SLR camera — and you run it through a few calibration processes within PhotoModeler to get accurate information about the lenses and distortion and all the camera’s interior parameters. These camera specifics are how PhotoModeler can calculate the actual distances.

After that, it’s nothing more complicated than taking a few pictures of what you want to model. You download those pictures to your computer and pop them inside PhotoModeler. Given the pictures and also the camera’s technical parameters, PhotoModeler interprets the scene in three dimensions.

You start by matching up points between images — pick the corner of a chair in one image and the same corner in another image, for instance. You add maybe 20 matching points over the images. Doing that to a minimum of three images, you’ll start seeing this 3D scene emerge in PhotoModeler. The software will also work out the camera positions (the point where you took the picture) relative to each other, which comes in handy later when you put the final model together in Maya. All of this information can then be exported to Maya, where you have the correctly aligned cameras/photos and all the reference points that you marked in 3D. From these, you can start modeling your scene using the tools inside Maya.

All these models have so much detail — millions of vertices in one scene. In reality, you said your 3D depiction of St. James Cathedral took the equivalent of about three months of solid work to create. What were some of the shortcuts you used?
Looks can be deceptive. We did reuse some of the components throughout the model, copying the pieces, like the crown molding on the columns, and repeating them around the nave. Architecture is all about repetition, so there’s a lot you can copy. Some of the arches through the cathedral are the same, just different sizes, so all that is required is some scaling of the base curves. You can copy them over and make the modifications to it to make them fit. And, obviously, if you have 500 chairs that are all the same, there’s no point in building each one.

One of the interesting problems we came across with all these projects: We are not dealing with brand-new construction, where everything is 90 degrees and just about vertical. This is old architecture that has settled over time. Copying details was good, but it took a lot of tricky alignment because walls aren’t vertical and not perfectly square. The Mariner building represented about two months of work, and it turned out to be a lot harder than the cathedral because the structure had some real settling problems and hardly any 90 degree angles whatsoever. That’s when it became extremely time-consuming. You weren’t working on any flat plane to which you could align a modeling grid. Otherwise it would have been much quicker.

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Seattle’s Mariner building, with a wireframe model superimposed over an original photograph.
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A final rendering of the Mariner building in Autodesk Maya. Matt Wright comments about the photogrammetry process: “One thing that we learned very quickly was that photogrammetry is very different to regular photography, or even photography for texture/reference work. You constantly have to think about angles between camera shots, what you have in frame, making sure there is enough detail and depth in the image.”

Do you think that staying true to the actual building measurements — flaws and all — made a difference in the final rendering? Was it worth the extra work?
In my opinion, yes, absolutely. We didn’t want to make the building dead-vertical with proper 90-degree corners. That’s not what that building was about — it isn’t that way in reality. Visually, it’s perhaps a little more of a subconscious thing. In the rendering, the walls may look perfectly vertical and the corners look perfect. But if everything was truly squared up, it probably would not look quite as realistic.

How did you deal with the enormous size of the 3D models? Did that present any limitations?

That’s why we used Maya for the final modeling. Although you can model objects very well in PhotoModeler, Maya is designed for dealing with very complex scenes and huge amounts of geometry. If you work smart and keep your work organized, Maya can handle an almost unlimited amount of data. There was really no problem in that respect working on this whole thing.

One way to work smart in Maya is to choose your geometries beforehand — whether you’ll model a section with NURBS surfaces, subdivision surfaces or polygons. This helps to manage the file sizes. We tried to keep everything in its original geometric form, right up until rendering. Traditionally at render time, you would convert the NURBS to polygons, and a lot of people would convert them to polygons long before that point. We actually kept everything in its place until the end, just to try to keep file sizes down.

Wherever possible, we tried to use instancing so at any one time only one full copy of a complex piece of geometry was stored in memory. So we didn’t have the memory overhead for 200 column tops. Each column top might have 110,000 polygons. That alone, copied around the scene by itself, would be millions and millions of polygons. With instancing, we only need one version in memory.

figure
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The downtown Seattle skyline, captured by photogrammetry and rendered as a 3D model (top), then textured (bottom). Matt Wright says, “Modeling an entire city is a future project that we have. The downtown skyline was a bit of a test to see how far we could go. It would be interesting to see how far you can push this technology and how much time it would take to reproduce something as massive as a city.”

PhotoModeler has been used for a wide variety of applications — industrial and scientific measurement and reverse engineering — but not so prominently in the animation industry. Why did you turn to this solution?

We actually started off using another product but discovered that it didn’t take into account all principles of lens distortion and principal point of the camera — two factors that play a big part in the accuracy of photogrammetry. If your photogrametry solution isn’t completely accurate, by the time you’ve added 10 or 15 cameras, the end solution won’t solve, and you’ll have no idea why.

That’s when we found PhotoModeler, and right off the bat the calculations were a lot more accurate. It has amazing tools for analyzing error, and it has an incredible feature called Idealize, which corrects all camera distortion in your images and recalculates the scene directly. Maya and most other 3D software cannot deal with distortion, so you have to remove distortion from the images before taking them into your 3D software. PhotoModeler is one of the first tools that come to mind whenever we have to recreate architecture now, or recreate anything.

# # # A version of this article was published in CADalyst.

About Eos Systems

Eos Systems Inc is the developer of the award-winning PhotoModeler software and is the leader in versatile close-range photogrammetry solutions. PhotoModeler provides an easy and affordable solution for measurement or reverse engineering of objects into 3D CAD through the use of photographs. The software is used by thousands of companies specializing in crime and accident reconstruction, archeology, architecture, engineering, surveying, film and video animation.  Eos Systems is headquartered in Vancouver, British Columbia. For more information about Eos Systems and PhotoModeler, please visit:  www.photomodeler.com.


Slipstream

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Sungrace builds SW automation for RWDI’s sky-high models

by Brett Duesing

If your architectural project scrapes the atmosphere, you will likely need the rarified services of a company like Rowan Williams Davies & Irwin (RWDI). This Toronto-based consulting firm has provided wind engineering, environmental air quality and noise management services for many of the largest architectural projects in the world, from Taipei 101 in Taiwan (currently the world’s tallest building) to Burj Dubai in the Middle East (which will soon take over the title) to Daniel Libeskind’s Freedom Tower at New York’s World Trade Center site.

For these substantial projects, RWDI uses a SolidWorks 3D electronic model to output a series of recommended design wind pressures. The company simulates and analyzes many of the environmental effects on superstructures using a variety of tools, including wind tunnel testing, and computational fluid dynamics (CFD) using Fluent and a custom-designed program called VirtualWind. Certain studies, like the wind-tunnel pressure test, require a physical scale model of the proposed building to be constructed, along with the surrounding terrain and cityscape.

“A pressure study looks at the effects of the wind on the exterior envelope of a building in the context of its geographic area. These wind effects will be different in a crowded downtown area than if the structure was built out in the middle of a field. Often times you’re dealing with very complex wind flows,” explained Matthew Browne, RWDI wind engineering specialist. “The wind tunnel testing gives very accurate, project-specific design information.”

A detailed model of a building ready for the wind tunnel test. The building’s surroundings are handcrafted using rigid foam.

RWDI constructs its study models using rapid prototyping technology (RP) or stereolithography (SLA) from 3D Systems, which produces a model via the layer-by-layer curing of photosensitive resin. The painstaking part of the work used to be performed manually. Modelmakers had to drill holes on every surface of the model to install all the pressure sensors, or taps, needed for the wind tunnel test.

RWDI sought a way to automate the installation of pressure taps with its eTAPS, or “electronic taps” program, so the model parts could come out of the SLA machine with holes perfectly spaced for testing.

“Typically, we have to install several hundred pressure taps in a model. The eTAPS project is a way of using our RP technology to also incorporate these pressure tubes in the physical model, rather than doing it by hand with a drill and glue,” Browne explained.

Through its in-house R&D department, RWDI developed software to locate the placement of pressure taps over a given building model at optimal spacing. To reach into SolidWorks and automatically change the geometry of the actual model, RWDI enlisted the help of Sungrace Software.

“SolidWorks provides a great deal of functionality in its API that permits geometric analysis and construction of these kinds of complicated features,” said Mark Yerry, the senior developer at Sungrace who led the eTAPS project. Automatic conversion of positional coordinates into the solid model features is a conceptually simple task.

“In many cases, it’s straightforward,” Yerry continued. “A tap will fit and have enough space behind the wall to accommodate the pressure tap. For the ones at the edge of the structure, or where there is a cluster of many in one section, we had to develop a more sophisticated set of tools. The most challenging aspects of this project involved the development of a few key algorithms.”

For example, some taps needed to slant upward or downward to prevent conflicting with other sensors. “We programmed the Multi-Point Tap design tool to create the custom paths for the more difficult tap placements. So rather than simple holes, these taps follow a path that the user specifies,” Yerry said.

The eTAPS add-on appears as an extra menu inside SolidWorks, which gives RWDI modelmakers the means to automate the creation of simple pressure taps in the virtual model, the Multi-Point Tap tool for more congested areas, and additional tools for mold fixturing. The tools that make more complex paths still require some human decision making inside SolidWorks, but the prep time to fully instrument a skyscraper is cut to a tiny fraction of the old drill-and-glue technique.

Automating these modeling tasks has increased efficiency at RWDI by about 15 percent, which in turn increases the company’s capacity to perform pressure studies on a monthly basis. Browne commented, “With the new eTAPS we are able to cut a significant amount of time out of a typical project.”

The eTAPS SolidWorks add-on is proprietary and not for sale, and given the highly specialized work of RWDI, few others would need it. However, as firms involved in 3D manufacturing and architecture look for new ways to improve efficiencies, many may soon seek a customized modeler of their own.

# # # A version of this article has been published in CADalyst.

About Sungrace

Sungrace provides technology driven engineering and engineering software development services to customers across the globe. We specialize in several mechanical and civil engineering domains and provide solutions to the entire Extended Engineering Enterprise. This includes the OEMs, Owners/Operators and their engineering and software suppliers.  During the past two decades Sungrace has worked with over 200 customers from large Fortune 500 organizations to small and mid-sized companies spread across the globe including US, Canada, UK, Germany, Belgium, Denmark, Italy, Norway, Denmark, Japan and India.  For more information, please visit:  www.sungrace-group.com.


Curves Without the Cost

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Wood Builder AWI adopts 3D in construction processes

By Brett Duesing

Advancements in 3D design tools have given manufacturers tremendous productivity gains over the last two decades.  Automotive development, for example, is nothing like it was twenty years ago.  In this industry, not just styling and engineering revolve around 3D data, but downstream factory processes have evolved to take advantage of the efficiencies that 3D technology offers.

One would think 3D CAD should provide the same benefits to the field of architecture and construction.  Architects would have a wider palette of forms for expression – curvatures and non-rectilinear textures; contractors would have clearer visuals and less confusion, delays, and overruns when erecting complicated structures.

But for the most part, these benefits have not emerged.  Although designers can easily model fantastic forms in 3D modelers, the technological advancements soon meet up against human resistance.  Personnel used to the traditional methodologies of architectural and construction management – engineers, subcontractors, inspectors – even the AIA itself – all expect contract documents to be delivered in the form of 2D drawings.

Experiments in form sometimes require architects to do the extra footwork, mainly plotting 2D drawings derived from their original 3D model.  And, describing complex geometries through 2D views invites confusion.  According to the website of Gehry Technologies – the software wing of Frank Gehry’s firm – poor data coordination with the field results in cost overruns of 20 percent.  Beyond redundancies inherent in the status quo, reducing a form to 2D leaves out the great advantages of modeling.

“In the world where changes in the technology may take only a year or two, but where changes in construction can take a whole generation – 35 years or so, we see the huge leap of faith it takes for designers and owners to push these ideas,” says Richard Herskovitz, architect of Architectural Woodwork Industries (AWI).

What if all the processes of construction were based around the 3D model?  In contrast to the inertia of the rest of the industry, Philadelphia-based AWI is a subcontractor that has chosen to embrace 3D technology.  Its advocacy of a 3D-centered workflow is how the firm achieved the curved woodworking on EMPAC’s concert hall at a cost that rivals cubes.

EMPAC was designed by Grimshaw Architects, and modeled in Rhino; Davis Brody Bond are the local architects of record and coordinated all of the consultants, provided the Contract Documents and supervised construction.

The firm’s methodology is a glimpse of how construction could be, and, given that the overall approach has more efficiency and more common sense than the traditional route, there’s no reason to believe that it is not what construction will be in the future.

Optimizing the power of 3D on- and off-site not only makes building curved surfaces possible, it makes building faster, cheaper, and more accurate.

The EMPAC Experiment

The white steel frames and floor-to-ceiling glass panels on the Experimental Music and Performing Arts Center (EMPAC) seem typical in a modern campus building, but a glance through the windows of the new event center in the Rensselaer Polytechnic Institute reveals the shell of a three-story auditorium, rounded on all sides, top to bottom.  The hive-like interior structure is entirely covered in a crosshatch of smooth wood panels, furthering the auditorium’s surprising organic presence.

Designed by Grimshaw Architects, EMPAC uses curvilinear surfaces as its centerpiece.  The design is emblematic of the new experiments in sculptural forms and texture in large public building projects.

When the main contractor, Turner Construction Company, awarded the bid for the EMPAC’s wood paneling to AWI, the woodworking specialist had an unusual stipulation.  Coordination between AWI and all other subcontractors would use the original 3D design model as its shared point of reference.  Instead of the expected 2D drawing the trade had relied on for generations, the concrete and structural steel subcontractors received a copy of modeling software, some brief training, and the 3D auditorium design divided into construction phases.

“The open process where many disciplines or many subcontractors share digital information, come together on site or in the office to coordinate is a huge change,” says Herskovitz.  “This reinvention of process is, as a friend put it, ‘a social experiment.’  It is not so much about the technology, but about how it’s implemented.”

Bentwood requisites

The reason for AWI’s close relationship to 3D modeling comes in part from the needs of the material itself.  The architects and engineers adopted a 3D mentality back in 1991 when computer-drafting programs first appeared.  At the time, woodworking machinery from Europe began to employ computerized drivers, and specialty programs aided in many standardized cabinetmaking tasks.  The equipment was highly accurate, much more so than the manual set of equipment.  Ever since, the firm has constantly kept pace with new 3D technology, applying the latest innovations to the needs of the industry.

Its expertise has translated into AWI taking on increasingly difficult large-scale bendwood interiors, often working with the designer from conceptual design through construction.  AWI has developed its methods over the course of several major sculptural panel projects such as Philadelphia’s Verizon Hall at the Kimmel Center, and the interiors of the Boston Convention Center.

In curved wood designs like these, superior accuracy is needed when hanging the panels.  If the underlying structure strays too much from the planned dimensions, the subtly curved cedar planks will fail to fit together.

“As wood is a material which expands and contracts about an eight of an inch for every eight feet, we need about eighth-inch tolerances.”  These margins for error are about four times tighter than what is seen at typical construction sites.  Framing for housing, for example, might vary around a half-inch.

In AWIN’s quest for woodworker’s accuracy, the firm discovered processes like digital manufacturing and robotic transiting, as well as the benefits of planning construction phases in 3D.  These new methods have also produced some unexpected side effects: bringing down costs and speeding up building processes.

‘Process’ is more important than ‘program’

The first step in constructing EMPAC’s distinctive shape is to ensure accuracy in the 3D model.  The project architect, William Horgan, modeled Grimshaw’s concept in a special industrial design modeler Rhinoceros.  Rhinoceros uses mathematical equations called NURBS (Non Uniform Rational B Splines) to construct surfaces, and so can calculate any point on a complex curve with pinpoint accuracy.

“This NURBS engine capability for analysis and extremely high accuracy on curves is limited to a very few applications only,” says Herskovitz.

>Rhino was used as a common platform for coordinating the steel, concrete, ductwork and outer skin, and the live model projected and used to coordinate these systems in weekly meetings. The inner Hull concrete wall formwork was modeled in Rhino by Perri Forms in Germany and inserted in the master model for checking purposes.

Clients embarking on 3D construction should not be overly concerned about which modeler is used to create the initial design, he says.  No matter what design files it receives from the client, AWI can easily import the geometry into a full NURBS environment.  Rhinoceros also fluidly imports and exports 2D geometry in common formats used by AutoCAD.

“Programs like Rhino offer designers a better way to study forms and to create those forms accurately.  Rhino can read most other files accurately, and gives a designer a means to integrate their other work in Rhino as a neutral environment.”

Collisions were manually detected using Rhino, and provided the visualization used to explain issues in Team meetings, and as a logistics tool for the Hull panels. Specific collisions were identified and solutions found jointly, rather than in a lengthy a RFI process. Decisions were made jointly and committed to meeting minutes, saving weeks and countless hours of staff time.

Here the extension of the inner acoustic wall through the outer steel, and the overhang of the slab were seen and corrected without RFI, and via a weekly meeting centered around the model. Even the lack of attachment of a steel gusset was visualized in this same way. These common problems would not be found using collision detection software, but were found by visual inspection.

Rhino was used to extract geometric information and send it to Radius Track to bend the studs and track in Minnesota. Each double curved surface of the wall panels was divided into equal spaces in order to develop the curvature of each stud and track making up the panels. Those models were then sent digitally and extracted into a special program which drives the bending equipment.

The advantage of the Rhinoceros system is it allows AWI to break up, curved geometries into discrete parts, number them and organize them for later stages of the project.  For the EMPAC auditorium project, a single engineer, AWI Project Manager Ron Evans, refined the model and exported particular shapes and arcs into structural analysis programs.  Further, the modeler enables the design model to be broken down into component parts, numbered, and organized for later construction.

Digital Manufacturing

One of the more innovative methods of AWI’s new approach lends itself from the field of manufacturing.  After Evans subdivides the designer’s 3D concept into smaller components within Rhino, the 1200-seat concert hall skin resembles more of a series of small manufacturing projects.  Just as manufacturers would fabricate prototypes of chairs, AWIN produces its building components in a factory environment.

The studs were then assembled using drawings derived from the panel models allowing Eastern Exterior Wall Systems assemble them accurately off site, and to deliver them in the proper sequence.

A full sized mockup of a portion of the most curved area and the portal were used for approval by the design team and the owner.

By extracting the surfaces of the support “blades” from a Rhino model, fabrication information was provided in AutoCAD to the metal fabricator to drive a CNC laser cutter to cut the blades.

As a consequence of this automation, the fabrication labor costs are not much more as if all the steel panels were all curved identically. The computer drivers simply read each panel’s geometric instructions and the machine cuts, drills, or crimps the materials accordingly.

Off-site fabrication is nothing new.  The 1972 construction of the New York City World Trade Center involved factory production of identical steel grids that formed the exterior lattice.  What is new is that today’s 3D computerized cutting allows all the parts to be unique rather than identical, enabling the construction of a curved surface at a giant scale.

X, Y and Z at the Building Site

To maintain the exceptional accuracy gained in shop fabrication, AWIN must hang the panels on the concrete and steel substructure according to the same standard.

This is achieved through the use of robotic transits.  Similar to laser-measuring equipment already common to the construction site for preliminary surveying, a robotic transit can be programmed with the 3D monitoring points from the NURBS model.  Robotic mechanisms move the laser pointer by remote control, eliminating the need to enlist an extra worker to operate the station.

Rhino was used to extract the location of points for placing the panel support “blades” and then transfer the information to AutoCAD for the surveyor to prepare their input for the transit. The robotic transit located the Center Line, height and distance from the steel structure so that angle irons could be welded in place correctly.

“A robotic transit has the ability to locate a point using a combination of EDM, or electronic distance measurement,” explains Herskovitz.  “If you know the vertical and horizontal angle and the straight line distance required, you can layout that exact point in space.”

The technique is the final step in the continuum of three-dimensional processes.  The construction site is now linked to the virtual model.  In effect, an enormous x-y-z grid is overlaid the project location, complementary to the computerized 3D forms.  The result is high-accuracy installation, but it is also cost-effective.  The automated techniques allow the EMPAC panels to fit onto the substructure perfectly, eliminating hours of costly re-work that would normally plague a project of such complexity.

AWI used Rhino to design the special 3D structure in wood for the lower portals, and to cut the shapes for the curved edges out of FR Plywood.

The complex shapes of the upper portals included double curved track and straight studs covered with 22 GA sheet metal to provide a non-combustible back for the wooden exterior.
Though 228 2D assembly drawings were created, the only way for the architects to check the shape and approve the drawings was by inspecting the 3D Rhino model in 3D. Here, the South side bridges needed acoustic separation from the wall of the Concert Hall. Thus proof that the panels had a few inch gap was critical and proved to be correct. In fact, all of the blades and panels fit without misalignment.

Construction Planning Re-invented

The biggest innovation, and biggest challenge in moving to 3D-based construction may not be digital, but social – changing the attitudes and entrenched ways of approaching problems.  To avoid cost overruns during AWI’s paneling stage, it was necessary to have the earlier phases of concrete and steel layout to maintain high standards of accuracy.

“Fortunately for us, Jasper DeFazio, Turner’s Vice President, was a proponent of this approach from the start, and Rensselaer also invested in modeling by having AWI model all of the important shapes to aid in coordination,” says Herskovitz.

“Of course, there was a learning curve for coordination in this way.  First we had to sell the other contractors the idea of using 3D, then there was some education of how to use the Rhinoceros tools in the beginning,” he says.  “But it was important for us that everyone think in three dimensions, and fully understand the critical areas where our work came together.  A virtual building can often visualize conflicts and pose important questions earlier in a project, and that ultimately will save money and time during construction.”

Herskovitz advocates 3D as a means of coordination for all the players in the field in order to more clearly define the phases of construction, and to assign responsibility between owners, designers, and subcontractors.  To win all the benefits of 3D construction, processes need to change, including the traditional roles and duties of each player.

“The digital world has allowed architects to design more complex shapes, but the means and methods for construction are changing too slowly to keep up,” says Herskovitz.  “By centering construction around the 3D data, well coordinated, complex designs are literally able to go from model to fabrication.  It has become difficult to explain what we do, as the lines between consultant, modeler, and contractor has blurred.”

Occurrence of sculpted forms in architecture is still rare, and form remains circumscribed by cost considerations.  “Competitions, usually for public buildings, are the exception.  Art museums, performing arts center, libraries, transportation centers are big business in the architectural world,” says Herskovitz.  “In these cases, form itself is given a budget.  These clients invest in the art form of architecture and invite more innovative designs,” remarks Herskovitz.  The vision for the EMPAC auditorium, however, did not require a dream budget – the bill for the structure was a fraction of what clients typically pay for a high-quality concert hall.  “The owners received a very good deal.”

In these big-budget projects, experiments in technology and technique are tried and tested.  From these, a new set of efficient and innovative construction processes is now emerging.  “Proving the cost effectiveness of the 3D process is what we’re trying to do now,” says Herskovitz.  As the industry learns the efficiency of 3D construction, we will likely see more of it in the future.”

# # # A version of this article was published in CGArchitect.

About Architectural Woodworking Industries (AWI)
Architectural Woodwork Industries, composed of woodworkers with many years of shop and field experience and two trained architects, provides consulting, engineering, project management, budgeting, and scheduling services along with the fabrication, and installation of fine woodwork. Based in Philadelphia, AWIN builders are in the forefront of using 3D CAD/CAM technology to achieve affordable and quality high-concept wood designs.  To view past projects, visit www.awin.net.

About Rhinoceros
Rhinoceros provides the tools to accurately model your designs ready for rendering, animation, drafting, engineering, analysis, and manufacturing.  Rhino can create, edit, analyze, and translate NURBS curves, surfaces, and solids in Windows, without limits on complexity, degree, or size.  Rhino gives the accuracy needed to design, prototype, engineer, analyze, and manufacture anything from an airplane to jewelry. Rhino provides the compatibility, accessibility, and speed in an uninhibited free-form modeler that are found only in products costing 20 to 50 times the price. To see the many diverse products designed with this affordable 3D tool, and to download a free evaluation version, please visit:  www.rhino3D.com.


Topologica

sidra_farview

The SMART team, a software R&D department at UK's Buro Huppold, has developed a method of integrating digital design, analysis, and construction processes. Integrated modeling proved essential for building the complex structure of the convention center for Education City, Qatar, shown here.

A SMART approach to integrated 3D analysis at Buro Happold

By Brett Duesing, Obleo Design Media

As one of the largest engineering consultancies in the world, Buro Huppold crosses continents — with 15 offices throughout Europe, the US, and the Middle East – as well as disciplines, offering its clients solutions to nearly any design, structural, and civil engineering problem.  The firm’s design CV is considerable, including such early achievements like the Pompidou Center, and the Sydney Opera House.  The firm’s size — and its sizable tasks –  has led to its own Research & Development department, which looks for new ways to solve spatial problems.

“My SMART team – Software Modeling Analysis Research Technologies – focuses on the area of very complex nonlinear geometry in modeling analysis,” says Dr. Shrikant Sharma, who leads the group out of BH’s Bath, UK office.  “We’ve developed software which expedites these analyses through our internal research in cooperation with the top UK universities.”

Outside the Box -- More complex architectural shapes  -- like Buro Happold?s elongated curves on Malmö Green house in Sweden -- brings the need for 3D tools to solve geometric problems for engineering and construction.  The SMART team, a software R&D department at BH, has developed a method of integrating digital design, analysis, and construction processes.

Outside the Box -- More complex architectural shapes, like Buro Happold?s elongated curves on Malmö Green house in Sweden, brings the need for 3D tools to solve geometric problems for engineering and construction.

Sharma’s patented software creation for BH, SMART Form, is one example of how 3D modeler can be used to model not just shapes, but to model problems.

Open Architecture

“We use a variety of tools to optimize the process of finding the most efficient structure.  We write software as we need to, and obviously use existing software when it fulfills our needs,” says Sharma.  “But sometimes existing applications can’t answer the questions we have.  Some programs are very generic and we can’t add in certain specifications.”

Part of the philosophy its software developers, McNeel & Associates, was to keep the Rhinoceros modeler an open architecture that third-party programmers could independently develop and sell plug-ins which give users access to enhanced tools for specific for different industries.  As a result, Rhinoceros itself is kept unburdened with too many features, but at the same time adaptable to diverse design specialties from aviation to architecture.

Rhino’s 3D geometries are part of the input for SMARTForm, along with the queries for the particular structural or costing problem.  The Rhino model also displays the output from the SMARTForm analysis.  SMART plug-in queries can survey the 3D model automatically, highlighting surfaces that conform to a certain extent of curvature or angle, or lie a prescribed distance from other entities.

Just as Geographic Information Systems (GIS) query relationships between points, lines, and enclosed shapes on 2D maps, SMARTForm uses topological relationships, along with differential geometry, to map out problems on a complex 3D structure.

sidra-branches-wBuilding A Tree

A recent example of SMARTForm capabilities is Buro Happold’s convention center in Education City, a new 2,500-acre campus on the outskirts of Doha, Qatar.

“Education City will have lots of extensions of foreign schools, some of which are already there, like Carnegie Mellon,” explains Sharma. “They will provide state-of-the-art education to students of the Middle East, and promote the location as an international center of education in the region.”  This massive convention center includes auditorium and committee meeting rooms for major events in Education City.  One of its exterior walls contains a 20-meter-high, 250-meter-long sculpture of a Sitra Tree – an ancient Arabian icon of learning, growth, and stability.

Making the form structurally sound is a job for Sharma and his SMART group, which modeled, analyzed, and optimized the tree sculpture and roof supports. SMART worked closely with the structural engineering team which was responsible for the detailed design and analysis of structural elements. Brian Cole, also based in Bath, led the project within SMART.

treecrosssections1The team begins with the Rhinoceros model of the architect’s free-form shape, which in the final structure will only be the tree’s outer skin. The actual loads will be carried by a substructure of steel members, which is up to the team to devise. The internal support system needs to be efficient in its use of materials and effective in its support at all points.  Because the components will be digitally manufactured off site, the system should keep the number of assembly parts to a minimum.

“We wanted the skeleton to be as close to the skin as possible simply to make sure the structure is efficient and uses the least amount of steel,” says Sharma.  “For the shape of the members, you wanted something that would be as close to a circle as possible but not have a lot of complex connectors, so we chose an octagon.  Also, we wanted the members to conform as much as possible to the center line of the branches.”

SMARTForm was used for finding the center line through the 3D model with a least-square fit formula, ensuring a uniform distance from the skin.

“The result is that we have a minimum of straight segments which are very close to the center line, while not having a lot of bend in the structure.  To make sure there’s a consistent space between the structure and the skin, the orthogonal structure actually tapers in its width as it goes from the bottom to the roof line,” Sharma explains.  “The branches also taper at a slightly different ratio.  A simple mathematical equation based on volume dictates how wide the members will be.”

Treehousing -- The trunk?s metal skin provides the form.   The load of the structure is carried by the centerline members.  BH engineers chose an octoganal shape to approach a circluar form, but which would better support angles at the joints.  Engineers also used thinner sides and hand-access holes to aid on-site assembly.

Treehousing -- The load of the structure is carried by the center-line members inside a steel skin. BH engineers chose an octagonal shape to approach a circular form, but which would better support angles at the joints. Engineers also used thinner sides and hand-access holes to aid on-site assembly.

The varying width of the octagonal steel members give a consistent support throughout the Sidra Tree without tensile warping of the thin skin of metal panels.  The geometric rationalization resulted in an efficient arrangement of solid regular structures that supports the more free-form exterior skin. It also enabled detailed design of the substructure using conventional design codes by the structural engineers.

Plug-ins to cut corners

SMARTForm analysis not only is useful in creating efficient geometry of structural systems, it can also be used to test construction alternatives that reduce cost.  constr-sidra

The outer skin of the Sitra Tree sculpture was to be thin panels made of corrosion-resistant steel.

“The client did not want glass-reinforced plastic, which would be much easier to fabricate with curvatures.  The intent was to build this fantastically complex tree structure from metal, which is a bit more problematic and expensive to construct.  With metal, cost became a significant constraint.”

The design and build team of Victor Buyck and Buro Happold found that a doubly-curved metal panel would cost up to four times to produce than one which is curved in just a single direction.

“A two-curvature panel will be very difficult to fabricate, since the bending, rolling, and stretching of the metal occur all at the same time, so there are a lot more costs associated with it.   Essentially, we wanted to maximize the number of panels that could be described as a single-curve surface, and keep the doubly-curved panels to a minimum.”

Using SMARTForm and the Rhinoceros panel scheme, Sharma’s team could quickly identify the thousands of metal panels by their topological make-up.  In the majority of occurrences, the secondary curve was only slight.  Sharma proposed a design compromise that changed the cost dramatically, while tweaking the overall shape of the Sidra tree almost imperceptibly.  The new panelization consisted of 70 percent of the panels as single-curve components, cutting about 60 percent of the cost of the skin fabrication.

“If you replace many of the original doubly-curved pieces with single-curved replacements, you can barely tell the difference,” says Sharma.  “We could construct basically the same tree-skin form with less complexity, but without loosing any of the character or smoothness of the shape.  There are points, especially at the branching joints, where you obviously need a double-curved piece.  We replaced the design driven by a curvature-based definition in SMARTForm which followed the flow lines of the tree shape.”

Digital fabrication

“Another consideration was transportation,” says Sharma.  “The entire tree was being fabricated in Malaysia. We didn’t want a lot of small pieces, and we wanted a close fit for the substructure when it was to be assembled on site. Another constraint was the assembly itself, not just initial construction but the need for a long-term access and maintenance strategy. We made the horizontal and vertical sides of the octagonal members thicker and the inclined plates thinner. Through the latter, we could more easily drill holes for manual access without losing stiffness in the design.” oct_constr

There is a reason why Sharma prefers to keep a strict mathematical control over design pre-processing. Maintaining a uniform accuracy to the infrastructure and design modifications carry on into post-processing, where the 3D data will feed into automatic CNC machining in the Malaysian fabrication shop.

The creation of the center line, the parsing of the center line, the panels, the understructure definition, the access holes – everything is programmed and generated automatically.  Every time something changes as part of the design evolution, we need to handle it consistently.  You also want to make sure you have a digital fabrication output without any manual intervention.  There are hardly any drawings of the skin panels, most all of the fabrication uses the 3D data directly to the factory machines.”

The Sitra Tree is an example of how architecture is borrowing from industrial design to take advantage of the efficiencies inherent in 3D technology.  The SMART group’s handling of the engineering ensures a high level of consistency throughout the thousands of pieces that make up the Sitra structure.  Each part is numbered and organized according to a machining and assembly schedule.  Because of the accuracy of the 3D processing and the CNC cuts, the tree is assembled with a perfect fit.

orSMART’s overall technique — using Rhinoceros as a central 3D hub which can transfer data back and forth to stand-alone tools such as ANSYS and Robot, further analyze and optimize designs through plug-ins and propriety software like SMARTForm, and schedule machining output through CNC devices  — is what Sharma calls “integrated modeling.”

“With integrated modeling,” Sharma says, “we can keep design, analysis, and fabrication essentially in one system that is truly automated.”

Learn more about SMART plug-ins for Rhino at:  www.burohappold.com/bh/srv_bld_smart_solutions.aspx.

About Buro Happold

Designers of elegant, bold, and sustainable engineering solutions for today’s built environment, Buro Happold builds for people.  With comprehensive services for any sized construction project, Buro Happold solves architectural, infrastructural, and environmental problems all over the globe.  For more information and to view past projects of Buro Happold, please visit: www.burohappold.com.


About Rhinoceros

Rhinoceros provides the tools to accurately model your designs ready for rendering, animation, drafting, engineering, analysis, and manufacturing.  Rhino can create, edit, analyze, and translate NURBS curves, surfaces, and solids in Windows, without limits on complexity, degree, or size.  Rhino gives the accuracy needed to design, prototype, engineer, analyze, and manufacture anything from an airplane to jewelry. To see the many diverse products designed with this affordable 3D tool, and to download a free evaluation version, please visit: www.rhino3D.com.