"Building 3D Worlds-3D Geometric Graphics I" & "Geometric Building"

The excerpt from Yehuda’s book, Geometric Modeling, gives a clear description of the different types of geometric modeling and touches on geometric operators at the very end. While Anne Spalter’s chapter “Building 3D Worlds-3D Geometric Graphics I” provides a very thorough overview of components in most current 3D modeling programs.

Yehuda’s chapter begins with descriptions of the three types of computer models that have developed since the 1960’s; wire frame models, surface models and solid models. Most current programs are solid modelers with wire frame and surface viewing capabilities. I was not aware of the three approaches to solid modeling: spatial occupancy enumeration, constructive solid geometry and boundary representation. Spatial occupancy enumeration was the most interesting to me. It represents “solids as sets of contiguous discrete ‘chucks’ of matter in three-dimensional space.” (Yehuda, 143) With b-rep models, the volume of an object is usually left empty because definition of the object occurs at the boundary lines. The exact opposite is true with spatial occupancy enumeration. Its major downfall is the amount of computing resources needed to model objects. Therefore, this type of modeling is used mostly in medical imaging where relatively small objects are created. Spalter talks briefly about this type of modeling I believe, when she refers to voxels, and raster based 3D programs. (Spalter 218) In Interior Architecture, it seems natural to use b-rep modeling. As designers of space, Interior Architects are interested in volume as open space. We are very aware of inside versus outside and the implication that has on the space we’re working within. It would be counterintuitive to use a modeling method such as spatial occupancy enumeration that cannot clearly distinguish the interior of an object or volume. If this type of modeling could be more about subtraction, similar to modeling clay, then perhaps in the future it could be a useful tool for the design of interior spaces.

Spalter’s article does not discuss the three types of geometric modeling, but it does provide a detailed overview of most 3D programs, including methods of creating objects, methods for assembling objects and a discussion on composing objects in a 3D scene. Her descriptions of primitives, sweeps, Boolean operations, splines and patches were very familiar to me. These are elements for creating objects within a 3D modeling program. What was less familiar and very interesting was the topic of algorithmic form generation. Fractals, grammars and graftals are all ways of generating natural forms based on the repetition of similar forms at different scales. The discussion on genetic art is based directly on the computer’s ability to create these natural shapes, along with mutations of those shapes, with minimal input from the user. The user becomes the designer in a sense by choosing which form is most pleasing and the computer continues working from there. Spalter uses “Genetic Images” a show at the Centre Georges Pompidou to illustrate genetic art. Viewers influenced the generation of the piece, based on which images they most enjoyed. (Spalter 245) Karl Chu is a Professor of Architecture at Cambridge University whose focus of study is genetic architecture.
(http://www.arch.columbia.edu/index.php?pageData=28630) Chu’s work is purely theoretical, but he is certainly one architect pushing the boundaries of the computer and 3D modeling, and the philosophical effects of using such a medium for idea and form generation.

So does the future of architecture and design involve the inevitability of the computer as designer? Are future buildings meant to be so different from our modern day ones that they are unrecognizable as buildings? We stand at a precipice of design. As designers we know that the way we build has to change. Our structures have to become more organic, at least in their actions, if not their appearance. And the computer can be a very useful tool for organizing and perhaps designing complex structures that will baffle the minds of humans. But what good will complex organic structures that mimic natural forms be when our main building materials are steel, glass, concrete, brick and wood? I really believe that it’s our responsibility as designers and architects, to use the computer creatively. Certainly it can generate unimaginable forms and even make sure those forms will stand. But at some point we have to ask if these dramatic forms of the computer are really necessary. We have to use common sense about the usability and footprint of such structures. Maybe that becomes our future role, as editors of computation.