ACM Reference Format
Deuss, M., Panozzo, D., Whiting, E., Liu, Y., Block, P., Sorkine-Hornung, O., Pauly, M. 2014. Assembling
Self-Supporting Structures. ACM Trans. Graph. 33, 6, Article 214 (November 2014), 10 pages.
DOI = 10.1145/2661229.2661266 http://doi.acm.org/10.1145/2661229.2661266.
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DOI: http://doi.acm.org/10.1145/2661229.2661266
Assembling Self-Supporting Structures
Mario Deuss
1
Daniele Panozzo
2
Emily Whiting
2,3
Yang Liu
4
Philippe Block
2
Olga Sorkine-Hornung
2
Mark Pauly
1
1
EPF Lausanne
2
ETH Zurich
3
Dartmouth College
4
Microsoft Research
Figure 1:
We propose a construction method for self-supporting structures that uses chains, instead of a dense formwork, to support the blocks
during the intermediate construction stages. Our algorithm finds a work-minimizing sequence that guides the construction of the structure,
indicating which chains are necessary to guarantee stability at each step. From left to right: a self-supporting structure, an intermediate
construction stage with dense formwork, an intermediate construction stage with our method and the assembled model.
Abstract
Self-supporting structures are prominent in historical and contem-
porary architecture due to advantageous structural properties and
efficient use of material. Computer graphics research has recently
contributed new design tools that allow creating and interactively
exploring self-supporting freeform designs. However, the physical
construction of such freeform structures remains challenging, even
on small scales. Current construction processes require extensive
formwork during assembly, which quickly leads to prohibitively
high construction costs for realizations on a building scale. This
greatly limits the practical impact of the existing freeform design
tools. We propose to replace the commonly used dense formwork
with a sparse set of temporary chains. Our method enables gradual
construction of the masonry model in stable sections and drastically
reduces the material requirements and construction costs. We an-
alyze the input using a variational method to find stable sections,
and devise a computationally tractable divide-and-conquer strategy
for the combinatorial problem of finding an optimal construction se-
quence. We validate our method on 3D printed models, demonstrate
an application to the restoration of historical models, and create
designs of recreational, collaborative self-supporting puzzles.
CR Categories:
I.3.5 [Computer Graphics]: Computational Ge-
ometry and Object Modeling—Curve, surface, solid, and object
representations;
Keywords:
masonry models, static equilibrium analysis, self-
supporting surfaces, optimization, sparsity, assembly order
Links:
DL PDF WEB
1 Introduction
The majority of man-made objects are composed of multiple inter-
locking parts, kept together by glue, bolts or other connections. The
division into components is often necessary to achieve a certain
purpose (computers, cars) or to make the fabrication of large models
feasible or cheaper (buildings, furniture, roads, railways, large 3D
printed models, etc.).
In this work, we focus on the construction of self-supporting struc-
tures that are composed of bricks or stone blocks without any mortar
to bind them together. Most of the world’s architectural heritage
consist of self-supporting masonry structures that require no support-
ing framework, since the entire structure is in a static equilibrium
configuration.
The design of modern, freeform self-supporting structures has re-
cently received a lot of interest in computer graphics [Vouga et al
.
2012; Liu et al
.
2013; de Goes et al
.
2013; Panozzo et al
.
2013], but
their physical construction has only been addressed for small-scale
models. The method proposed in [Panozzo et al
.
2013] relies on
dense formwork (Figure 1) to support all the blocks until the entire
construction is completed; after the last piece is put in place, the
structure is in equilibrium and the formwork can be carefully re-
moved. This method is difficult to apply to large scale structures,
because a dense formwork able to sustain the weight of large stone
blocks is too expensive and not practical, especially considering that
the formwork has to be dismantled after all the blocks are in place.
Also, removing the formwork demands technically complex and
expensive solutions: the formwork has to be lowered evenly to avoid
failures due to redistribution of forces. Due to the lack of an econom-
ically feasible construction strategy, freeform masonry structures are
currently rarely built, despite their advantageous structural proper-
ties and unique aesthetics. Additionally, the majority of the cost is
associated with the foundations necessary to support the formwork.
We propose a different approach, replacing the dense formwork
with a sparse set of chains that are connected to fixed anchor points.
While chains have been used for construction before, our method
specifically aims at finding a work-minimizing assembly sequence,
requiring as few chains to be rehung as possible. Our solution
leverages the internal force distribution of the partially assembled
structure and only provides the minimally required additional sup-
ports to keep the structure in static equilibrium at all stages of the
assembly. The use of chains has been pioneered in modern construc-
ACM Transactions on Graphics, Vol. 33, No. 6, Article 214, Publication Date: November 2014