Pictures worth a thousand tiles, a geometrical programming language for self-assembly

International audienceWe present a novel way to design self-assembling systems using a notion of signal (or ray) akin to what is used in analyzing the behavior of cellular automata. This allows purely geometrical constructions, with a smaller specification and easier analysis. We show how to design a system of signals for a given set of shapes, and how to transform these signals into a set of tiles which self-assemble into the desired shapes. We show how to use this technique on three examples : squares (with optimal assembly time and a small number of tiles), general polygons, and a quasi periodic pattern : Robinson tiling

ALCH: An Imperative Language for Chemical Reaction Network-Controlled Tile Assembly

In 2015 Schiefer and Winfree introduced the chemical reaction network-controlled tile assembly model (CRN-TAM), a variant of the abstract tile assembly model (aTAM), where tile reactions are mediated via non-local chemical signals. In this paper, we introduce ALCH, an imperative programming language for specifying CRN-TAM programs. ALCH contains common features like Boolean variables, conditionals, and loops. It also supports CRN-TAM-specific features such as adding and removing tiles. A unique feature of the language is the branch statement, a nondeterministic control structure that allows us to query the current state of tile assemblies. We also developed a compiler that translates ALCH to the CRN-TAM, and a simulator that simulates and visualizes the self-assembly of a CRN-TAM program. Using this language, we show that the discrete Sierpinski triangle can be strictly self-assembled in the CRN-TAM. This solves an open problem that the CRN-TAM is capable of self-assembling infinite shapes at scale one that the aTAM cannot. ALCH allows us to present this construction at a high level, abstracting species and reactions into C-like code that is simpler to understand. Our construction utilizes two new CRN-TAM techniques that allow us to tackle this open problem. First, it employs the branching feature of ALCH to probe the previously placed tiles of the assembly and detect the presence and absence of tiles. Second, it uses scaffolding tiles to precisely control tile placement by occluding any undesired binding sites

Geometry linking the art of building and the Universe: Geometric patterns on shells and grid shells

Geometry links the art of building and the physics of space-time. Mathematical breakthroughs in geometry have led to new ways of designing our structures and our ability to visualise and describe the world, phenomena in nature and the universe. However, in contemporary architecture and structural engineering, a more profound understanding of geometry has been forgotten. This thesis aims to resurrect geometry in architecture and engineering in connection with the rapid development of new digital tools for design and production—particularly the connection between the structural action related to the design of the geometrical patterns on shells structures are treated. A brief historical overview of geometry is conducted, and with an emphasis on its applications in architecture in terms of structural design and economic production. Furthermore, the connection to a sustainable building culture from the standpoint of the Davos declaration 2018, calling for a high-quality Baukultur is investigated. The concept of Baukultur (building culture in English) defined in the Davos declaration is related to architectural quality but has a broader meaning as it concerns the final product and the associated processes and its effect in society. Moreover, the concept of craftsmanship and workshop culture is examined, and how it is already present in computer code development and contemporary innovative research cultures combining architectural design and technology. Taking departure from the 18th-century experimental scientist Joseph Plateau and the contemporary artist Andy Goldsworthy, the connection between scientific and artistic research is investigated.Four articles are included; all connected to various ways of architectural applications of geometry in the design process. The first article describes a way to interpret empirically derived brick patterns, specifically the bed joints, using differential geometry. Two methods to apply this in the design processes of new brick vaults are presented. The first is purely geometrical and can be applied on an arbitrary shape with the possibility to apply several patterns; the second is an iterative method of generating a funicular shape and its pattern simultaneously. The second and third paper describes the design and construction process of two different wooden structures built of straight planar laths. Both studies examine the possibilities of using geometry as a link between various parameters in a design process using digital tools to achieve complex forms using simple elements and production methods. The fourth paper examines an appropriate form for a shell, that can balance aesthetics, structural performance and build-ability, with a proposal for the use of surfaces with constant solid angle. In this paper, the surface was generated with a Delaunay triangulation. Thus, future studies would include incorporation of other types of patterns facilitating buildability

Self-assembly: modelling, simulation, and planning

Samoskládání je proces, při kterém se kolekce neuspořádaných částic samovolně orientuje do uspořádaného vzoru nebo funkční struktury bez působení vnější síly, pouze za pomoci lokálních interakcí mezi samotnými částicemi. Tato teze se zaměřuje na teorii dlaždicových samoskládacích systémů a jejich syntézu. Nejdříve je představena oblast výzkumu věnující se dlaždičovým samoskládacím systémům, a poté jsou důkladně popsány základní typy dlaždicových skládacích systémů, kterými jsou abstract Tile Assembly Model (aTAM ), kinetic Tile Assembly Model (kTAM ), a 2-Handed Assembly Model (2HAM ). Poté jsou představeny novější modely a modely se specifickým použitím. Dále je zahrnut stručný popis původu teorie dlaždicového samoskládání společně s krátkým popisem nedávného výzkumu. Dále jsou představeny dva obecné otevřené problémy dlaždicového samoskládání s hlavním zaměřením na problém Pattern Self-Assembly Tile Set Synthesis (PATS), což je NP-těžká kombinatorická optimalizační úloha. Nakonec je ukázán algoritmus Partition Search with Heuristics (PS-H ), který se používá k řešení problému PATS. Následovně jsou demonstrovány dvě aplikace, které byly vyvinuty pro podporu výzkumu abstraktních dlaždicových skládacích modelů a syntézy množin dlaždic pro samoskládání zadaných vzorů. První aplikace je schopná simulovat aTAM a 2HAM systémy ve 2D prostoru. Druhá aplikace je řešič PATS problému, který využívá algoritmu PS-H. Pro obě aplikace jsou popsány hlavní vlastnosti a návrhová rozhodnutí, která řídila jejich vývoj. Nakonec jsou předloženy výsledky několika experimentů. Jedna skupina experimentů byla zaměřena na ověření výpočetní náročnosti vyvinutých algoritmů pro simulátor. Druhá sada experimentů zkoumala vliv jednotlivých vlastností vzorů na vlastnosti dlaždicových systémů, které byly získány syntézou ze vzorů pomocí vyvinutého řešiče PATS problému. Bylo prokázáno, že algoritmus simulující aTAM systém má lineární časovou výpočetní náročnost, zatímco algoritmus simulující 2HAM systém má exponenciální časovou výpočetní náročnost, která navíc silně závisí na simulovaném systému. Aplikace pro řešení syntézy množiny dlaždic ze vzorů je schopna najít relativně malé řešení i pro velké zadané vzory, a to v přiměřeném čase.Self-assembly is the process in which a collection of disordered units organise themselves into ordered patterns or functional structures without any external direction, solely using local interactions among the components. This thesis focuses on the theory of tile-based self-assembly systems and their synthesis. First, an introduction to the study field of tile-based self-assembly systems are given, followed by a thorough description of common types of tile assembly systems such as abstract Tile Assembly Model (aTAM ), kinetic Tile Assembly Model (kTAM ), and 2-Handed Assembly Model (2HAM ). After that, various recently developed models and models with specific applications are listed. A brief summary of the origins of the tile-based self-assembly is also included together with a short review of recent results. Two general open problems are presented with the main focus on the Pattern Self-Assembly Tile Set Synthesis (PATS) problem, which is NP-hard combinatorial optimisation problem. Partition Search with Heuristics (PS-H ) algorithm is presented as it is used for solving the PATS problem. Next, two applications which were developed to study the abstract tile assembly models and the synthesis of tile sets for pattern self-assembly are introduced. The first application is a simulator capable of simulating aTAM and 2HAM systems in 2D. The second application is a solver of the PATS problem based around the PS-H algorithm. Main features and design decisions are described for both applications. Finally, results from several experiments are presented. One set of experiments were focused on verification of computation complexity of algorithms developed for the simulator, and the other set of experiments studied the influences of the properties of the pattern on the tile assembly system synthesised by our implementation of PATS problem solver. It was shown that the algorithm for simulating aTAM systems have linear computation time complexity, whereas the algorithm simulating 2HAM systems have exponential computation time complexity, which strongly varies based on the simulated system. The synthesiser application is capable of finding a relatively small solution even for quite large input patterns in reasonable amounts of time

An aesthetics of touch: investigating the language of design relating to form

How well can designers communicate qualities of touch? This paper presents evidence that they have some capability to do so, much of which appears to have been learned, but at present make limited use of such language. Interviews with graduate designer-makers suggest that they are aware of and value the importance of touch and materiality in their work, but lack a vocabulary to fully relate to their detailed explanations of other aspects such as their intent or selection of materials. We believe that more attention should be paid to the verbal dialogue that happens in the design process, particularly as other researchers show that even making-based learning also has a strong verbal element to it. However, verbal language alone does not appear to be adequate for a comprehensive language of touch. Graduate designers-makers’ descriptive practices combined non-verbal manipulation within verbal accounts. We thus argue that haptic vocabularies do not simply describe material qualities, but rather are situated competences that physically demonstrate the presence of haptic qualities. Such competencies are more important than groups of verbal vocabularies in isolation. Design support for developing and extending haptic competences must take this wide range of considerations into account to comprehensively improve designers’ capabilities

Tangible interfaces for manipulating aggregates of digital information

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.Includes bibliographical references (p. 255-269).This thesis develops new approaches for people to physically represent and interact with aggregates of digital information. These support the concept of Tangible User Interfaces (TUIs), a genre of human-computer interaction that uses spatially reconfigurable physical objects as representations and controls for digital information. The thesis supports the manipulation of information aggregates through systems of physical tokens and constraints. In these interfaces, physical tokens act as containers and parameters for referencing digital information elements and aggregates. Physical constraints are then used to map structured compositions of tokens onto a variety of computational interpretations. This approach is supported through the design and implementation of several systems. The mediaBlocks system enables people to use physical blocks to "copy and paste" digital media between specialized devices and general-purpose computers, and to physically compose and edit this content (e.g., to build multimedia presentations). This system also contributes new tangible interface techniques for binding, aggregating, and disaggregating sequences of digital information into physical objects.(cont.) Tangible query interfaces allow people to physically express and manipulate database queries. This system demonstrates ways in which tangible interfaces can manipulate larger aggregates of information. One of these query approaches has been evaluated in a user study, which has compared favorably with a best-practice graphical interface alternative. These projects are used to support the claim that physically constrained tokens can provide an effective approach for interacting with aggregates of digital information.by Brygg Anders Ullmer.Ph.D

Enabling the Development and Implementation of Digital Twins : Proceedings of the 20th International Conference on Construction Applications of Virtual Reality

Welcome to the 20th International Conference on Construction Applications of Virtual Reality (CONVR 2020). This year we are meeting on-line due to the current Coronavirus pandemic. The overarching theme for CONVR2020 is "Enabling the development and implementation of Digital Twins". CONVR is one of the world-leading conferences in the areas of virtual reality, augmented reality and building information modelling. Each year, more than 100 participants from all around the globe meet to discuss and exchange the latest developments and applications of virtual technologies in the architectural, engineering, construction and operation industry (AECO). The conference is also known for having a unique blend of participants from both academia and industry. This year, with all the difficulties of replicating a real face to face meetings, we are carefully planning the conference to ensure that all participants have a perfect experience. We have a group of leading keynote speakers from industry and academia who are covering up to date hot topics and are enthusiastic and keen to share their knowledge with you. CONVR participants are very loyal to the conference and have attended most of the editions over the last eighteen editions. This year we are welcoming numerous first timers and we aim to help them make the most of the conference by introducing them to other participants

Interpreting parametric-biomimicry design from cad тo bim software: digital modelling based on a sketch of nandi flame

This research represents an application of two digital modelling softwares, first digital modelling software, chosen as representative of Computer-Aided Design – CAD modelling tool was Fusion 360. The representative of Building Information Modelling (BIM) as second digital modelling software was ArchiCAD. The aim of the research was to translate the same parametric-biomimicry design methodology used in CAD process modelling into BIM environment. African species Spathodea campanulata P. Beauv, whose common name in Kenya is Nandi flame, has been selected for the purpose of this digital modelling processes. As one of the most spectacular flowering plants, Nandi flame is indigenous to the tropical dry forests in Kenya. The decorative flower of this species was the basic model, more precisely the botanical sketches of the flower. This sketches were implemented into digital modelling softwares and used for parametric modelling. The results of this processes were represented as urban models or installations (landscape-architectural elements) in open space. This approach of digitally generating conceptual solutions from nature elements has capability to boost the formulation of new creative inventions in the different fields. The unique geometric patterns found in the flower of Spathodea campanulata P. Beauv served as a good example of how we may transform these ideas into actual design installations– using CAD or BIM software tools. This research has been carried out with the aim to find the position of BIM tools in parametric biomimicry design