Fast Exact Booleans for Iterated CSG using Octree-Embedded BSPs

We present octree-embedded BSPs, a volumetric mesh data structure suited for performing a sequence of Boolean operations (iterated CSG) efficiently. At its core, our data structure leverages a plane-based geometry representation and integer arithmetics to guarantee unconditionally robust operations. These typically present considerable performance challenges which we overcome by using custom-tailored fixed-precision operations and an efficient algorithm for cutting a convex mesh against a plane. Consequently, BSP Booleans and mesh extraction are formulated in terms of mesh cutting. The octree is used as a global acceleration structure to keep modifications local and bound the BSP complexity. With our optimizations, we can perform up to 2.5 million mesh-plane cuts per second on a single core, which creates roughly 40-50 million output BSP nodes for CSG. We demonstrate our system in two iterated CSG settings: sweep volumes and a milling simulation

From 3D Models to 3D Prints: an Overview of the Processing Pipeline

Due to the wide diffusion of 3D printing technologies, geometric algorithms for Additive Manufacturing are being invented at an impressive speed. Each single step, in particular along the Process Planning pipeline, can now count on dozens of methods that prepare the 3D model for fabrication, while analysing and optimizing geometry and machine instructions for various objectives. This report provides a classification of this huge state of the art, and elicits the relation between each single algorithm and a list of desirable objectives during Process Planning. The objectives themselves are listed and discussed, along with possible needs for tradeoffs. Additive Manufacturing technologies are broadly categorized to explicitly relate classes of devices and supported features. Finally, this report offers an analysis of the state of the art while discussing open and challenging problems from both an academic and an industrial perspective.Comment: European Union (EU); Horizon 2020; H2020-FoF-2015; RIA - Research and Innovation action; Grant agreement N. 68044

A Survey of Surface Reconstruction from Point Clouds

International audienceThe area of surface reconstruction has seen substantial progress in the past two decades. The traditional problem addressed by surface reconstruction is to recover the digital representation of a physical shape that has been scanned, where the scanned data contains a wide variety of defects. While much of the earlier work has been focused on reconstructing a piece-wise smooth representation of the original shape, recent work has taken on more specialized priors to address significantly challenging data imperfections, where the reconstruction can take on different representations – not necessarily the explicit geometry. We survey the field of surface reconstruction, and provide a categorization with respect to priors, data imperfections, and reconstruction output. By considering a holistic view of surface reconstruction, we show a detailed characterization of the field, highlight similarities between diverse reconstruction techniques, and provide directions for future work in surface reconstruction

Fabricate

Bringing together pioneers in design and making within architecture, construction, engineering, manufacturing, materials technology and computation, Fabricate is a triennial international conference, now in its third year (ICD, University of Stuttgart, April 2017). Each year it produces a supporting publication, to date the only one of its kind specialising in Digital Fabrication. The 2017 edition features 32 illustrated articles on built projects and works in progress from academia and practice, including contributions from leading practices such as Foster + Partners, Zaha Hadid Architects, Arup, and Ron Arad, and from world-renowned institutions including ICD Stuttgart, Harvard, Yale, MIT, Princeton University, The Bartlett School of Architecture (UCL) and the Architectural Association

Exploring the potential of physical visualizations

The goal of an external representation of abstract data is to provide insights and convey information about the structure of the underlying data, therefore helping people execute tasks and solve problems more effectively. Apart from the popular and well-studied digital visualization of abstract data there are other scarcely studied perceptual channels to represent data such as taste, sound or haptic. My thesis focuses on the latter and explores in which ways human knowledge and ability to sense and interact with the physical non-digital world can be used to enhance the way in which people analyze and explore abstract data. Emerging technological progress in digital fabrication allow an easy, fast and inexpensive production of physical objects. Machines such as laser cutters and 3D printers enable an accurate fabrication of physical visualizations with different form factors as well as materials. This creates, for the first time, the opportunity to study the potential of physical visualizations in a broad range. The thesis starts with the description of six prototypes of physical visualizations from static examples to digitally augmented variations to interactive artifacts. Based on these explorations, three promising areas of potential for physical visualizations were identified and investigated in more detail: perception & memorability, communication & collaboration, and motivation & self-reflection. The results of two studies in the area of information recall showed that participants who used a physical bar chart retained more information compared to the digital counterpart. Particularly facts about maximum and minimum values were be remembered more efficiently, when they were perceived from a physical visualization. Two explorative studies dealt with the potential of physical visualizations regarding communication and collaboration. The observations revealed the importance on the design and aesthetic of physical visualizations and indicated a great potential for their utilization by audiences with less interest in technology. The results also exposed the current limitations of physical visualizations, especially in contrast to their well-researched digital counterparts. In the area of motivation we present the design and evaluation of the Activity Sculptures project. We conducted a field study, in which we investigated physical visualizations of personal running activity. It was discovered that these sculptures generated curiosity and experimentation regarding the personal running behavior as well as evoked social dynamics such as discussions and competition. Based on the findings of the aforementioned studies this thesis concludes with two theoretical contributions on the design and potential of physical visualizations. On the one hand, it proposes a conceptual framework for material representations of personal data by describing a production and consumption lens. The goal is to encourage artists and designers working in the field of personal informatics to harness the interactive capabilities afforded by digital fabrication and the potential of material representations. On the other hand we give a first classification and performance rating of physical variables including 14 dimensions grouped into four categories. This complements the undertaking of providing researchers and designers with guidance and inspiration to uncover alternative strategies for representing data physically and building effective physical visualizations.Um aus abstrakten Daten konkrete Aussagen, komplexe Zusammenhänge oder überraschende Einsichten gewinnen zu können, müssen diese oftmals in eine, für den Menschen, anschauliche Form gebracht werden. Eine weitverbreitete und gut erforschte Möglichkeiten ist die Darstellung von Daten in visueller Form. Weniger erforschte Varianten sind das Verkörpern von Daten durch Geräusche, Gerüche oder physisch ertastbare Objekte und Formen. Diese Arbeit konzentriert sich auf die letztgenannte Variante und untersucht wie die menschlichen Fähigkeiten mit der physischenWelt zu interagieren dafür genutzt werden können, das Analysieren und Explorieren von Daten zu unterstützen. Der technische Fortschritt in der digitalen Fertigung vereinfacht und beschleunigt die Produktion von physischen Objekten und reduziert dabei deren Kosten. Lasercutter und 3D Drucker ermöglichen beispielsweise eine maßgerechte Fertigung physischer Visualisierungen verschiedenster Ausprägungen hinsichtlich Größe und Material. Dadurch ergibt sich zum ersten Mal die Gelegenheit, das Potenzial von physischen Visualisierungen in größerem Umfang zu erforschen. Der erste Teil der Arbeit skizziert insgesamt sechs Prototypen physischer Visualisierungen, wobei sowohl statische Beispiele beschrieben werden, als auch Exemplare die durch digital Inhalte erweitert werden oder dynamisch auf Interaktionen reagieren können. Basierend auf den Untersuchungen dieser Prototypen wurden drei vielversprechende Bereiche für das Potenzial physischer Visualisierungen ermittelt und genauer untersucht: Wahrnehmung & Einprägsamkeit, Kommunikation & Zusammenarbeit sowie Motivation & Selbstreflexion. Die Ergebnisse zweier Studien zur Wahrnehmung und Einprägsamkeit von Informationen zeigten, dass sich Teilnehmer mit einem physischen Balkendiagramm an deutlich mehr Informationen erinnern konnten, als Teilnehmer, die eine digitale Visualisierung nutzten. Insbesondere Fakten über Maximal- und Minimalwerte konnten besser im Gedächtnis behalten werden, wenn diese mit Hilfe einer physischen Visualisierung wahrgenommen wurden. Zwei explorative Studien untersuchten das Potenzial von physischen Visualisierungen im Bereich der Kommunikation mit Informationen sowie der Zusammenarbeit. Die Ergebnisse legten einerseits offen wie wichtig ein ausgereiftes Design und die Ästhetik von physischen Visualisierungen ist, deuteten anderseits aber auch darauf hin, dass Menschen mit geringem Interesse an neuen Technologien eine interessante Zielgruppe darstellen. Die Studien offenbarten allerdings auch die derzeitigen Grenzen von physischen Visualisierungen, insbesondere im Vergleich zu ihren gut erforschten digitalen Pendants. Im Bereich der Motivation und Selbstreflexion präsentieren wir die Entwicklung und Auswertung des Projekts Activity Sculptures. In einer Feldstudie über drei Wochen erforschten wir physische Visualisierungen, die persönliche Laufdaten repräsentieren. Unsere Beobachtungen und die Aussagen der Teilnehmer ließen darauf schließen, dass die Skulpturen Neugierde weckten und zum Experimentieren mit dem eigenen Laufverhalten einluden. Zudem konnten soziale Dynamiken entdeckt werden, die beispielsweise durch Diskussion aber auch Wettbewerbsgedanken zum Ausdruck kamen. Basierend auf den gewonnen Erkenntnissen durch die erwähnten Studien schließt diese Arbeit mit zwei theoretischen Beiträgen, hinsichtlich des Designs und des Potenzials von physischen Visualisierungen, ab. Zuerst wird ein konzeptionelles Framework vorgestellt, welches die Möglichkeiten und den Nutzen physischer Visualisierungen von persönlichen Daten veranschaulicht. Für Designer und Künstler kann dies zudem als Inspirationsquelle dienen, wie das Potenzial neuer Technologien, wie der digitalen Fabrikation, zur Darstellung persönlicher Daten in physischer Form genutzt werden kann. Des Weiteren wird eine initiale Klassifizierung von physischen Variablen vorgeschlagen mit insgesamt 14 Dimensionen, welche in vier Kategorien gruppiert sind. Damit vervollständigen wir unser Ziel, Forschern und Designern Inspiration und Orientierung zu bieten, um neuartige und effektvolle physische Visualisierungen zu erschaffen

HyperCell: A Bio-inspired Design Framework for Real-time Interactive Architectures

This pioneering research focuses on Biomimetic Interactive Architecture using “Computation”, “Embodiment”, and “Biology” to generate an intimate embodied convergence to propose a novel rule-based design framework for creating organic architectures composed of swarm-based intelligent components. Furthermore, the research boldly claims that Interactive Architecture should emerge as the next truly Organic Architecture. As the world and society are dynamically changing, especially in this digital era, the research dares to challenge the Utilitas, Firmitas, and Venustas of the traditional architectural Weltanschauung, and rejects them by adopting the novel notion that architecture should be dynamic, fluid, and interactive. This project reflects a trajectory from the 1960’s with the advent of the avant-garde architectural design group, Archigram, and its numerous intriguing and pioneering visionary projects. Archigram’s non-standard, mobile, and interactive projects profoundly influenced a new generation of architects to explore the connection between technology and their architectural projects. This research continues this trend of exploring novel design thinking and the framework of Interactive Architecture by discovering the interrelationship amongst three major topics: “Computation”, “Embodiment”, and “Biology”. The project aims to elucidate pioneering research combining these three topics in one discourse: “Bio-inspired digital architectural design”. These three major topics will be introduced in this Summary.   “Computation”, is any type of calculation that includes both arithmetical and nonarithmetical steps and follows a well-defined model understood and described as, for example, an algorithm. But, in this research, refers to the use of data storage, parametric design application, and physical computing for developing informed architectural designs. “Form” has always been the most critical focus in architectural design, and this focus has also been a major driver behind the application computational design in Architecture. Nonetheless, this research will interpret the term “Form” in architecture as a continual “information processor” rather than the result of information processing. In other words, “Form” should not be perceived only as an expressive appearance based computational outcome but rather as a real-time process of information processing, akin to organic “Formation”. Architecture embodying kinetic ability for adjusting or changing its shape with the ability to process the surroundings and feedback in accordance with its free will with an inherent interactive intelligent movement of a living body. Additionally, it is also crucial to address the question of whether computational technologies are being properly harnessed, if they are only used for form-generating purposes in architecture design, or should this be replaced with real-time information communication and control systems to produce interactive architectures, with embodied computation abilities?   “Embodiment” in the context of this research is embedded in Umberto Eco’s vision on Semiotics, theories underlying media studies in Marshall McLuhan’s “Body Extension” (McLuhan, 1964), the contemporary philosophical thought of “Body Without Organs” (Gilles Deleuze and Félix Guattari, 1983), the computational Logic of ‘Swarm Behavior’ and the philosophical notion of “Monadology” proposed by Gottfried Leibniz (Leibniz, 1714). Embodied computation and design are predominant today within the wearable computing and smart living domains, which combine Virtual and Real worlds. Technical progress and prowess in VR development also contribute to advancing 3D smart architectural design and display solutions. The proposed ‘Organic body-like architectural spaces’ emphasize upon the realization of a body-like interactive space. Developing Interactive Architecture will imply eliciting the collective intelligence prevalent in nature and the virtual world of Big Data. Interactive Architecture shall thus embody integrated Information exchange protocols and decision-making systems in order to possess organic body-like qualities.   “Biology”, in this research explores biomimetic principles intended to create purposedriven kinetic and organic architecture. This involves a detailed study/critique of organic architecture, generating organic shapes, performance optimization based digital fabrication techniques and kinetic systems. A holistic bio-inspired architecture embodies multiple performance criteria akin to natural systems, which integrate structural, infrastructure performances throughout the growth of an organic body. Such a natural morphogenesis process of architectural design explores what Janine M. Benyus described as “learning the natural process”. Profoundly influenced by the processes behind morphogenesis, the research further explores Evolutionary Development Biology (Evo-Devo) explaining how embryological regulation strongly affect the resulting formations. Evo-Devo in interactive architecture implies the development of architecture based on three fundamental principles: “Simple to Complex”, “Geometric Information Distribution”, and “On/Off Switch and Trigger.” The research seeks to create a relatively intelligent architectural body, and the tactile interactive spatial environment by applying the extracted knowledge from the study of the aforementioned principles of Evo-Devo in the following fashion: A. Extract a Self-Similar Componential System based approach from the “Simple to Complex” principle of Evo-Devo B. Extract the idea of “Collective Intelligence” from “Geometric information Distribution” principle of Evo-Devo C. Extract the principle of “Assembly Regulation” from “On/Off switch and trigger” principle of Evo-Devo The “HyperCell” research, through an elaborate investigation on the three aforementioned topics, develops a design framework for developing real-time adaptive spatial systems. HyperCell does this, by developing a system of transformable cubic elements which can self-organize, adapt and interact in real-time. These Hypercells shall comprise an organic space which can adjust itself in relation to our human bodies. The furniture system is literally reified and embodied to develop an intra-active space that proactively provokes human movement. The space thus acquires an emotive dimension and can become your pet, partner, or even friend, and might also involve multiple usabilities of the same space. The research and its progression were also had actively connected with a 5-year collaborative European Culture project: “MetaBody”. The research thus involves exploration of Interactive Architecture from the following perspectives: architectural design, digital architectural history trajectory, computational technology, philosophical discourse related to the embodiment, media and digital culture, current VR and body-related technology, and Evolutionary Developmental Biology. “HyperCell” will encourage young architects to pursue interdisciplinary design initiatives via the fusion of computational design, embodiment, and biology for developing bio-inspired organic architectures

HyperCell: A Bio-inspired Design Framework for Real-time Interactive Architectures

This pioneering research focuses on Biomimetic Interactive Architecture using “Computationâ€, “Embodimentâ€, and “Biology†to generate an intimate embodied convergence to propose a novel rule-based design framework for creating organic architectures composed of swarm-based intelligent components. Furthermore, the research boldly claims that Interactive Architecture should emerge as the next truly Organic Architecture. As the world and society are dynamically changing, especially in this digital era, the research dares to challenge the Utilitas, Firmitas, and Venustas of the traditional architectural Weltanschauung, and rejects them by adopting the novel notion that architecture should be dynamic, fluid, and interactive. This project reflects a trajectory from the 1960’s with the advent of the avant-garde architectural design group, Archigram, and its numerous intriguing and pioneering visionary projects. Archigram’s non-standard, mobile, and interactive projects profoundly influenced a new generation of architects to explore the connection between technology and their architectural projects. This research continues this trend of exploring novel design thinking and the framework of Interactive Architecture by discovering the interrelationship amongst three major topics: “Computationâ€, “Embodimentâ€, and “Biologyâ€. The project aims to elucidate pioneering research combining these three topics in one discourse: “Bio-inspired digital architectural designâ€. These three major topics will be introduced in this Summary. “Computationâ€, is any type of calculation that includes both arithmetical and nonarithmetical steps and follows a well-defined model understood and described as, for example, an algorithm. But, in this research, refers to the use of data storage, parametric design application, and physical computing for developing informed architectural designs. “Form†has always been the most critical focus in architectural design, and this focus has also been a major driver behind the application computational design in Architecture. Nonetheless, this research will interpret the term “Form†in architecture as a continual “information processor†rather than the result of information processing. In other words, “Form†should not be perceived only as an expressive appearance based computational outcome but rather as a real-time process of information processing, akin to organic “Formationâ€. Architecture embodying kinetic ability for adjusting or changing its shape with the ability to process the surroundings and feedback in accordance with its free will with an inherent interactive intelligent movement of a living body. Additionally, it is also crucial to address the question of whether computational technologies are being properly harnessed, if they are only used for form-generating purposes in architecture design, or should this be replaced with real-time information communication and control systems to produce interactive architectures, with embodied computation abilities? “Embodiment†in the context of this research is embedded in Umberto Eco’s vision on Semiotics, theories underlying media studies in Marshall McLuhan’s “Body Extension†(McLuhan, 1964), the contemporary philosophical thought of “Body Without Organs†(Gilles Deleuze and Félix Guattari, 1983), the computational Logic of ‘Swarm Behavior’ and the philosophical notion of “Monadology†proposed by Gottfried Leibniz (Leibniz, 1714). Embodied computation and design are predominant today within the wearable computing and smart living domains, which combine Virtual and Real worlds. Technical progress and prowess in VR development also contribute to advancing 3D smart architectural design and display solutions. The proposed ‘Organic body-like architectural spaces’ emphasize upon the realization of a body-like interactive space. Developing Interactive Architecture will imply eliciting the collective intelligence prevalent in nature and the virtual world of Big Data. Interactive Architecture shall thus embody integrated Information exchange protocols and decision-making systems in order to possess organic body-like qualities. “Biologyâ€, in this research explores biomimetic principles intended to create purposedriven kinetic and organic architecture. This involves a detailed study/critique of organic architecture, generating organic shapes, performance optimization based digital fabrication techniques and kinetic systems. A holistic bio-inspired architecture embodies multiple performance criteria akin to natural systems, which integrate structural, infrastructure performances throughout the growth of an organic body. Such a natural morphogenesis process of architectural design explores what Janine M. Benyus described as “learning the natural processâ€. Profoundly influenced by the processes behind morphogenesis, the research further explores Evolutionary Development Biology (Evo-Devo) explaining how embryological regulation strongly affect the resulting formations. Evo-Devo in interactive architecture implies the development of architecture based on three fundamental principles: “Simple to Complexâ€, “Geometric Information Distributionâ€, and “On/Off Switch and Trigger.†The research seeks to create a relatively intelligent architectural body, and the tactile interactive spatial environment by applying the extracted knowledge from the study of the aforementioned principles of Evo-Devo in the following fashion: A. Extract a Self-Similar Componential Systembased approach from the “Simple to Complex†principle of Evo-Devo B. Extract the idea of “Collective Intelligence†from “Geometric information Distribution†principle of Evo-Devo C. Extract the principle of “Assembly Regulation†from “On/Off switch and trigger†principle of Evo-Devo The “HyperCell†research, through an elaborate investigation on the three aforementioned topics, develops a design framework for developing real-time adaptive spatial systems. HyperCell does this, by developing a system of transformable cubic elements which can self-organize, adapt and interact in real-time. These Hypercells shall comprise an organic space which can adjust itself in relation to our human bodies. The furniture system is literally reified and embodied to develop an intra-active space that proactively provokes human movement. The space thus acquires an emotive dimension and can become your pet, partner, or even friend, and might also involve multiple usabilities of the same space. The research and its progression were also had actively connected with a 5-year collaborative European Culture project: “MetaBodyâ€. The research thus involves exploration of Interactive Architecture from the following perspectives: architectural design, digital architectural history trajectory, computational technology, philosophical discourse related to the embodiment, media and digital culture, current VR and body-related technology, and Evolutionary Developmental Biology. “HyperCell†will encourage young architects to pursue interdisciplinary design initiatives via the fusion of computational design, embodiment, and biology for developing bio-inspired organic architectures

GPU data structures for graphics and vision

Graphics hardware has in recent years become increasingly programmable, and its programming APIs use the stream processor model to expose massive parallelization to the programmer. Unfortunately, the inherent restrictions of the stream processor model, used by the GPU in order to maintain high performance, often pose a problem in porting CPU algorithms for both video and volume processing to graphics hardware. Serial data dependencies which accelerate CPU processing are counterproductive for the data-parallel GPU. This thesis demonstrates new ways for tackling well-known problems of large scale video/volume analysis. In some instances, we enable processing on the restricted hardware model by re-introducing algorithms from early computer graphics research. On other occasions, we use newly discovered, hierarchical data structures to circumvent the random-access read/fixed write restriction that had previously kept sophisticated analysis algorithms from running solely on graphics hardware. For 3D processing, we apply known game graphics concepts such as mip-maps, projective texturing, and dependent texture lookups to show how video/volume processing can benefit algorithmically from being implemented in a graphics API. The novel GPU data structures provide drastically increased processing speed, and lift processing heavy operations to real-time performance levels, paving the way for new and interactive vision/graphics applications.Graphikhardware wurde in den letzen Jahren immer weiter programmierbar. Ihre APIs verwenden das Streamprozessor-Modell, um die massive Parallelisierung auch für den Programmierer verfügbar zu machen. Leider folgen aus dem strikten Streamprozessor-Modell, welches die GPU für ihre hohe Rechenleistung benötigt, auch Hindernisse in der Portierung von CPU-Algorithmen zur Video- und Volumenverarbeitung auf die GPU. Serielle Datenabhängigkeiten beschleunigen zwar CPU-Verarbeitung, sind aber für die daten-parallele GPU kontraproduktiv . Diese Arbeit präsentiert neue Herangehensweisen für bekannte Probleme der Video- und Volumensverarbeitung. Teilweise wird die Verarbeitung mit Hilfe von modifizierten Algorithmen aus der frühen Computergraphik-Forschung an das beschränkte Hardwaremodell angepasst. Anderswo helfen neu entdeckte, hierarchische Datenstrukturen beim Umgang mit den Schreibzugriff-Restriktionen die lange die Portierung von komplexeren Bildanalyseverfahren verhindert hatten. In der 3D-Verarbeitung nutzen wir bekannte Konzepte aus der Computerspielegraphik wie Mipmaps, projektive Texturierung, oder verkettete Texturzugriffe, und zeigen auf welche Vorteile die Video- und Volumenverarbeitung aus hardwarebeschleunigter Graphik-API-Implementation ziehen kann. Die präsentierten GPU-Datenstrukturen bieten drastisch schnellere Verarbeitung und heben rechenintensive Operationen auf Echtzeit-Niveau. Damit werden neue, interaktive Bildverarbeitungs- und Graphik-Anwendungen möglich

Fabricate 2017

Bringing together pioneers in design and making within architecture, construction, engineering, manufacturing, materials technology and computation, Fabricate is a triennial international conference, now in its third year (ICD, University of Stuttgart, April 2017). Each year it produces a supporting publication, to date the only one of its kind specialising in Digital Fabrication. The 2017 edition features 32 illustrated articles on built projects and works in progress from academia and practice, including contributions from leading practices such as Foster + Partners, Zaha Hadid Architects, Arup, and Ron Arad, and from world-renowned institutions including ICD Stuttgart, Harvard, Yale, MIT, Princeton University, The Bartlett School of Architecture (UCL) and the Architectural Association