Three-dimensional reconstruction of plant shoots from multiple images using an active vision system

The reconstruction of 3D models of plant shoots is a challenging problem central to the emerging discipline of plant phenomics – the quantitative measurement of plant structure and function. Current approaches are, however, often limited by the use of static cameras. We propose an automated active phenotyping cell to reconstruct plant shoots from multiple images using a turntable capable of rotating 360 degrees and camera mounted robot arm. To overcome the problem of static camera positions we develop an algorithm capable of analysing the environment and determining viewpoints from which to capture initial images suitable for use by a structure from motion technique

On expert performance in 3D curve-drawing tasks

A study is described which examines the drawing accuracy of experts when drawing foreshortened projections of 3D curves in ecologically-valid conditions. The main result of this study is that the distribution of error in expert drawings exhibits a bias similar to that previously observed in non-expert subjects, which is dependent on the degree of foreshortening of the imagined drawing surface. A review of existing perceptual studies also finds that only absolute 2D image-space error has been considered, which has been found to be largest with viewing angles of 25-55 ◦. Our visualizations of 3D error indicate that 3D bias continues to increase with decreasing viewing angle. Based on these findings, we analyze current 3D curve drawing techniques for susceptibility to foreshortening bias, and make suggestions for future sketch-based modeling systems

Interação Entre o Arquiteto e as Ferramentas Digitais nas Etapas Iniciais de Projeto

In the early stages of design, the architect works by applying implicit knowledge to make initially diffuse and progressively better-defined decisions. This progression needs a kind of representation that could adapt to this reflective process, such as the sketch. Among the many digital technologies available, architects do not count with one that supports the early stages of design in this way. This absence leads to workflow issues and fails to address performance solutions. A comparative study is presented, in which experimental software functionalities existing between 2003 and 2014 were tested using available hardware, to support these activities. Furthermore, it described how these functionalities should be integrated to meet the needs in architectural drawing and design in the early stages. Key-words: Human-Computer Interaction, Architectural Design, Digital Modeling, Performance Simulation.Nas etapas iniciais de projeto, o arquiteto trabalha aplicando conhecimento implícito para tomar decisões inicialmente difusas e progressivamente melhor definidas. Esta progressão precisa de representações que se adaptem a este processo reflexivo, como o croquis. Dentre as muitas tecnologias digitais disponíveis, os arquitetos não contam com uma que apoie desta maneira as etapas iniciais, trazendo problemas de fluxo de trabalho e deixando de abordar soluções de desempenho. Apresenta-se um estudo comparativo das funcionalidades de software experimentais dentre 2003 e 2014 que, utilizando hardware disponível, apoiam estas atividades; e descreve-se como estas funcionalidades devem ser integradas para atender às necessidades de desenho e projeto arquitetônico nas etapas iniciais. Palavras-chave: Interação Humano-Computador; Projeto Arquitetônico; Modelagem Digital; Simulação de Desempenho

Integration of sketch-based ideation and 3D modeling with CAD systems

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis is concerned with the study of how sketch-based systems can be improved to enhance idea generation process in conceptual design stage. It is also concerned with achieving a kind of integration between sketch-based systems and CAD systems to complete the digitization of the design process as sketching phase is still not integrated with other phases due to the different nature of it and the incomplete digitization of sketching phase itself. Previous studies identified three main related issues: sketching process, sketch-based modeling, and the integration between the digitized design phases. Here, the thesis is motivated from the desire to improve sketch-based modeling to support idea generation process but unlike previous studies that only focused on the technical or drawing part of sketching, this thesis attempts to concentrate more on the mental part of the sketching process which play a key role in developing ideas in design. Another motivation of this thesis is to produce a kind of integration between sketch-based systems and CAD systems to enable 3D models produced by sketching to be edited in detailed design stage. As such, there are two main contributions have been addressed in this thesis. The first contribution is the presenting of a new approach in designing sketch-based systems that enable more support for idea generation by separating thinking and developing ideas from the 3D modeling process. This kind of separation allows designers to think freely and concentrate more on their ideas rather than 3D modeling. the second contribution is achieving a kind of integration between gesture-based systems and CAD systems by using an IGES file in exchanging data between systems and a new method to organize data within the file in an order that make it more understood by feature recognition embedded in commercial CAD systems.This study is funded by the Ministry of Higher Education of Egypt

Diagnostic study on shape perception errors within 3D-modeling courses

Form has always been a central concern for design -- Several tools and strategies have been developed aiming to support form generation from different perspectives -- And these issues are also a matter of study for design education -- Under this view, it is relevant to explore how technology and new interactions can aid design students to better understand form generation -- The present study, therefore, is centered on the 3D-modeling courses (ID0245-Modelación 3D1 and ID0267- Modelación 3D2) and tools (PTC® Creo 3.0™) provided inside the Product Design Engineering syllabus at EAFIT University -- In the ever changing academic world, new generations of students will be always in need of new methodological approaches from educators, in order to better understand the knowledge they are being given -- Curriculum adaptations will be always necessary to achieve this goal -- Therefore, the scope of the present study aims to set the ground for new teaching strategies around the 3D-modeling courses, based on the most commonly identified errors and difficulties found in 3D-modeling students -- These errors or difficulties might not be isolated factors, only present in the named courses -- They can be intrinsically connected with the acquired skills from other form generation-related courses, such as Drawing and Projects (where physical model are built and techniques are introduced by guidance) -- However, since the project is framed by the mentioned 3D-modeling tools and courses, it is necessary to understand how form is being generated inside 3D digital environments as a starting point for future work -- Nowadays, individual software provide increasing capabilities to help achieving specific modeling tasks -- This segmentation and specialization demands high expertize from users to become accustomed and keep up with the ever demanding industry standards -- Nonetheless, speed and quality cannot be compromised -- Hence, the main target around the study will be design students that take their first steps towards product embodiment -- The project, therefore, aims to understand how students approach styling activities and to report on their most common mistakes -- It is based on how they perceive 2D representations of products and how accurate their 3D-models are, based on selected shape properties -- This will serve as an essential input for new teaching strategies towards students’ self-awareness when performing in 3D form-giving environment

Toward semantic model generation from sketch and multi-touch interactions

Designers usually start their design process by exploring and evolving their ideas rapidly through sketching since this helps them to make numerous attempts at creating, practicing, simulating, and representing ideas. Creativity inherent in solving the ill-defined problems (Eastman, 1969) often emerges when designers explore potential solutions while sketching in the design process (Schön, 1992). When using computer programs such as CAD or Building Information Modeling (BIM) tools, designers often preplan the tasks prior to executing commands instead of engaging in the process of designing. Researchers argue that these programs force designers to focus on how to use a tool (i.e. how to execute series of commands) rather than how to explore a design, and thus hinder creativity in the early stages of the design process (Goel, 1995; Dorta, 2007). Since recent design and documentation works have been computer-generated using BIM software, transitions between ideas in sketches and those in digital CAD systems have become necessary. By employing sketch interactions, we argue that a computer system can provide a rapid, flexible, and iterative method to create 3D models with sufficient data for facilitating smooth transitions between designers’ early sketches and BIM programs. This dissertation begins by describing the modern design workflows and discussing the necessary data to be exchanged in the early stage of design. It then briefly introduces the modern cognitive theories, including embodiment (Varela, Rosch, & Thompson, 1992), situated action (Suchman, 1986), and distributed cognition (Hutchins, 1995). It continues by identifying problems in current CAD programs used in the early stage of the design process, using these theories as lenses. After reviewing modern attempts, including sketch tools and design automation tools, we describe the design and implementation of a sketch and multi-touch program, SolidSketch, to facilitate and augment our abilities to work on ill-defined problems in the early stage of design. SolidSketch is a parametric modeling program that enables users to construct 3D parametric models rapidly through sketch and multi-touch interactions. It combines the benefits of traditional design tools, such as physical models and pencil sketches (i.e. rapid, low-cost, and flexible methods), with the computational power offered by digital modeling tools, such as CAD. To close the gap between modern BIM and traditional sketch tools, the models created with SolidSketch can be read by other BIM programs. We then evaluate the programs with comparisons to the commercial CAD programs and other sketch programs. We also report a case study in which participants used the system for their design explorations. Finally, we conclude with the potential impacts of this new technology and the next steps for ultimately bringing greater computational power to the early stages of design.Ph.D

Facet-based Indexing of Multiple Artifacts - A Framework to Cope with Vague Search Requests in the Domain of Product Development

Durch den zunehmenden Einsatz von Informations- und Kommunikationstechnologien sowie den schnellen Technologiefortschritt steht die Entwicklung technischer Produkte vor immer neuen Herausforderungen. Dabei ist die Aufgabe der Produktentwicklung selbst als Problemlösungsprozess zu betrachten, in dem Lösungen mittels intensiver Informationsverarbeitung gefunden werden. Somit werden täglich unterschiedlichste Arten von Informationen erstellt, benötigt und verarbeitet, die primär in digitaler Form vorliegen. Diese werden in heterogenen Anwendungssystemen verwaltet, was eine Wiederverwendung bereits existierender Informationen erschwert. Damit beansprucht die Suche nach Informationen noch immer einen erheblichen Anteil der Entwicklungszeit. Zur Verbesserung der Informationsversorgung im Bereich der technischen Produktentwicklung wird ein interaktives Information Retrieval-System – das LFRP-Framework – vorgestellt. Dieses kombiniert die vier Basiskonzepte der multiplen Ebenen, der facettierten Suche, des Rankings und der parallelen Koordinaten, um hochkomplexe Informationsbedürfnisse zu befriedigen. Seine Realisierung erfordert neben einer geeigneten Suchoberfläche die Entwicklung einer Indexierungskomponente, welche die vorhandenen Informationen in eine für das LFRP-Framework rechnerverarbeitbare Form transformiert. Dieser als Indexierung bezeichnete Prozess stellt die Grundvoraussetzung für die Funktionsfähigkeit eines Suchsystems dar und liegt daher im Fokus der Betrachtung. Es wird ein Lösungsansatz vorgestellt, welcher eine Indexierung in Form facettenbasierter Suchkriterien ermöglicht und dabei nicht nur Informationen aus heterogenen Anwendungssystemen, sondern insbesondere aus entwicklungsspezifischen Dokumenten, wie CAD-Modellen, technischen Zeichnungen oder Stücklisten, berücksichtigt.Due to both the increasing use of information and communication technology as well as the fast technological progress the domain of product development has to face new challenges. Thereby, the task of developing products is a problem solving process itself and requires intensive information processing activities in order to find appropriate solutions. Thus, a variety of information is generated, needed and processed every day. Mostly available in digital form, this data is archived in heterogenous application systems. This makes it difficult to re-use already existing data. Consequently, a significant part of the development time is still affected by searching for information. In order to improve the supply of data and information in the domain of product development an interactive information retrieval system – the LFRP framework – is proposed. This framework combines four core concepts – multiple layers, facetted search, ranking, and parallel coordinates – to satisfy information needs of high complexity. Besides an appropriate search interface, realizing this framework necessitates an indexing component, too. This component is the prerequisite for operating a search system and therefore presents the main issue of this work. The proposed approach enables an indexing process by using facetted search criteria. For this purpose, data provided not only by heterogenous application systems but also by documents characteristic for the development of products such as CAD models, technical drawings, or bills of materials is considered

2nd Eurographics Workshop on Sketch-Based Interfaces and Modeling (2005) T. Igarashi (Chair) A Sketch-Based Interface for Iterative Design and Analysis of 3D Objects

This paper presents a freehand, sketch-based interface for Computed Aided Design (CAD) engineering design and finite element analysis. After a user sketches a two dimensional sketch consisting of connected straight and curved strokes, the sketch is processed by two optimization-based reconstruction algorithms that can reconstruct sketches of 3D objects made up of straight lines and planar curves. The proposed implementation allows certain types of objects with over 50 strokes to be reconstructed in interactive time. Following reconstruction, the structural properties of the 3D shape can be examined using finite element analysis. The object can quickly be modified using the pen-based interface according to the results of the analysis. The combination of a rapid, sketch-based design interface and finite element analysis allows users to iteratively design, analyze and modify 3D objects in an intuitive and flexible way. Categories and Subject Descriptors (according to ACM CCS): I.3.6 [Computer Graphics]: Interaction Techniques 1