Fabrication-aware Design with Intersecting Planar Pieces

We propose a computational design approach to generate 3D models composed of interlocking planar pieces. We show how intricate 3D forms can be created by sliding the pieces into each other along straight slits, leading to a simple construction that does not require glue, screws, or other means of support. To facilitate the design process, we present an abstraction model that formalizes the main geometric constraints imposed by fabrication and assembly, and incorporates conditions on the rigidity of the resulting structure. We show that the tight coupling of constraints makes manual design highly nontrivial and introduce an optimization method to automate constraint satisfaction based on an analysis of the constraint relation graph. This algorithm ensures that the planar parts can be fabricated and assembled. We demonstrate the versatility of our approach by creating 3D toy models, an architectural design study, and several examples of functional furniture

Fabrication-Aware Design with Performative Criteria

Artists and architects often need to handle multiple constraints during design of physical constructions. We define a performative constraint as any constraint on design that is tied to the performance of the model--either during fabrication, construction, daily use, or destruction. Even for small to medium scale models, there are functional criteria such as the ease of fabrication and the assembly process, or even the interplay of light with the material. Computational tools can greatly aid in this process, assisting with the lower-level performative constraints, while the designer handles the high-level artistic decisions. Additionally, using new fabrication methods, our tools can aid in lowering the difficulty of building complex constructions, making them accessible to hobbyists. In this thesis, we present three computational methods for designing with different approaches, each with a different material, fabrication method, and use case. The first method is a construction with intersecting planar pieces that can be laser cut or milled. These 3D forms are assembled by sliding pieces into each other along straight slits, and do not require other support such as glue or screws. We present a mathematical abstraction that formalizes the constraints between pieces as a graph, including fabrication and assembly constraints, and ensure global rigidity of the sculpture. We also propose an optimization algorithm to guide the user using automatic constraint satisfaction based on analysis of the constraint relation graph. We demonstrate our approach by creating several small- to medium-scale examples including functional furniture. The second method presents a solution to building a 3D sculpture out of existing building blocks that can be found in many homes. Starting from the voxelization of a 3D mesh we merge voxels to form larger bricks, and then analyze and repair structural problems based on a graph representation of the block connections. We then output layer-by-layer building instructions to allow a user to quickly and easily build the model. We also present extensions such as hollowing the models to use less bricks, limiting the number of bricks of each size, and including color constraints. We present both real and virtual brick constructions and associated timings, showing improvements over previous work. The final case presented tackles the inverse design problem of finding a surface to produce a target caustic on a receiver plane when light is refracted or reflected. This is an example where the performative constraint is the principal driver of the design. We introduce an optimal transport formulation to find a correspondence between the incoming light and the output target light distribution. We then show a 3D optimization that finds the surface that transports light based on the correspondence map. Our approach supports piecewise smooth surfaces that are as smooth as possible but allow for creases, to greatly reduce the amount of artifacts while allowing light to be completely diverted producing completely black regions. We show how this leads to a very large space of high-contrast, high-resolution caustic images, including point and line singularities of infinite light density as well as photo-realistic images. Our approach leads to surfaces that can be milled using standard CNC milling. We demonstrate the approach showing both simulated and fabricated examples

Towards Zero-Waste Furniture Design

In traditional design, shapes are first conceived, and then fabricated. While this decoupling simplifies the design process, it can result in inefficient material usage, especially where off-cut pieces are hard to reuse. The designer, in absence of explicit feedback on material usage remains helpless to effectively adapt the design -- even though design variabilities exist. In this paper, we investigate {\em waste minimizing furniture design} wherein based on the current design, the user is presented with design variations that result in more effective usage of materials. Technically, we dynamically analyze material space layout to determine {\em which} parts to change and {\em how}, while maintaining original design intent specified in the form of design constraints. We evaluate the approach on simple and complex furniture design scenarios, and demonstrate effective material usage that is difficult, if not impossible, to achieve without computational support

Metodología BIM en el grado de edificación: modelo de taller en la asignatura Expresión Gráfica de Tecnologías

El concepto de BIM implica un cambio radical en la manera de afrontar el diseño arquitectónico y el proceso de ciclo de vida de los proyectos y de los edificios. Se trata de un sistema eficiente y abierto de comunicación y cooperación entre los distintos operadores que intervienen en el proceso constructivo y, por tanto, resulta ser una herramienta idónea para su implantación en las Escuelas Técnicas de Ingeniería y Arquitectura. Este artículo defiende el reconocimiento de la metodología BIM como instrumento de trabajo colaborativo y coordinado para su aplicación en la docencia universitaria en titulaciones de esta rama de conocimiento, a fin de que el flujo de información interdisciplinar sea eficiente. Se describe la experiencia de la implantación de esta metodología en el Grado de Edificación, a través de un modelo de taller-integrador en la asignatura de Expresión Gráfica de Tecnologías. Posteriormente, se recogen averiguaciones docentes derivadas de la innovación desarrollada, mostrando sus beneficios para el estudiantado a nivel de aprendizaje y las limitaciones halladas. Con todo, los resultados obtenidos llevan a seguir apostando por esta integración tecnológica. Finalmente, para la mejora de esta innovación, se aportan una serie de recomendaciones en lo relativo a la manera de guiar al alumnado en la experiencia y relacionadas con la organización de las enseñanzas a través de sus planes de estudios.The concept of BIM implies a radical change in the way of facing the architectural design and the life cycle process of the projects and the buildings. It is an efficient and open system of communication and cooperation between the different operators involved in the construction process and, therefore, it becomes in a suitable tool for its implementation in the Technical Schools of Engineering and Architecture. This paper defends the recognition of the BIM methodology as a collaborative and coordinated instrument for its application in the university teaching in degrees of this field of knowledge, so that the flow of interdisciplinary information is efficient. The experience of the implementation of this methodology in the Degree in Building is described. It is based on a workshop-integrator model in the subject called Graphic Expression of Technologies. Subsequently, educational enquiries derived from the innovation developed are collected, showing its benefits for the student body as regards learning, and also the limitations found. In conclusion, the outcomes obtained lead to continue supporting this technological integration. Finally, a series of recommendations for its improvement are provided, concerning the way to guide the students throughout the experience, and also related to the teaching organisation through the curriculum

Boxelization: folding 3D objects into boxes

We present a method for transforming a 3D object into a cube or a box using a continuous folding sequence. Our method produces a single, connected object that can be physically fabricated and folded from one shape to the other. We segment the object into voxels and search for a voxel-tree that can fold from the input shape to the target shape. This involves three major steps: finding a good voxelization, finding the tree structure that can form the input and target shapes' configurations, and finding a non-intersecting folding sequence. We demonstrate our results on several input 3D objects and also physically fabricate some using a 3D printer

ACM Transactions on Graphics

We present a computational approach for designing CurveUps, curvy shells that form from an initially flat state. They consist of small rigid tiles that are tightly held together by two pre-stretched elastic sheets attached to them. Our method allows the realization of smooth, doubly curved surfaces that can be fabricated as a flat piece. Once released, the restoring forces of the pre-stretched sheets support the object to take shape in 3D. CurveUps are structurally stable in their target configuration. The design process starts with a target surface. Our method generates a tile layout in 2D and optimizes the distribution, shape, and attachment areas of the tiles to obtain a configuration that is fabricable and in which the curved up state closely matches the target. Our approach is based on an efficient approximate model and a local optimization strategy for an otherwise intractable nonlinear optimization problem. We demonstrate the effectiveness of our approach for a wide range of shapes, all realized as physical prototypes

ACM Transactions on Graphics

We present FlexMolds, a novel computational approach to automatically design flexible, reusable molds that, once 3D printed, allow us to physically fabricate, by means of liquid casting, multiple copies of complex shapes with rich surface details and complex topology. The approach to design such flexible molds is based on a greedy bottom-up search of possible cuts over an object, evaluating for each possible cut the feasibility of the resulting mold. We use a dynamic simulation approach to evaluate candidate molds, providing a heuristic to generate forces that are able to open, detach, and remove a complex mold from the object it surrounds. We have tested the approach with a number of objects with nontrivial shapes and topologies

Metodología BIM en el grado de edificación: modelo de taller en la asignatura Expresión Gráfica de Tecnologías

The concept of BIM implies a radical change in the way of facing the architectural design and the life cycle process of the projects and the buildings. It is an efficient and open system of communication and cooperation between the different operators involved in the construction process and, therefore, it becomes in a suitable tool for its implementation in the Technical Schools of Engineering and Architecture. This paper defends the recognition of the BIM methodology as a collaborative and coordinated instrument for its application in the university teaching in degrees of this field of knowledge, so that the flow of interdisciplinary information is efficient. The experience of the implementation of this methodology in the Degree in Building is described. It is based on a workshop-integrator model in the subject called Graphic Expression of Technologies. Subsequently, educational enquiries derived from the innovation developed are collected, showing its benefits for the student body as regards learning, and also the limitations found. In conclusion, the outcomes obtained lead to continue supporting this technological integration. Finally, a series of recommendations for its improvement are provided, concerning the way to guide the students throughout the experience, and also related to the teaching organisation through the curriculum