From Digital to Physical: Computational Aspects of 3D Manufacturing


􏰦The desktop publishing revolution of the 􏰟􏰫􏰪􏰞s is currently repeating itself in 􏰠3D, referred to as desktop manufacturing. Online services such as Shapeways have become available, making personalized manufacturing on cutt􏰥ing edge additive manufacturing (AM) technologies accessible to a broad audience. Affordable desktop printers will soon take over, enabling people to fabricate custom 3􏰠D models at home. Contemporary AM technologies have advanced enough to enable 3􏰠D printing at high resolution, in full-color, and with mixtures of soft and hard materials. As opposed to subtractive manufacturing (SM) such as milling or drilling, they can fabricate highly complex assemblies without the need for a manual assembly of individual components. Yet, one of the major issues holding back widespread use of AM is the lack of efficient algorithms for the automated fabrication of digital CG, and the reproduction of physical content. Besides, we do not have tools at our disposal that aid us with the design of multi-material content or complex assembly structures. For physical reproduction, we strive for methods to acquire properties such as, e.g., reflectance (appearance) or elasticity (deformation behavior) from real-world objects, representing them digitally, then automating their fabrication using AM. However, the vast majority of digital 3􏰠D content are directly designed on computers, hence, potentially exhibit a highly non-physical behavior. To fabricate such content, we seek methods for the automated estimation of physical models from these digital ones. 􏰦This dissertation examines computational aspects of 􏰠3D manufacturing. In particular, we investigate design tools and automated fabrication of an object’s deformation behavior, articulation, and geometry. We present a complete process for measuring, representing, simulating, and physically fabricating an object’s elastic deformation behavior. Th􏰦is process enables the reproduction of physical deformation behavior. Furthermore, we introduce a technique for the automated fabrication of articulated models, estimated from the most widely used format in character animation – so called skinned meshes. Our technique estimates assemblies, approximating this inherently non-physical input in a piecewise linear manner. Lastly, we propose a method for the scale-aware fabrication of static geometry, capable of abstracting, then engraving details that cannot be fabricated on a pre-specified 3􏰠D printer.

PhD Thesis