From 3D Models to 3D Prints: an Overview of the Processing Pipeline <s> Mass distribution <s> This paper introduces a design and fabrication pipeline for creating floating forms. Our method optimizes for buoyant equilibrium and stability of complex 3D shapes, applying a voxel-carving technique to control the mass distribution. The resulting objects achieve a desired floating pose defined by a user-specified waterline height and orientation. In order to enlarge the feasible design space, we explore novel ways to load the interior of a design using prefabricated components and casting techniques. 3D printing is employed for high-precision fabrication. For larger scale designs we introduce a method for stacking lasercut planar pieces to create 3D objects in a quick and economic manner. We demonstrate fabricated designs of complex shape in a variety of floating poses. <s> BIB001 </s> From 3D Models to 3D Prints: an Overview of the Processing Pipeline <s> Mass distribution <s> Spinning tops and yo-yos have long fascinated cultures around the world with their unexpected, graceful motions that seemingly elude gravity. Yet, due to the exceeding difficulty of creating stably spinning objects of asymmetric shape in a manual trial-and-error process, there has been little departure from rotationally symmetric designs. With modern 3D printing technologies, however, we can manufacture shapes of almost unbounded complexity at the press of a button, shifting this design complexity toward computation. ::: In this article, we describe an algorithm to generate designs for spinning objects by optimizing their mass distribution: as input, the user provides a solid 3D model and a desired axis of rotation. Our approach then modifies the interior mass distribution such that the principal directions of the moment of inertia align with the target rotation frame. To create voids inside the model, we represent its volume with an adaptive multiresolution voxelization and optimize the discrete voxel fill values using a continuous, nonlinear formulation. We further optimize for rotational stability by maximizing the dominant principal moment. Our method is well-suited for a variety of 3D printed models, ranging from characters to abstract shapes. We demonstrate tops and yo-yos that spin surprisingly stably despite their asymmetric appearance. <s> BIB002
The distribution of material and cavities inside a 3D printed model has been the subject of recent research. In [PWLSH13] a method to optimize the balance of a shape to make it stand in a given pose is proposed. The work was further extended in BIB002 , where a novel optimization of the mass distribution to make an abject spinnable around a given axis was proposed. The optimization of the buoyant equilibrium is the subject of BIB001 , where a method to create floating objects in a prescribed pose is presented. In [PB-JSH16] the authors consider the standing, suspension, and immersion balancing problems for 3D printed objects containing embedded movable masses. In [WKW16, MAB * 15] unified frameworks for the optimal interior design and mass distribution of 3D printed objects that enable the optimization of static, rotational and buoyant equilibrium are presented. Recent research has pushed this concept even further. In [MHR * 16] the shape design is posed as non-linear problem that aims to optimize the natural frequencies of a shape, for example to make it sound in a controlled manner, as a musical instrument.