Steering a cursor through a constrained path is required for operating graphical user interfaces, such as when navigating a cascaded menu. Recently, the accuracy with which users successfully accomplish a task is emerging as an important performance indicator. In this study, we evaluated the performance of a Servo-Gaussian model to predict the success rates in linear and circular paths with 212 and 166 crowdsourced participants, respectively. The results showed that, for linear paths, the model achieved r2=0.9676, MAE=2.036%, and RMSE=2.692%, and for circular paths, it achieved r2=0.9787, MAE=3.199%, and RMSE=3.927%. Shuffle-split cross-validation with five train-test data-size ratios also demonstrated the robust prediction accuracy of the model. These findings will provide designers with a useful tool to judge if an interface can be accurately operated without running costly user studies for new task conditions.

Within the domain of fabrication, the recent strides in Fused Deposition Modeling (FDM) have sparked growing interest in its sustainability. In this work, we analyze the contemporary lifecycle of polymers consumed in FDM, a common and accessible fabrication technique. Then we outline the points of design intervention to reduce wasted polymers in fabrication. Specifically, we discuss the design intervention of Filament Wiring , a set of hybrid craft techniques to promote sustainable prototyping and robust applications by highlighting left-over filaments. Our techniques aim to enhance the understanding of filaments as a unique material for hybrid fabrication, fostering creativity. Through our computational design system, end users can generate 3D printable frames, for exploring the possibilities of filament-based fabrication beyond 3D printing. We hope to provoke thought about filament as its own form of material, having capabilities to be made, unmade, and remade repeatedly into various artifacts. With this outlook, we discuss future research avenues and urge makers and practitioners to value material in any form, quantity, or stage of its lifecycle.

Hand-weaving is a beloved craft in history, holding promise for many opportunities in making from flat sheet fabrics to smart textiles. To afford new weaving experiences, we explore how 3D printed custom weaving tools interplay with different materiality, augmenting the design space of weaving. We propose novel weaving techniques enabled by 3D printed custom tools: (1) water-soluble draft to synchronize design intention and practice, (2) flexible warps to guide complex patterns and to shape resulting object, and (3) rigid global geometry for woven artifacts in 3D. EscapeLoom as a computational design tool enables users to employ various parameters in their computational design, and showcases many creative possibilities that move away from the traditional definition of a loom to dive into what more it can be.

The steering law is a model for predicting the time and speed for passing through a constrained path. When people can view only a limited range of the path forward, they limit their speed in preparation of possibly needing to turn at a corner. However, few studies have focused on how limited views affect steering performance, and no quantitative models have been established. The results of a mouse steering study showed that speed was linearly limited by the path width and was limited by the square root of the viewable forward distance. While a baseline model showed an adjusted R2 = 0.144 for predicting the speed, our best-fit model showed an adjusted R2 = 0.975 with only one additional coefficient, demonstrating a comparatively high prediction accuracy for given viewable forward distances.

From full-color objects to functional capacitive artifacts, 3D printing multi-materials became essential to broaden the application areas of digital fabrication. We present Programmable Filament, a novel technique that enables multi-material printing using a commodity FDM 3D printer, requiring no hardware upgrades. Our technique builds upon an existing printing technique in which multiple filament segments are printed and spliced into a single threaded filament. We propose an end-to-end pipeline for 3D printing an object in multi-materials, with an introduction of the design systems for end-users. Optimized for low-cost, single-nozzle FDM 3D printers, the system is built upon our computational analysis and experiments to enhance its validity over various printers and materials to design and produce a programmable filament. Finally, we discuss application examples and speculate the future with its potential, such as custom filament manufacturing on-demand.

We propose a Servo-Gaussian model to predict success rates in continuous manual tracking tasks. Two tasks were conducted to validate this model: path steering and pursuit of a 1D moving target. We hypothesized that (1) hand movements follow the servo-mechanism model, (2) submovement endpoints form a bivariate Gaussian distribution, thus enabling us to predict the success rate at which a submovement endpoint falls inside the tolerance, and (3) the success rate for a whole trial can be predicted if the number of submovements is known. The cross-validation showed R^2>0.92 and MAE<4.9% for steering and R^2>0.95 and MAE<6.5% for pursuit tasks. These results demonstrate that our proposed model delivers high prediction accuracy even for unknown datasets.

The emergence of a 3D pen brings 3D modeling from a screen-based computer-aided design (CAD) system and 3D printing to direct and rapid crafting by 3D doodling. However, 3D doodling remains challenging, requiring craft skills to rapidly express an idea, which is critical in creative making. We explore a new process of 3D modeling using 3D pen + 3D printer. Our pilot study shows that users need support to reduce the number of non-creative tasks to explore a wide design strategy. With the opportunity to invent a new 3D modeling process that needs to incorporate both a pen and printer, we propose techniques and a system that empower users to print while doodling to focus on creative exploration. Our user study shows that users can create diverse 3D models using a pen and printer. We discuss the roles of the human and fabrication machine for the future of fabrication.

We present a technique for fabricating soft and flexible textiles using a consumer grade fused deposition modeling (FDM) 3D printer. By controlling the movement of the print header, the FDM alternately weaves the stringing fibers across a row of pillars. Owing to the structure of the fibers, which supports and strengthens the pillars from each side, a 3D printer can print a thin sheet of fabric in an upright position while the fibers are being woven. In addition, this technique enables users to employ materials with various colors and/or properties when designing a pattern, and to prototype an interactive object using a variety of off-the-shelf materials such as a conductive filament. We also describe a technique for weaving textiles and introduce a list of parameters that enable users to design their own textile variations. Finally, we demonstrate examples showing the feasibility of our approach as well as numerous applications integrating printed textiles in a custom object design.

Fused deposition modeling (FDM) 3D printers form objects by stacking layers having a linear structure. To print fine structures, an appropriate choice of parameters is necessary, or printing error occurs. On the other hand, the printing error is exploited as an expression technique. However, the relation between the printed structure and the parameters causing the printing error is unclear. In this paper, we focus on the height position of the extruder and the amount of extruded material, and explore the combination of these parameters to enhance the capability of FDM. By extending an equation that calculates the amount of material from the layer height, we investigate the behavior and structure of material extruded from various height positions. On the basis of experimental results, the printed structure is classified into six categories according to the structural feature. We describe these structural features and demonstrate examples with new inherent expressions for FDM.