Karl D.D. Willis

Printed optics: 3D printing of embedded optical elements for interactive devices

We present an approach to 3D printing custom optical elements for interactive devices labelled Printed Optics. Printed Optics enable sensing, display, and illumination elements to be directly embedded in the casing or mechanical structure of an interactive device. Using these elements, unique display surfaces, novel illumination techniques, custom optical sensors, and embedded optoelectronic components can be digitally fabricated for rapid, high fidelity, highly customized interactive devices. Printed Optics is part of our long term vision for interactive devices that are 3D printed in their entirety. In this paper we explore the possibilities for this vision afforded by fabrication of custom optical elements using todays 3D printing technology.

Interactive fabrication: new interfaces for digital fabrication

We present a series of prototype devices that use real-time input to fabricate physical form: Interactive Fabrication. Our work maps out the problem space of real-time control for digital fabrication devices, and examines where alternative interfaces for digital fabrication are relevant. We conclude by reflecting upon the potential of interactive fabrication and outline a number of considerations for future research in this area.

SideBySide: ad-hoc multi-user interaction with handheld projectors

We introduce SideBySide, a system designed for ad-hoc multi-user interaction with handheld projectors. SideBySide uses device-mounted cameras and hybrid visible/infrared light projectors to track multiple independent projected images in relation to one another. This is accomplished by projecting invisible fiducial markers in the near-infrared spectrum. Our system is completely self-contained and can be deployed as a handheld device without instrumentation of the environment. We present the design and implementation of our system including a hybrid handheld projector to project visible and infrared light, and techniques for tracking projected fiducial markers that move and overlap. We introduce a range of example applications that demonstrate the applicability of our system to real-world scenarios such as mobile content exchange, gaming, and education.

Motionbeam: a metaphor for character interaction with handheld projectors

We present the MotionBeam metaphor for character interaction with handheld projectors. Our work draws from the tradition of pre-cinema handheld projectors that use direct physical manipulation to control projected imagery. With our prototype system, users interact and control projected characters by moving and gesturing with the handheld projector itself. This creates a unified interaction style where input and output are tied together within a single device. We introduce a set of interaction principles and present prototype applications that provide clear examples of the MotionBeam metaphor in use. Finally we describe observations and insights from a preliminary user study with our system.

HideOut: mobile projector interaction with tangible objects and surfaces

HideOut is a mobile projector-based system that enables new applications and interaction techniques with tangible objects and surfaces. HideOut uses a device mounted camera to detect hidden markers applied with infrared-absorbing ink. The obtrusive appearance of fiducial markers is avoided and the hidden marker surface doubles as a functional projection surface. We present example applications that demonstrate a wide range of interaction scenarios, including media navigation tools, interactive storytelling applications, and mobile games. We explore the design space enabled by the HideOut system and describe the hidden marker prototyping process. HideOut brings tangible objects to life for interaction with the physical world around us.

Spatial sketch: bridging between movement & fabrication

Spatial Sketch is a three-dimensional (3D) sketch application that bridges between physical movement and the fabrication of objects in the real world via cut planar materials. This paper explores the rationale and details behind the development of the Spatial Sketch application, and presents our observations from user testing and a hands-on lamp shade design workshop. Finally we reflect upon the relevance of embodied forms of human computer interaction for use in digital fabrication.

InfraStructs: fabricating information inside physical objects for imaging in the terahertz region

We introduce InfraStructs, material-based tags that embed information inside digitally fabricated objects for imaging in the Terahertz region. Terahertz imaging can safely penetrate many common materials, opening up new possibilities for encoding hidden information as part of the fabrication process. We outline the design, fabrication, imaging, and data processing steps to fabricate information inside physical objects. Prototype tag designs are presented for location encoding, pose estimation, object identification, data storage, and authentication. We provide detailed analysis of the constraints and performance considerations for designing InfraStruct tags. Future application scenarios range from production line inventory, to customized game accessories, to mobile robotics.

Cilllia: 3D Printed Micro-Pillar Structures for Surface Texture, Actuation and Sensing

This work presents a method for 3D printing hair-like structures on both flat and curved surfaces. It allows a user to design and fabricate hair geometries that are smaller than 100 micron. We built a software platform to let users quickly define the hair angle, thickness, density, and height. The ability to fabricate customized hair-like structures not only expands the library of 3D-printable shapes, but also enables us to design passive actuators and swipe sensors. We also present several applications that show how the 3D-printed hair can be used for designing everyday interactive objects.

A pre-history of handheld projector-based interaction

I present a pre-history of contemporary handheld projector-based interaction to inform the design of future interactive systems. I begin by documenting the two main types of pre-cinema handheld projection from Europe and Japan, the handheld magic lantern and the utsushi-e performance. I then present a summary of projection techniques used by performers when interacting with these devices. I situate these techniques within contemporary research and illustrate how they are being used and built upon with contemporary technology. Finally, I discuss how knowledge of pre-cinema handheld projection devices, techniques, and performance can inform the design of future handheld projector systems.

MotionBeam: designing for movement with handheld projectors

In this paper we present a novel interaction metaphor for handheld projectors we label MotionBeam. We detail a number of interaction techniques that utilize the physical movement of a handheld projector to better express the motion and physicality of projected objects. Finally we present the first iteration of a projected character design that uses the MotionBeam metaphor for user interaction.