Felipe Bacim

Rapid and accurate 3D selection by progressive refinement

Issues such as hand and tracker jitter negatively affect user performance with the ray-casting selection technique in 3D environments. This makes it difficult for users to perform tasks that require them to select objects that have a small visible area, since small targets require high levels of precision. We introduce an approach to address this issue that uses progressive refinement of the set of selectable objects to reduce the required precision of the task. We present a design space of progressive refinement techniques and an exemplar technique called Sphere-casting refined by QUAD-menu (SQUAD). We explore the tradeoffs between progressive refinement and immediate selection techniques in an evaluation comparing SQUAD to ray-casting. Both an analytical evaluation based on a distal pointing model and an empirical evaluation demonstrate that progressive refinement selection can be better than immediate selection. SQUAD was much more accurate than ray-casting, and SQUAD was faster than ray-casting with small targets and less cluttered environments.

Human-robot Teaming for Rescue Missions: Team ViGIR's Approach to the 2013 DARPA Robotics Challenge Trials

Team ViGIR entered the 2013 DARPA Robotics Challenge DRC with a focus on developing software to enable an operator to guide a humanoid robot through the series of challenge tasks emulating disaster response scenarios. The overarching philosophy was to make our operators full team members and not just mere supervisors. We designed our operator control station OCS to allow multiple operators to request and share information as needed to maintain situational awareness under bandwidth constraints, while directing the robot to perform tasks with most planning and control taking place onboard the robot. Given the limited development time, we leveraged a number of open source libraries in both our onboard software and our OCS design; this included significant use of the robot operating system libraries and toolchain. This paper describes the high level approach, including the OCS design and major onboard components, and it presents our DRC Trials results. The paper concludes with a number of lessons learned that are being applied to the final phase of the competition and are useful for related projects as well.

Design and evaluation of 3D selection techniques based on progressive refinement

Issues such as hand and tracker jitter negatively affect user performance with 3D selection techniques based on the ray-casting metaphor. This makes it difficult for users to select objects that have a small visible area, since small targets require high levels of precision. We introduce an approach to address this issue that uses progressive refinement of the set of selectable objects to reduce the required precision of the task. We present three exemplar techniques (sphere-casting refined by QUAD menu (SQUAD), discrete zoom, and continuous zoom) and derive a preliminary design space for progressive refinement from their characteristics. We explore the trade-offs between progressive refinement and immediate selection techniques in two studies: first comparing SQUAD to ray-casting; and second comparing the zooming techniques to ray-casting. In both studies, an analytical evaluation based on a distal pointing model and an empirical evaluation demonstrates that progressive refinement selection can provide significant benefits compared to immediate techniques. In the first study, SQUAD was much more accurate than ray-casting, and SQUAD was faster than ray-casting with small targets and less cluttered environments. The issue with SQUAD, however, is that it requires all selectable objects to be visually distinct. The zooming techniques address this issue by exploring other areas of the progressive refinement design space. They allow users to use the spatial relationships among objects as criteria for selection and to increase precision without requiring precision in pointing. The results of the second study show that while the zooming techniques were significantly slower than ray-casting, accuracy was much higher. Additionally, depending on the size of the target, users chose not to use zoom and, therefore, performed as fast as with ray-casting.

Slice-n-Swipe: A free-hand gesture user interface for 3D point cloud annotation

Three-dimensional point clouds are generated by devices such as laser scanners and depth cameras, but their output is a set of unstructured, unlabeled points. Many scenarios require users to identify parts of the point cloud through manual annotation. Inspired by the current generation of “natural user interface” technologies, we present Slice-n-Swipe, a technique for 3D point cloud annotation based on free-hand gesture input. The technique is based on a chefs knife metaphor, and uses progressive refinement to allow the user to specify the points of interest. We demonstrate the Slice-n-Swipe concept with a prototype using the Leap Motion Controller for free-hand gesture input and a 3D mouse for virtual camera control.

Overview of team ViGIR's approach to the Virtual Robotics Challenge

With the DARPA Robotics Challenge (DRC), a call to an ambitious multi-part competition was sent out to the robotics community. In this paper, we briefly summarize the approach for addressing the Virtual Robotics Challenge (VRC) where software for control and supervision of a capable humanoid robot must be developed. Team ViGIR, comprising members from the US and Germany, leveraged previous robotics competition experience and a variety of open source tools, to achieve sixth place in the VRC out of 126 registrants, thereby advancing to the next round of the DRC and obtaining an Atlas robot.

Cognitive scaffolding in Web3D learning systems: a case study for form and structure

In this paper, we describe a case study in usability engineering for Web3D learning systems and introduce a new step to the typical methods of the usability design. Pedagogical applications present a challenge to the usual usability engineering process in that the end-users of the system (students) cannot describe the requirements of the system. For this situation, we engage the latest evidence and principles of cognition to help map requirements to information design for an interactive learning system. Our system seeks to improve the structural understanding of architects and to teach relationships between form and structure in long-span systems. We provide both explanatory multimedia resources and interactive resources including a Web-based modeling and simulation tool that aids architecture students with better understanding of the relationship between structure and form in design. We describe our design process and the system and examine the qualitative impact of the cognitive ergonomic process. This extra step in the usability design process of mapping expert knowledge to human perception and cognition can increase awareness of the requirements of a learning system and improve the effectiveness of the subsequent design.

Amplified Head Rotation in Virtual Reality and the Effects on 3D Search, Training Transfer, and Spatial Orientation

Many types of virtual reality (VR) systems allow users to use natural, physical head movements to view a 3D environment. In some situations, such as when using systems that lack a fully surrounding display or when opting for convenient low-effort interaction, view control can be enabled through a combination of physical and virtual turns to view the environment, but the reduced realism could potentially interfere with the ability to maintain spatial orientation. One solution to this problem is to amplify head rotations such that smaller physical turns are mapped to larger virtual turns, allowing trainees to view the entire surrounding environment with small head movements. This solution is attractive because it allows semi-natural physical view control rather than requiring complete physical rotations or a fully-surrounding display. However, the effects of amplified head rotations on spatial orientation and many practical tasks are not well understood. In this paper, we present an experiment that evaluates the influence of amplified head rotation on 3D search, spatial orientation, and cybersickness. In the study, we varied the amount of amplification and also varied the type of display used (head-mounted display or surround-screen CAVE) for the VR search task. By evaluating participants first with amplification and then without, we were also able to study training transfer effects. The findings demonstrate the feasibility of using amplified head rotation to view 360 degrees of virtual space, but noticeable problems were identified when using high amplification with a head-mounted display. In addition, participants were able to more easily maintain a sense of spatial orientation when using the CAVE version of the application, which suggests that visibility of the users body and awareness of the CAVEs physical environment may have contributed to the ability to use the amplification technique while keeping track of orientation.

Collaborative navigation in virtual search and rescue

Disaster relief responders aim to quickly locate and extract survivors from dangerous environments. This research explores the use of a collaborative guidance system for search-and-rescue in a complex building. We implemented and evaluated a proof-of-concept system that allowed a scene commander and responder to efficiently search a building using visual, nonverbal communication. Participants found the interface to be both intuitive and fun, and results suggest that the collaborative navigation system was effective.

3DUI 2010 Contest Grand Prize Winners

The 2010 IEEE Symposium on 3D User Interfaces ran the symposiums first 3DUI Grand Prize, a contest for innovative, practical solutions to classic 3DUI problems. The authors describe the rationale for the first contest and give an analysis of all submissions. Each categorys winners also discuss their solutions.

Wayfinding techniques for multiScale virtual environments

Wayfinding in multiscale virtual environments can be rather complex, as users can and sometimes have to change their scale to access the entire environment. Hence, this work focuses on the understanding and classification of information needed for travel, as well as on the design of navigation techniques that provide this information. To this end, we first identified two kinds of information necessary for traveling effectively in this kind of environment: hierarchical information, based on the hierarchical structure formed by the levels of scale; and spatial information, related to orientation, distance between objects in different levels of scale and spatial localization. Based on this, we designed and implemented one technique for each kind of information. The developed techniques were evaluated and compared to a baseline set of travel and wayfinding aid techniques for traveling through multiple scales. Results show that the developed techniques perform better and provide a better solution for both travel and wayfinding aid.