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Recent virtual grasping approaches involve physical simulation and virtual couplings between tracked and virtual hand configurations. We introduce a nonuniform coupling in which the stiffness of thumb coupling is scaled relative to that of other digits. This shifts the position of grasped objects in the hand, which may impact grasp and release performance.(More)
This paper presents a three-level tracker calibration system that greatly reduces errors in tracked position and orientation. The first level computes an error-minimizing rigid body transform that eliminates the need for precise alignment of a tracker base frame. The second corrects for field warp by interpolating correction values stored with vertices in a(More)
We present and evaluate a new approach for real-time rendering of composable 3D lenses for polygonal scenes. Such lenses, usually called ¿volumetric lenses,¿ are an extension of 2D Magic Lenses to 3D volumes in which effects are applied to scene elements. Although the composition of 2D lenses is well known, 3D composition was long considered infeasible due(More)
We present a haptic feedback technique that combines feedback from a portable force-feedback glove with feedback from direct contact with rigid passive objects. This approach is a haptic analogue of visual mixed reality, since it can be used to haptically combine real and virtual elements in a single display. We discuss device limitations that motivated(More)
We investigate predictive coding for reducing the amount of data communicated between a haptic controller and a host. This allows increased update rate, which potentially improves quality even if coding is lossy. A low-order predictive coding is investigated for a pneumatic force display. Due to human and device characteristics, some compression is possible(More)
We present a framework, example application, and rendering methods for volumetric windows, a 3D analog of the 2D windows metaphor. A set of parameters reflected in both implementation and user menus allows windows to behave like 3D volumetric lenses, clip windows, world-in-miniature views, and in other ways. We use programmable hardware shaders to render(More)
We present the first experiment on tradeoffs involving visual interpenetration in whole-hand virtual grasping, with new findings that contrast prior interpenetration research and provide a stronger understanding of user behavior and beliefs. Most notably, preventing interpenetration reduced performance by increasing real hand closure and reducing release(More)