James S. Lipscomb

Making nested rotations convenient for the user

Subimage motion in a three-dimensional computer graphic system is much easier for the user to control if the subimage moves the same direction as his hand while he manipulates the control device. The implementation of such coordinated motion of hand and subimage implies modification of the normal procedure for calculating transformations. The convenience of such manipulation also depends on appropriate selection or design of the input device. This paper reviews the relevant attributes of locator devices and presents an approach to selection. It presents the mathematics of transformation nesting and “compensation” to preserve motionsynchrony. Finally, it offers a case history of an interactive graphic system whose human factors were improved by these techniques.

Interactive simulation in a multi-person virtual world

A multi-user Virtual World has been implemented combining a flexible-object simulator with a multisensory user interface, including hand motion and gestures, speech input and output, sound output, and 3-D stereoscopic graphics with head-motion parallax. The implementation is based on a distributed client/server architecture with a centralized Dialogue Manager. The simulator is inserted into the Virtual World as a server. A discipline for writing interaction dialogues provides a clear conceptual hierarchy and the encapsulation of state. This hierarchy facilitates the creation of alternative interaction scenarios and shared multiuser environment.

A trainable gesture recognizer

Abstract Gestures are hand-drawn strokes that do things. These things happen at distinctive places on the stroke. We built a gesture input filter and recognizer. The input filter is fast, because it does few computations per input point, because it can omit pre-filter data smoothing, and because wild points caused by hardware glitches are removed at the few output points of the filter, not at the many input points. The recognizer is a novel combination of two traditional techniques; angle filtering and multiscale recognition. Because an angle filter does not produce well-behaved scaled output, the multi-scale treatment had to be unusual.

Reducing crosstalk between stereoscopic views

Crosstalk between the left and right eyes consists of the one eyes image seen faintly by the other. Image processing can reduce this. The technique is effective, but there are costs of course, and some surprises.

The HotMedia architecture: progressive and interactive rich media for the Internet

HotMedia is a novel scalable solution for delivering interactive rich media over the Internet. It is a delivery-suitable file format that can contain heterogeneous compositions of media bit streams as well as meta-data that define the behavior, composition, and interaction semantics. This enables the creation of lightweight single-file representations of interactive, multiphase presentations involving multiple media-type content. The HotMedia client has a smart content algorithm that infers types from the incoming data stream and fetches the media renderer components, user-interface components, and hyper-linked action components, all just-in-time, resulting in progressive and contest driven enrichment of the user experience. Internet users get a simple initial experience with minimal latency followed by enrichment of this experience. HotMedia has an open and extensible architecture, which enables and encourages the inclusion of new media-types, user-interfaces, and hyper-linked actions. By separating media-rendering from action-performing, it lets all media handle the same actions. HotMedia can also track on the server-side, user interactions and user-experience associated parameters. In its simplest usage HotMedia requires no more than a regular web server for delivery and no client-side preinstallation.

Analog input device physical characteristics

When selecting a device, a designer should compare alternative devices point-by-point. When making a tentative decision, one needs to know what other possibilities have been locked out. A classification graph does this.New here is this classification graph. Also new are several terms: free, sticky, unbounded, bounded, homogeneous and volatile.We developed this classification of existing devices while building the GRIP-75 interactive molecular computer graphics system [2, 11] and refined the classification during discussions with other system builders where we used this classification to map out alternatives. This paper is founded on practice and experience, not on classification theory.

An integrated live interactive content insertion system for digital TV commerce

We present an advanced architecture for selectively inserting interactive content into a live TV broadcast anti tracking the usage of the inserted content by client viewers. Specifically, we propose a multi-level interactive content preview mechanism, agent-based information exchange mechanism and E-commerce enablement technology powered by an Interactive Content Creation Engine (ICCE). Also, we introduce two types of mapping lists for scheduling and for an intelligent decision maker based oil the transaction monitoring and multi-level content preview. We propose that the improved live interactive content insertion method and system will be especially useful for building interactive TV e-commerce solutions.

Reversed apparent movement and erratic motion with many refreshes per update

Image quality in refresh computer graphics is degraded when the image is in motion but not being moved across the screen once with each refresh. Multiple images, reversed apparent movement, jerky motion, and erratic motion can be the result.These problems were faced during the construction of GRIP-75, a vector graphics molecular modeling system.

A visit to the dresden frauenkirche

The Frauenkirche was destroyed when Dresden was bombed by the Allied forces February 13-14, 1945. The church is now being reconstructed in an effort led by the Foundation for the Reconstruction of the Frauenkirche. The VRDECK software package developed at the IBM T. J. Watson Research Center was used to view and walk through a model created from the original church plans. A Polhemus tracker and a custom-built joystick using the Logitech 3D mouse were used for six-degree-of-freedom input to the application. The interactive fly-through of the church is in an immersive environment. One can navigate around the model wearing a head-mounted display, sitting in front of a standard monitor, looking at a stereo image produced on a stereo monitor, or standing before a projection screen displaying a stereo image of the scene. The system was developed for and exhibited at the IBM booth in the CeBIT fair in Hannover, Germany in March 1994 with funding from IBM Germany.

Experience with Stereoscopic Display Devices and Output Algorithms

Unobtrusiveness seems much more important than price or image quality to high-end workstation stereo users. Polarizing plate technology freed our users to concentrate better on their application. Unobtrusiveness seems to he important in the marketplace too, since the polarizing plate is selling well despite a price 2-3 times that of similar active glasses installations. These observations come from watching chemists at the University of North Carolina at Chapel Hill as they used molecular computer graphics with many stereo display devices. The output algorithm of rotation to produce stereo is well known to be wrong for the perspective case, but correct for the non-perspective (orthographic) case. However, a shear is better for orthographic stereo, because it correctly handles clipping planes on some graphics hardware, and it is faster to compute than a rotation. A shear creates the illusion that transformations order is reversed.