Time-critical domains, such as emergency management, demand fast decisions from expert users under stress. Our Decision-Centered Visualization (DCV) system supports decision making by integrating domain knowledge and knowledge about human situation awareness for time-critical visualization. Efficient information presentation is vital for the user's situation awareness and, in consequence, to his or her task performance. We address the problem of efficiently visualizing both existing and incoming information by connecting domain data types and presentation requirements of the domain's tasks.

Users of information systems in time-critical domains are under constant pressure to digest and process information that is vital for their task. Thus, the user needs efficient information visualization that avoids displaying information that is not vital at the moment. Decision-centered visualization is an adaptive, interactive visualization system that supports decision making by integrating domain knowledge and knowledge about human decision making with an interactive visualization architecture. An important facet of this system is the representation of the underlaying domain knowledge. We will first describe the main modules and the main structures of the knowledge representation of the DCV system. We then describe how DCV uses the represented domain knowledge to guide the information visualization in time-critical applications.

In many virtual environment (VE) applications, the VE system must be able to display accurate models of human figures that can perform routine behaviors and adapt to events in the virtual world. In order to achieve such adaptive, task‐level interaction with virtual actors, it is necessary to model elementary human motor skills. SkillBuilder is a software system for constructing a set of motor behaviors for a virtual actor by designing motor programs for arbitrarily complicated skills. Motor programs are modeled using finite state machines, and a set of state machine transition and ending conditions for modeling motor skills has been developed. Using inverse kinematics and automatic collision avoidance, SkillBuilder was used to construct a suite of behaviors for simulating visually guided reaching, grasping, and head‐eye tracking motions for a kinematically simulated actor consisting of articulated, rigid body parts. All of these actions have been successfully demonstrated in real time by permitting the user to interact with the virtual environment using a whole‐hand input device.

In this paper, a method of encapsulation camera tasks into well defined units called “camera modules” is described. Through this encapsulation, camera modules can be programmed and sequenced, and thus can be used as the underlying framework for controlling the virtual camera in the widely disparate types of graphical environments. Two examples of the camera framework are shown: an agent which can film a conversation between two virtual actors and a visual programming language for filming a virtual football game.

A disciplined investigation of "whole-hand interfaces (often glove based, currently) and their appropriate use for the control of complex task domains is embodied by the design method for whole-hand input.This is a series of procedures-including a common basis for the description, design, and evaluation of whole-hand input, together with an accompanying taxonomy-that enumerates key issues and points for consideration in the development of whole-hand input.The method helps designers focus on task requirements, isolate problem areas, and choose appropriate whole-hand input strategies for their specified tasks.Several experiments were conducted to validate and demonstrate the use of the design method.The results of the experiments are summarized and discussed.

This paper presents a general system for camera movement upon which a wide variety of higher-level methods and applications can be built.In addition to the basic commands for camera placement, a key attribute of the CINEMA system is the ability to inquire information directly about the 3D world through which the camera is moving.With this information high-level procedures can be written that closely correspond to more natural camera specifications.Examples of some high-level procedures are presented.In addition, methods for overcoming deficiencies of this procedural approach are proposed.

We have implemented a system for Computer-Aided Plastic Surgery.Planning plastic surgery procedures is complex because the surgeon needs to stretch and reshape the patient's skin to replace missing tissue while minimizing distortion of the surrounding tissue.Traditional planning techniques rely on the surgeon's experience to select among a myriad of possible procedure designs.While mathematica1 techniques for predicting the outcome of surgery have been proposed in the past, these are not in widespread use by surgeons because they require the surgeon to perform manual constructions and geometric calculations.Our system makes the analysis process easier by allowing the surgeon to draw the surgical plan directly on a 3D model of the patient.An automatic mesh generator is used to convert that drawing into a well-formulated problem for finite element analysis.

article Pump it up: computer animation of a biomechanically based model of muscle using the finite element method Share on Authors: David T. Chen Computer Graphics and Animation Group, The Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA Computer Graphics and Animation Group, The Media Laboratory, Massachusetts Institute of Technology, Cambridge, MAView Profile , David Zeltzer Computer Graphics and Animation Group, The Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA Computer Graphics and Animation Group, The Media Laboratory, Massachusetts Institute of Technology, Cambridge, MAView Profile Authors Info & Claims ACM SIGGRAPH Computer GraphicsVolume 26Issue 2July 1992 pp 89–98https://doi.org/10.1145/142920.134016Published:01 July 1992 176citation3,599DownloadsMetricsTotal Citations176Total Downloads3,599Last 12 Months42Last 6 weeks5 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Abstract As virtual worlds become increasingly complex,task levelinteraction with virtual actors becomes correspondingly important. The control problem simply becomes unmanageable if we try to interact with synthetic agents at the wrong level of abstraction. However, it is not sufficient merely to implement a set of behaviours for a virtual actor; we require some mechanism for selecting and sequencing motor skills appropriate to the current behavioural goalsandthe states of other objects and actors in the virtual environment. In this paper we will describe a mechanism for linkingperceptionandactionto generate routine behaviours in a process we callmotor planning.We present our implementation of the skill network, in which motor skills are the nodes and the arcs represent inhibitory and excitatory connections, including extensions to this architecture based on recent work in robotics. We characterize the domain of motor planning, i.e. what kinds of behaviour can it account for, and when will it fail? We close with a discussion of the limits of our current implementation and work that remains to be done.

We have developed a virtual environment system which supports multiple simulations, including virtual actors. These actors exhibit motor behavior in response to activity in the environment. We present an example actor, whose low-level behavior is modeled after physiological analyses of cockroach motor behavior. The sensori-motor activity of our roach is generated by a hierarchical control structure. Coupled oscillators generate basic gait patterns, which are modified by reflexes feeding in from the environment. Stepping and stance are executed by kinematic motor programs, which move the legs and body. The reactive level associates motor behavior with events in the virtual environment, to simulate perception and implement higher level behaviors. The activity of the virtual actor is determined only when it is situated in the environment, and interacts with the user and other simulations.

We have implemented an algorithm for rigid body dynamics which unifies the advantages of linear recursive algorithms with the advantages of earlier linear algebra based constraint force approaches. No restriction is placed on the joints between links. The algorithm is numerically robust and can deal with arbitrary trees of bodies, including kinematic loops. Motion as well as force constraints on the dynamic behavior of any member of the linkage can be added easily. Through the use of spatial algebra notation---including our extension to account for spatial position---the mathematical expressions are simplified and more efficient to execute. The algorithm has been implemented on workstation class machines and performs at interactive speeds.

Accurate simulation of Newtonian mechanics is essential for simulating realistic motion of joined figures. Dynamic simulation requires, however, a large amount of computation when compared to kinematic methods, and the control of dynamic figures can be quite complex. We have implemented an efficient forward dynamic simulation algorithm for articulated figures which has a computational complexity linear in the number of joints. In addition, we present a strategy for the coordination of the locomotion of a six-legged figure - a simulated insect - which has two main components: a gait controller which sequences stepping, and motor programs which control motions of the figure by the application of forces. The simulation is capable of generating gait patterns and walking phenomena observed in nature, and our simulated insect can negotiate planar and uneven terrain in a realistic manner. The motor program techniques should be generally applicable to other control problems.

In this paper we describe the evolution of a whole-hand interface to our virtual-environment graphical system. We present a set of abstractions that can be used to implement device-independent interfaces for hand measurement devices. Some of these abstractions correspond to known logical device abstractions, while others take further advantage of the richness of expression in the human hand. We describe these abstractions in the context of their use in our development of virtual environments.

No abstract available.

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.