Eddy Kuo

Shape reconstruction from contours using isotopic deformation

Abstract A method for shape reconstruction from contours using isotopic deformation is presented. The proposed method considers the case where one contour encloses the other contour when they are projected in a common plane, as is the case for terrain contour maps. Unlike many other methods which generate piecewise linear interpolation, the proposed method smoothly interpolates between two contours located in parallel planes. The algorithm runs in O(nk+n log n) time, where n is the total number of vertices in two contours and k is an integer variable less than n which indicates how convoluted the contours are (the larger, the more convoluted). The running time of the algorithm is shown to be worst-case optimal for the class of task defined. The reconstructed shape is free of self-intersections and it can incorporate given feature correspondences. The method is extended to handle bifurcations and is shown to cope easily with some cases which are problematic for some other algorithms. The method proposed is suitable for terrain modeling, since reconstructed shapes generated by the method do not have overhangs. Experimental results are included to illustrate the feasibility of the approach.

Three-dimensional visualization of microstructures

This case study describes a technique for the three-dimensional analysis of the internal microscopic structure (microstructure) of materials. This technique consists of incrementally polishing through a thin layer (approximately 0.2 /spl mu/m) of material, chemically etching the polished surface, applying reference marks, and performing optical or scanning electron microscopy on selected areas. The series of images are then processed employing AVS and other visualization software to obtain a 3D reconstruction of the material. We describe how we applied this technique to an alloy steel to study the morphology, connectivity, and distribution of cementite precipitates formed during thermal processing. The results showed microstructural features not previously identified with traditional 2D techniques.

A computational steering system for studying microwave interactions with missile bodies

The paper describes a computer modeling and simulation system that supports computational steering, which is an effort to make the typical simulation workflow more efficient. Our system provides an interface that allows scientists to perform all of the steps in the simulation process in parallel and online. It uses a standard network flow visualization package, which has been extended to display graphical output in an immersive virtual environment such as a CAVE. Our system allows scientists to interactively manipulate simulation parameters and observe the results. It also supports inverse steering, where the user specifies the desired simulation result, and the system searches for the simulation parameters that achieve this result. Taken together, these capabilities allow scientists to more efficiently and effectively understand model behavior, as well as to search through simulation parameter space. The paper is also a case study of applying our system to the problem of simulating microwave interactions with missile bodies. Because these interactions are difficult to study experimentally, and have important effects on missile electronics, there is a strong desire to develop and validate simulation models of this phenomena.

Goal-orientated computational steering

Computational steering is a newly evolving paradigm for working with simulation models. It entails integration of model execution, observation and input data manipulation carried out concurrently in pursuit of rapid insight and goal achievement. Keys to effective computational steering include advanced visualization, high performance processing and intuitive user control. The Naval Research Laboratory (NRL) has been integrating facilities in its Virtual Reality Lab and High Performance Computing Center for application of computational steering to study effects of electromagnetic wave interactions using the HASP (High Accuracy Scattering and Propagation) modeling technique developed at NRL. We are also investigating automated inverse steering which involves incorporation of global optimization techniques to assist the user with tuning of parameter values to produce desired behaviors in complex models.

A Computational Steering System for Studying Microwave Interactions with Space-Borne Bodies

This paper describes a computer modeling and simulation systemthat supports computational steering, which is an effort to makethe typical simulation workflow more efficient. Our system providesan interface that allows scientists to perform all of the stepsin the simulation process in parallel and online. It uses a standardnetwork flow visualization package, which has been extended todisplay graphical output in an immersive virtual environment suchas a CAVE. Our system allows scientists to interactively manipulatesimulation parameters and observe the results. It also supportsinverse steering, where the user specifies the desired simulationresult, and the system searches for the simulation parameters thatachieve this result. Taken together, these capabilities allow scientiststo more efficiently and effectively understand model behavior,as well as to search through simulation parameter space.This paper is also a case study of applying our system to theproblem of simulating microwave interactions with missile bodies.Because these interactions are difficult to study experimentally, andhave important effects on missile electronics, there is a strong desireto develop and validate simulation models of this phenomena.

GROTTO visualization for decision support

In this paper we describe the GROTTO visualization projects being carried out at the Naval Research Laboratory. GROTTO is a CAVE-like system, that is, a surround-screen, surround- sound, immersive virtual reality device. We have explored the GROTTO visualization in a variety of scientific areas including oceanography, meteorology, chemistry, biochemistry, computational fluid dynamics and space sciences. Research has emphasized the applications of GROTTO visualization for military, land and sea-based command and control. Examples include the visualization of ocean current models for the simulation and stud of mine drifting and, inside our computational steering project, the effects of electro-magnetic radiation on missile defense satellites. We discuss plans to apply this technology to decision support applications involving the deployment of autonomous vehicles into contaminated battlefield environments, fire fighter control and hostage rescue operations.

VR scientific visualization in the GROTTO

We describe the efforts being carried out at the Naval Research Laboratory (NRL) towards VR scientific visualization. We are exploring scientific visualization in an immersive virtual environment: the NRLs CAVE/sup TM/-like device known as GROTTO (Graphical room for observation, Training and Tactical Orientation). We describe the AVS GROTTO viewer, a VR interface to the AVS visualization system. The AVS GROTTO viewer has been used by a number of scientists in current, ongoing research projects within NRL.

VR visualization of large fluid-flow data sets

In this paper we describe the efforts being carried out by the Laboratory of Computational Physics, the Scientific Visualization Laboratory and the Virtual Reality Laboratory of the Naval Research Laboratory towards visualization of large data sets. We have concentrated on fluid flow hydrodynamics data sets. We describe the fully threaded tree structure developed at NRL to tackle the problem of massive parallel calculations using local mesh refinement methods. This structure was implemented with the IBM Data Explorer environment, allowing a multiresolution visualization system that inherits the properties of the tree structure in a natural way. We also describe the visualization of these data sets in a virtual environment.

Using Virtual Reality to Visualize Scientific, Engineering, and Medical Data

In this paper we briefly discuss the state of the art of Virtual Reality as applied to visualization of scientific and technical data sets. We describe the technologies and software for the creation of Virtual Environments. We also give an overview of some of the more significant and successful Virtual Reality applications in the fields of medicine, engineering, chemistry and computational fluid dynamics.

VR scientific visualization in an immersive room

This paper describes the efforts being carried out at the NRL towards VR Scientific Visualization. We are exploring scientific visualization in an immersive virtual environment: the NRLs CAVE-like device known as the GROTTO. Our main effort has been towards the development of software that eases the transition between desktop visualization and VR visualization. It has been our intention to develop visualization tools that can be applied in a wide range of scientific areas without spending excessive time in software development. The advantages of such software are clear. The scientists do not have to be expert programmers, nor need they make a large investment of time to visualize scientific information in a Virtual Environment. As a result of this effort, we were able to port a considerable number of applications to the GROTTO in a short period of time. These projects cover a wide range of scientific areas and include chemistry, fluid dynamics, space physics and materials sciences. We describe the major technical hurdles we have addressed for interactive visualization of real data sets for real users. Finally we comment on the advantages that immersive systems like the GROTTO offer to the scientific community.