Byounghyun Yoo, Don Brutzman and Soonhung Han, International Symposium on Remote Sensing 2009, Busan, Korea, 28-30 October 2009.

Abstract:

Digital Earth is being re-evaluated and there are weakness and limitations in geobrowsers despite of its successful widespread adoption. Especially the interoperability of virtual globes, neutrality of digital earth model, and openness are tasks to be solved for putting forward the vision of the Digital Earth. This paper presents an open standard-based approach for digital representations of the Earth that enable a person to explore and interact with the vast amounts of natural and cultural information gathered about the Earth. The proposed approach is utilizing the Extensible 3D Graphics (X3D) Geospatial Component in order to guarantee interoperability of information interchange and prevent audience being bounded by single digital earth system that is statedly mass-market oriented such as Google Earth. The intent here is to provide a mechanism for producers to present and publish geospatial information and for users to navigate and search for it. This work facilitates users to build their own specially designed Digital Earth depending on their distinct set of needs for information visualization about our planet.

Keywords: Digital Earth, Virtual Globe, Extensible 3D Graphics (X3D) Geospatial Component, X3D Earth, GIS, Spatial Data Infrastructures, Interactive Simulation Interoperability.

Byounghyun Yoo and Don Brutzman, The 14th International Conference on 3D Web Technology (Web3D 2009 Symposium), Darmstadt, Germany, pp.159-166, 16-17 June 2009.

Abstract:

Broad needs for digital models of real environments such as 3D terrain or cyber cities are increasing. Many applications related to modeling and simulation require virtual environments constructed from real-world geospatial information in order to guarantee relevance and accuracy in the simulation. The most fundamental data for building virtual environments, terrain elevation and orthogonal imagery, is typically acquired using optical sensors mounted on satellites or airplanes. Providing interoperable and reusable digital models in 3D is important for promoting practical applications of high-resolution airborne imagery.

This paper presents research results regarding virtual-environment representations of geospatial information, especially for 3D shape and appearance of virtual terrain. It describes a framework for constructing real-time 3D models of large terrain based on highresolution satellite imagery. This approach is also suitable for underwater bathymetry. The Extensible 3D Graphics (X3D) Geospatial Component standard is applied to produce X3D Earth models with global scope. Efficient rendering, network retrieval and data caching/removal must all be optimized simultaneously, across servers, networks and clients, in order to accomplish these goals properly. Details of this standard-based approach for providing an infrastructure for real-time 3D simulation merging high-resolution geometry and imagery are also presented. This work facilitates open interchange and interoperability across diverse simulation systems and is independently usable by governments, industry, scientists and the general public.

Keywords: Extensible 3D Graphics (X3D) Geospatial Component, X3D Earth, satellite imagery, interactive simulation interoperability

DOI: 10.1145/1559764.1559789

Byounghyun Yoo, Don Brutzman, Soonhung Han, International Symposium on Remote Sensing, Daejeon Korea, 29-31 October 2008.

Abstract:

The needs for digital models of real environment such as 3D terrain or cyber city model are increasing. Most of applications related with modeling and simulation require virtual environment constructed from geospatial information of real world in order to guarantee reliability and accuracy of the simulation. The most fundamental data for building virtual environment, terrain elevation and orthogonal imagery is acquired from optical sensor of satellite or airplane. Providing interoperable and reusable digital model is important to promote practical application of high-resolution satellite imagery. This paper presents the new research regarding representation of geospatial information, especially for 3D shape and appearance of virtual terrain, and describe framework for constructing real-time 3D model of large terrain based on high-resolution satellite imagery. It provides infrastructure of 3D simulation with geographical context. Details of standard-based approach for providing infrastructure of real-time 3D simulation using high-resolution satellite imagery are also presented. This work would facilitate interchange and interoperability across diverse systems and be usable by governments, industry scientists and general public.

Keywords: satellite image, interactive simulation, interoperability, X3D Earth, application infrastructure, standard

Byounghyun Yoo, Soonhung Han, International Conference on Computer Graphics and Interactive Techniques, ACM SIGGRAPH 2006 Sketches, Boston Massachusetts, 30 July - 3 August 2006.

Abstracts:

We present a technique to manage the silhouette of objects protruding from the surface without polygonal modeling of the object shape. The technique can represent the correct silhouette and the parallax of protruding shapes by solving the overflow problem that frequently occurs in image-based displacement mapping approaches.

DOI: 10.1145/1179849.1180078

Byounghyun Yoo, Moohyun Cha, Soonhung Han, International Conference on Cyberworlds, Singapore, pp.237-244, 23-25 November 2005.

Abstract:

Virtual reality simulators have been developed as tools for the transfer of knowledge and education. Concurrently, the demand for exhibition systems of science education and cultural experiences has also increased. Existing VR (virtual reality) simulators, which are based on the calculation of dynamics equations, cannot easily be adapted to changes in simulation content. In order to transfer knowledge and maintain interest through educational applications, an experiential system that has multi-sensory effects as well as motion effects is needed. The authors proposed a method for motion generation that is tailored to riding systems and multi-sensory VR effects. In this study, both sense of motion, which is generated from movement of the viewpoint of the visual image, and motion effects, which are prepared in advance, are blended to realize motion simulation by the proposed method. Motion effects can easily be added by interaction between the user and the riding system. Various sensory cues are also implemented to the riding system.

DOI: 10.1109/CW.2005.5

Byounghyun Yoo, Soonhung Han, Korea-China Joint Conference on Geometric and Visual Computing, Busan Korea, pp.161-170, 24-26 August 2005.

Abstract:

This paper describes a representation for the real-time mapping displacement of buildings onto the polygon model of base terrain ingeo-spatial information. Geo-spatial information used for modelingthe virtual environment of flight simulation is similar to thedisplacement map. The buildings are represented as height maps,leading to a technique with very low memory requirements and notinvolving any changes of the model's original geometry (i.e., novertices are created or displaced). In this approach, thedisplacement of buildings is mapped toward the protruding direction.As a result, the base of texture which represents the ground intopography is correctly mapped onto base polygon without anydistortion. Since the displacement of buildings is applied as theheight field, instead of depth field as in previous approaches, theprotruding shape of buildings can be correctly represented. Thisapproach can exhibit the correct occlusions between buildings andground due to parallax and correct self-occlusion. The approach canbe used to consistently add representations of buildings to originalgeometric models of underlying terrain.

Keywords: aerial photograph, digital map, displacement mapping, geo-visualization, image-based rendering

Dong-Soo Kwon, Gi-Hun Yang, Chong-Won Lee, Jae-Cheol Shin, Youngjin Park, Byungbo Jung, Doo Yong Lee, Kyungno Lee, Soon-Hung Han, Byoung-Hyun Yoo, Kwang-Yun Wohn, and Jung-Hyun Ahn, IEEE International Conference on Robotics & Automation, Seoul Korea, Vol. 3, pp.2313-2318, 21-26 May 2001.

Abstract:

This paper presents key technologies and system integration issues of the KAIST interactive bicycle simulator. The rider on the bicycle feels the motion and has the visual experience as if he/she is riding in the campus of the Korea Advanced Institute of Science and Technology. The simulator consists of a bicycle, a Stewart platform, a Magneto-Rheological handle and a pedal resistance system to generate motion feelings; the real-time visual simulator and the projection system; the sub-controllers and the integrating control network.