Yuna Kang

Editing 3D models on smart devices

This study proposes a 3D CAD system available on smart devices, which are now a part of everyday life and which are widely applied in various domains, such as education and robot industry. If an engineer has a new idea while traveling or on the move, or in the case of collaboration between more than two engineers, this 3D CAD system allows modeling to be performed in a rapid and simple manner on a smart device. This 3D CAD system uses the common multi-touch gestures associated with smart devices to keep the modeling operations simple and easy for users. However, it is difficult to input the precise geometric information to generate 3D CAD models by such gestures. It is also impractical to provide a full set of modeling operations on a smart device due to hardware limitations. For this reason, the system excludes several complicated modeling operations. This work provides a scheme to regenerate a parametric 3D model on a PC-based CAD system via a macro-parametrics approach by transferring the 3D model created on a smart device in an editable form to a PC-based CAD system. If fine editing is needed, the user can perform additional work on a PC after reconstruction. Through the developed system, it is possible to produce a 3D editable model swiftly and simply in the smart device environment, allowing for reduced design time while also facilitating collaboration. This paper discusses the first-ever system design of a 3D CAD system on a smart device, the selection of the modeling operations, the assignment of gestures to these operations, and use of operation modes. This is followed by an introduction of the implementation methods, and finally a demonstration of case studies using a prototype system with examples.

Automatic 3D City Modeling Using a Digital Map and Panoramic Images from a Mobile Mapping System

Three-dimensional city models are becoming a valuable resource because of their close geospatial, geometrical, and visual relationship with the physical world. However, ground-oriented applications in virtual reality, 3D navigation, and civil engineering require a novel modeling approach, because the existing large-scale 3D city modeling methods do not provide rich visual information at ground level. This paper proposes a new framework for generating 3D city models that satisfy both the visual and the physical requirements for ground-oriented virtual reality applications. To ensure its usability, the framework must be cost-effective and allow for automated creation. To achieve these goals, we leverage a mobile mapping system that automatically gathers high-resolution images and supplements sensor information such as the position and direction of the captured images. To resolve problems stemming from sensor noise and occlusions, we develop a fusion technique to incorporate digital map data. This paper describes the major processes of the overall framework and the proposed techniques for each step and presents experimental results from a comparison with an existing 3D city model.

Improvement of smartphone interface using an AR marker

Smartphones have come into wide use recently, and are increasingly popular not only among young people, but also among middle-aged people as well. Most smartphones use a capacitive full touch screen, where touch commands are made by the users fingers, unlike PDAs in the past that used touch pens. In this case, a significant portion of the smartphones screen is blocked by the finger and thus it is impossible to see the screen around the finger touching the screen. Furthermore, precise control for small buttons such as a QWERTY keyboard is difficult. To resolve these problems, this paper proposes a method of using simple AR markers to improve the interface of smartphones. A sticker-form marker is attached to the users fingernails and placed in front of the smartphone camera. A camera image of the marker is then analyzed to determine the position and the orientation of the marker, and its position is used as the position of the mouse cursor. This method can enable click, double-click, and drag-and-drop used in PCs as well as touch, slide, and long-touch-input in smartphones. Through this research, more precise and simple smartphone inputs can be realized.

Collaborative Visualization of a Warfare Simulation Using a Commercial Game Engine

The requirement about reusable 3D visualization tool was continuously raised in various industries. Especially in the defense modeling and simulation field, there are abundant researches about reusable and interoperable visualization system, since it has a critical role to the efficient decision making by offering diverse validation and analyzing process. Also to facilitate the effectiveness, many current operating systems are applying VRVirtual Reality and ARAugmented Reality technologies aggressively. In this background, we conducted the research about the design for the collaborative visualization environment for the warfare simulation through commercial game engine. We define the requirements by analyzing advantages and disadvantages of existing tools or engines like SIMDIS or Vega, and propose the methods how to utilize the functionalities of commercial game engine to satisfy the requirements. The implemented prototype offers collaborative visualization environment inside the CAVE environment, which is the facility for immersive virtual environment, by cooperating with handheld devices.

A Study on the Photo-realistic 3D City Modeling Using the Omnidirectional Image and Digital Maps

3D city model, which consisted of the 3D building models and their geospatial position and orientation, is becoming a valuable resource in virtual reality, navigation systems, civil engineering, etc. The purpose of this research is to propose the new framework to generate the 3D city model that satisfies visual and physical requirements in ground oriented simulation system. At the same time, the framework should meet the demand of the automatic creation and cost-effectiveness, which facilitates the usability of the proposed approach. To do that, I suggest the framework that leverages the mobile mapping system which automatically gathers high resolution images and supplement sensor information like position and direction of the image. And to resolve the problem from the sensor noise and a large number of the occlusions, the fusion of digital map data will be used. This paper describes the overall framework with major process and the recommended or demanded techniques for each processing step.

Development of a Converter for Visualizing SEDRIS

The need for reusing synthetic environment data that are employed in the field of modeling and simulation has recently been rising. SEDRIS (Synthetic Environment Data Representation & Interchange Specification) is a standard to exchange synthetic environment data, and is the specification utilized in various military simulations of the Pentagon for representing and exchanging 3D data. SEDRIS represents environmental areas based on a data model; it can represent wind speed, wind directions, weather changes, the information of buildings, as well as terrain data. In some situations, however, the synthetic environment data stored in SEDRIS format should be converted to various visualization formats. First, because SEDRIS is a form of a super-set, it is necessary to verify whether large scale SEDRIS files are stored successfully through visualization. Second, the synthetic environment data should be visualized in some visualization programs for the simulation results to provide an immersive and realistic sense. In this study, we have developed converters for converting SEDRIS data to various visualization formats and visualized the converted results.

Development of v-DMU Based on e-Science Using COVISE and SAGE

Virtual digital mock-up (v-DMU) refers to all of the activities in the design, analysis, and visualization of the product in a 3D virtual environment that lead to a lower cost and a higher quality. In the early days, designers exchanged CAD files directly in collaborations. Recently, DMU systems have been used for relatively effective designs that generally support distributed and collaborative design capability by sharing the design data via the Internet. However, a range of problems can arise in such a case. In the case of large-scale products such as aircrafts or ships, the data size can be on a scale so large that it requires large amount of space on the workstation and requires considerable time for exchanges. Moreover, security problems often occur in the process of data exchanges. For a company and a nation, this can be crucial. The immersive visualization of product design data is becoming more important in collaborative design. As a solution to these issues, this paper proposes a new approach using the technology of the remote visualization of CAD data. This involves the streaming of rendered graphics using COVISE and SAGE. This paper also introduces the implementation of v-DMU based on e-Science by remote visualization.