10:45 AM - 12:15 PM
[MGI31-P04] Development of Voxel Model Viewer for Geological/Geotechnical Properties using WebGL
Keywords:Voxel, WebGL, Three-dimensional model, Urban areas
Geological Survey of Japan (GSJ) conducts a project to create three-dimensional (3D) urban geological maps to a depth of several tens of meters using borehole data obtained from drilling surveys for stratigraphic research and public construction work (Nakazawa et al., 2018; Naya et al., 2021), and to make the 3D maps visible on the Web in understandable style (Nonogaki and Nakazawa, 2022; URL1). To date, the 3D geological maps are provided as 3D data called “surface-based model”, consists of several geological boundary surfaces. The surface-based models are effective for representing the detailed shape of subsurface geological layers but are not suitable for visualize lateral and vertical changes in lithofacies and physical properties such as N-values within layers because it does not have attribute information between the geological boundary surfaces. The problem regarding the surface-based geological model is a major obstacle to promote the use of geological information in urban areas created by GSJ.
To solve this problem, GSJ is currently creating voxel models that represent the distribution of such geological/geotechnical properties within geological layers, as well as developing a viewer that visualizes voxel model on web browser at good speed using Web Graphic Library (WebGL). In this voxel model viewer, the WebGL is controlled by the three.js, one of the major JavaScript libraries for 3D computer graphics. The viewer has interactive functions for switching type of voxel model, for showing only cells of specific geological/geotechnical properties, for adjusting the vertical exaggeration ratio of the 3D view, and for setting the light source position and background color. The available type of voxel model is rock types, rock hardness, and data density. In addition, the viewer enables to show vertical cross section images along arbitrary lines as well as horizon cross section images at arbitrary heights. The position of cross section images can be interactively adjusted by operating slide bar. These functions are useful for easily understanding the shallow subsurface geological structure in urban areas. In this presentation, we will talk about an outline of the voxel model viewers, focusing on its functions.
References:
Naya et al. (2018) Explanatory Text of the Urban Geological Map of the northern area of Chiba Prefecture. Geological Survey of Japan, AIST, 55p.
Naya et al. (2021) Explanatory Text of the Urban Geological Map of Central Tokyo (Special Wards Area). Geological Survey of Japan, AIST, 82p.
Nonogaki, S. and Nakazawa, T. (2022) Development of WebGL-Based Three-Dimensional Geological Model Viewer. JpGU Meeting 2022.
URL1: Urban Geological Map, https://gbank.gsj.jp/urbangeol/
To solve this problem, GSJ is currently creating voxel models that represent the distribution of such geological/geotechnical properties within geological layers, as well as developing a viewer that visualizes voxel model on web browser at good speed using Web Graphic Library (WebGL). In this voxel model viewer, the WebGL is controlled by the three.js, one of the major JavaScript libraries for 3D computer graphics. The viewer has interactive functions for switching type of voxel model, for showing only cells of specific geological/geotechnical properties, for adjusting the vertical exaggeration ratio of the 3D view, and for setting the light source position and background color. The available type of voxel model is rock types, rock hardness, and data density. In addition, the viewer enables to show vertical cross section images along arbitrary lines as well as horizon cross section images at arbitrary heights. The position of cross section images can be interactively adjusted by operating slide bar. These functions are useful for easily understanding the shallow subsurface geological structure in urban areas. In this presentation, we will talk about an outline of the voxel model viewers, focusing on its functions.
References:
Naya et al. (2018) Explanatory Text of the Urban Geological Map of the northern area of Chiba Prefecture. Geological Survey of Japan, AIST, 55p.
Naya et al. (2021) Explanatory Text of the Urban Geological Map of Central Tokyo (Special Wards Area). Geological Survey of Japan, AIST, 82p.
Nonogaki, S. and Nakazawa, T. (2022) Development of WebGL-Based Three-Dimensional Geological Model Viewer. JpGU Meeting 2022.
URL1: Urban Geological Map, https://gbank.gsj.jp/urbangeol/