Visualization of 3D Density Current Movement by Implicit Surfaces Modeling with Volumetric Fog Treatment
Date Issued
2008
Date
2008
Author(s)
Liu, Chien-Wei
Abstract
The most important benefit of computer graphics in the field of computational fluid dynamics is to visualize the data results from numerical computations. However, an image created by computer graphic techniques is not so realistic and some techniques can not be easily applied due to lack of mesh profile or node relationship. The purpose of this study is to apply the implicit surfaces modeling method and the volumetric-foggy rendering technique for visualizing computed data, and describing the movement of three-dimensional density current. The obtained images and animations are helpful for those who have no hydraulic background for understanding the phenomena of fluid flow.n this study, parameters of implicit surfaces modeling method are estimated, and a regressed relation between influence radius and ideal threshold for Metaballs scalar function is also established. Four cases of applications are performed including dam-break flow, two-phase flow, density current in the flume, and the density current in the Shihmen Reservoir. The results suggest that the implicit surfaces modeling method can generate continuous surfaces describing free surface of fluid and density current. Furthermore, the smoothness of implicit surfaces and computational efficiency can be adjusted through parameters of scalar function. Volumetric fog can exhibit the object with fuzzy boundary such as cloud, fog or muddy water. Blending noise texture with three-dimensional scene can improve object more realistic, especially interface between density current and clear water. The fuzzy effect of volumetric fog display is different from the polygon model in current visualization technique.
Subjects
Scientific visualization
Realistic image
Density current
Implicit surfaces modeling
Metaballs modeling
Volumetric fog
Noise texture
Type
thesis
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