Related Experiment Video
Updated: May 26, 2026
12:26
Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics
Published on: August 27, 2013
On mesh-free valley surface extraction with application to low frequency sound simulation
Harald Obermaier1, Jan Mohring, Eduard Deines
1University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. hobermaier@ucdavis.edu
IEEE Transactions on Visualization and Computer Graphics
|December 14, 2011
Summary
This study introduces a novel meshless method for extracting adaptive valley and ridge surfaces from 3D scalar fields. The approach enhances visualization of complex data, such as acoustic simulations, by revealing sound cancellation regions.
Area of Science:
- Computational geometry
- Scientific visualization
- Acoustics simulation
Background:
- Crease surfaces define extremal structures in 3D scalar fields.
- Existing methods for extracting these surfaces have limitations, particularly with nonmanifold structures and mesh dependencies.
Purpose of the Study:
- To develop a meshless, curvature-adaptive algorithm for extracting nonmanifold valley and ridge surfaces.
- To overcome limitations of prior surface extraction techniques by decoupling point seeding and triangulation.
- To apply the method for visualizing complex-valued scalar fields, specifically in acoustics simulations.
Main Methods:
- A region-growing-based approach for meshless surface extraction.
- Decoupling of point seeding and surface triangulation.
- Curvature adaptive algorithm suitable for arbitrary neighborhood structures.
Main Results:
- Successful extraction of adaptive nonmanifold valley and ridge surfaces.
- Capability to extract valley surface skeletons as connected minimum structures.
- Application to visualize low-frequency acoustics simulations, identifying sound cancellation regions.
Conclusions:
- The proposed meshless method provides an effective way to extract and visualize crease surfaces.
- The approach is robust for complex scalar fields and arbitrary neighborhood structures.
- It offers expressive visualization of wave topology, such as node and antinode structures in acoustics.
Related Concept Videos
01:10Mesh Analysis with Current Sources
Mesh analysis becomes simpler when analyzing circuits with current sources, whether independent or dependent. The presence of current sources reduces the number of equations required for analysis. Two cases illustrate this:
Current Source in One Mesh: The analysis process is straightforward when a current source is found in only one mesh within the circuit. Mesh currents are assigned as usual, with the mesh containing the current source excluded from the analysis. Kirchhoff's voltage law (KVL)...
Current Source in One Mesh: The analysis process is straightforward when a current source is found in only one mesh within the circuit. Mesh currents are assigned as usual, with the mesh containing the current source excluded from the analysis. Kirchhoff's voltage law (KVL)...
01:20Mesh Analysis
Mesh analysis is a valuable method for simplifying circuit analysis using mesh currents as key circuit variables. Unlike nodal analysis, which focuses on determining unknown voltages, mesh analysis applies Kirchhoff's voltage law (KVL) to find unknown currents within a circuit. This method is particularly convenient in reducing the number of simultaneous equations that need to be solved.
A fundamental concept in mesh analysis is the definition of meshes and mesh currents. A mesh is a closed...
A fundamental concept in mesh analysis is the definition of meshes and mesh currents. A mesh is a closed...
01:17Sound as Pressure Waves
Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As a column of the medium is displaced, its successive columns are also displaced. As the successive displacements differ relatively, a pressure difference with the surrounding pressure is created. The gauge pressure varies across the medium.
The pressure fluctuation depends on the difference in displacements between the successive points in the...
The pressure fluctuation depends on the difference in displacements between the successive points in the...
01:18Sinusoidal Sources
Direct current (DC) refers to an electric current that flows in a single direction, maintaining a constant polarity. This is in contrast to alternating current (AC), which periodically changes its direction and magnitude. AC forms the backbone of modern electricity transmission and distribution systems due to its efficient long-distance transmission capabilities.
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
01:28Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
01:27Uniform Depth Channel Flow
Uniform depth channel flow keeps fluid depth consistent along channels such as irrigation canals. In natural channels, such as rivers, approximate uniform flow is often assumed. This condition occurs when the channel’s bottom slope matches the energy slope, balancing potential energy lost from gravity with head loss due to shear stress. This balance prevents depth changes along the channel length, resulting in a steady, uniform flow.Uniform flow in open channels with a constant cross-section...