Fast oriented line integral convolution for vector field visualization via the Internet (original) (raw)

Animating flow fields: rendering of oriented line integral convolution

Proceedings. Computer Animation '97 (Cat. No.97TB100120), 1997

Line Integral Convolution (LIC) is a common approach for the visualization of 2 0 vector fields. It is well suited for visualizing the direction of a flow field, but it gives no information about the orientation of the underlying vectors. We introduce Oriented Line Integral Convolution (OLIC), where direction as well as orientation are encoded within the resulting image. This is achieved b y using a sparse input texture and a ramp like (anisotropic) convolution kernel. This method can be used for animations, whe,reby the computation of so called pixel traces fastens the calculation process. In the result section various OLICs illustrating simple and real-world vector fields are shown.

Visualizing vector fields: the thick oriented stream-line algorithm (TOSL)

Computers & Graphics, 2001

The visualization of dense vector fields has important applications for scientific purposes. Beyond the standard methods, such as arrows and particle tracing, texture-based methods are able to show almost all the details of a field. This paper presents the Thick Oriented Stream-Line (TOSL) algorithm, which can show direction, orientation and local flow speed even for dense vector fields by simulating the convolution process. A practical comparison of the performances of TOSL vs. other visualizations algorithms (LIC and fastLIC) shows that the proposed algorithm can provide output textures faster than the other considered techniques. r

High-quality animation of 2d steady vector fields

IEEE Transactions on Visualization and Computer Graphics, 2004

Simulators for dynamic systems are now widely used in various application areas and raise the need for effective and accurate flow visualization techniques. Animation allows us to depict direction, orientation, and velocity of a vector field accurately. This paper extends a former proposal for a new approach to produce perfectly cyclic and variable-speed animations for 2D steady vector fields (see [1] and [2]). A complete animation of an arbitrary number of frames is encoded in a single image. The animation can be played using the color table animation technique, which is very effective even on low-end workstations. A cyclic set of textures can be produced as well and then encoded in a common animation format or used for texture mapping on 3D objects. As compared to other approaches, the method presented in this paper produces smoother animations and is more effective, both in memory requirements to store the animation, and in computation time.

Texture Particles: Interactive Visualization of Volumetric Vector Fields

2001

This paper introduces a new approach to the visualization of volumetric vector fields with an adaptive distribution of animated particles that show properties of the underlying steady flow. The shape of the particles illustrates the direction of the vector field in a natural way. The particles are transported along streamlines and their velocity reflects the local magnitude of the vector field. Further physical quantities of the underlying flow can be mapped to the emissive color, the transparency and the length of the particles. A major effort has been made to achieve interactive frame rates for the animation of a large number of particles while minimizing the error of the computed streamlines. There are three main advantages of the new method. Firstly, the animation of the particles diminishes the inherent occlusion problem of volumetric vector field visualization, as the human eye can trace an animated particle even if it is highly occluded. The second advantage is the variable resolution of the visualization method. More particles are distributed in regions of interest. We present a method to automatically adjust the resolution to features of the vector field. Finally, our method is scalable to the computational and rasterization power of the visualization system by simply adjusting the number of visualized particles.

Imaging vector fields using line integral convolution

1993

Imaging vector fields has applications in science, art, image processing and special effects. An effective new approach is to use linear and curvilinear filtering techniques to locally blur textures along a vector field. This approach builds on several previous texture generation and filtering techniques . It is, however, unique because it is local, one-dimensional and independent of any predefined geometry or texture. The technique is general and capable of imaging arbitrary two-and three-dimensional vector fields. The local one-dimensional nature of the algorithm lends itself to highly parallel and efficient implementations. Furthermore, the curvilinear filter is capable of rendering detail on very intricate vector fields. Combining this technique with other rendering and image processing techniques -like periodic motion filtering -results in richly informative and striking images. The technique can also produce novel special effects.

High-Quality and Interactive Animations of 3D Time-Varying Vector Fields

IEEE Transactions on Visualization and Computer Graphics, 2000

In this paper, we present an interactive texturebased method for visualizing three-dimensional unsteady vector fields. The visualization method uses a sparse and global representation of the flow, such that it does not suffer from the same perceptual issues as is the case for visualizing dense representations. The animation is made by injecting a collection of particles evenly distributed throughout the physical domain. These particles are then tracked along their path lines. At each time step, these particles are used as seed points to generate field lines using any vector field such as the velocity field or vorticity field. In this way, the animation shows the advection of particles while each frame in the animation shows the instantaneous vector field. In order to maintain a coherent particle density and to avoid clustering as time passes, we have developed a novel particle advection strategy which produces evenly-spaced field lines at each time step. To improve rendering performance, we decouple the rendering stage from the preceding stages of the visualization method. This allows interactive exploration of multiple fields simultaneously, which sets the stage for a more complete analysis of the flow field. The final display is rendered using texture-based direct volume rendering.

Interactive Visualization of Volumetric Vector Fields Using Texture Based Particles

2002

Directional enhancement in texture-based vector field visualization

Proceedings of the 4th …, 2006

The use of textures provides a rich and diverse set of possibilities for the visualization of flow data. In this paper, we present methods designed to produce oriented and controlled textures that accurately reflect the complex patterns that occur in vector field visualizations. We offer new insights based on the specification and classification of neighborhood models for synthesizing a texture that accurately depicts a vector field. Secondly, we introduce a computationally efficient method of texture mapping streamlines utilizing outlining textures to depict flow orientation. efficient method of texture mapping streamlines utilizing outlining textures to depict flow orientation.

Flow Charts: Visualization of Vector Fields on Arbitrary Surfaces

IEEE Transactions on Visualization and Computer Graphics, 2000

We introduce a novel flow visualization method called Flow Charts, which uses a texture atlas approach for the visualization of flows defined over curved surfaces. In this scheme, the surface and its associated flow are segmented into overlapping patches, which are then parameterized and packed in the texture domain. This scheme allows accurate particle advection across multiple charts in the texture domain, providing a flexible framework that supports various flow visualization techniques. The use of surface parameterization enables flow visualization techniques requiring the global view of the surface over long time spans, such as Unsteady Flow LIC (UFLIC), particle-based Unsteady Flow Advection Convolution (UFAC), or dye advection. It also prevents visual artifacts normally associated with view-dependent methods. Represented as textures, Flow Charts can be naturally integrated into hardware accelerated flow visualization techniques for interactive performance.

Flow Visualization Based on A Derived Rotation Field

Electronic Imaging, 2016

We identify and investigate the Φ field-a derived flow attribute field whose value at a given spatial location is determined by the integral curve initiated at the point. Specifically, we integrate the angle difference between the velocity vectors at two consecutive points along the integral curve to get the Φ field value. Important properties of the Φ field and its gradient magnitude |∇Φ| field are studied. In particular, we show that the patterns in the derived Φ field are generally aligned with the flow direction based on an inequality property. In addition, we compare the Φ field with some other attribute fields and discuss its relation with a number of flow features, such as LCS and cusp-like seeding structures. Furthermore, we introduce a unified framework for the computation of the Φ field and its gradient field, ∇Φ, and employ the Φ field and |∇Φ| field to a number of flow visualization and exploration tasks, including integral curve filtering, seeds generation and flow domain segmentation. We show that these tasks can be conducted more efficiently based on the information encoded in the Φ field.

Fast oriented line integral convolution for vector field visualization via the Internet (original) (raw)

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