ANALYSIS OF THE HIGH TEMPERATURE SUPERCONDUCTING MAGNETIC PENETRATION DEPTH USING THE BLOCH NMR EQUATIONS

The Bloch-NMR diagnostic tool has shown good efficiency not only analyzing biological and physiological properties of living tissues. The Bloch-NMR has been used in this research work to analyze the penetration depths of superconducting material and thin film. From the two well known London penetration depths, various relationships between the penetration depth and other superconducting quantities were derived (which are theoretically and experimentally valid). The major objective is to explore new ways penetration depths can be measured. A new superconducting quantity (penetration velocity) was discussed - whose relationship with other superconducting quantities were worked out for further researc

Real Time Rendering of Atmospheric Scattering and Volumetric Shadows

International audienceReal time rendering of atmospheric light scattering is one of the most difficult lighting effect to achieve in computer graphics. This paper presents a new real time method which renders these effects including volumetric shadows, which provides a great performance improvement over previous methods. Using an analytical expression of the light transport equation we are able to render directly the contribution of the participating medium on any surface. The rendering of shadow planes, sorted with a spatial coherence technique, and in the same philosophy than the shadow volume algorithm will add the volumetric shadows. Realistic images can be produced in real time for usual graphic scenes and at a high level framerate for complex scenes, allowing animation of lights, objects or even participating media. The method proposed in this paper use neither precomputation depending on light positions, nor texture memory

Metropolis light transport for participating media

We show how Metropolis light transport can be extended both in the underlying theoretical framework and the algorithmic implementation to incorporate volumetric scattering. We present a generalization of the path integral formulation that handles anisotropic scattering in non-homogeneous media. Based on this framework we introduce a new mutation strategy that is specifically designed for participating media. Our algorithm includes effects such as volume caustics and multiple volume scattering, is not restricted to certain classes of geometry and scattering models and has minimal memory requirements. Furthermore, it is unbiased and robust, in the sense that it produces satisfactory results for a wide range of input scenes and lighting situations within acceptable time bound

Rendering of light shaft and shadow for indoor environments enhancing technique

The ray marching methods have become the most attractive method to provide realism in rendering the effects of light scattering in the participating media of numerous applications. This has attracted significant attention from the scientific community. Up-sampling of ray marching methods is suitable to evaluate light scattering effects such as volumetric shadows and light shafts for rendering realistic scenes, but suffers of cost a lot for rendering. Therefore, some encouraging outcomes have been achieved by using down-sampling of ray marching approach to accelerate rendered scenes. However, these methods are inherently prone to artifacts, aliasing and incorrect boundaries due to the reduced number of sample points along view rays. This study proposed a new enhancing technique to render light shafts and shadows taking into consideration the integration light shafts, volumetric shadows, and shadows for indoor environments. This research has three major phases that cover species of the effects addressed in this thesis. The first phase includes the soft volumetric shadows creation technique called Soft Bilateral Filtering Volumetric Shadows (SoftBiF-VS). The soft shadow was created using a new algorithm called Soft Bilateral Filtering Shadow (SBFS). This technique was started by developing an algorithm called Imperfect Multi-View Soft Shadows (IMVSSs) based on down-sampling multiple point lights (DMPLs) and multiple depth maps, which are processed by using bilateral filtering to obtain soft shadows. Then, down-sampling light scattering model was used with (SBFS) to create volumetric shadows, which was improved using cross-bilateral filter to get soft volumetric shadows. In the second phase, soft light shaft was generated using a new technique called Realistic Real-Time Soft Bilateral Filtering Light Shafts (realTiSoftLS). This technique computed the light shaft depending on down-sampling volumetric light model and depth test, and was interpolated by bilateral filtering to gain soft light shafts. Finally, an enhancing technique for integrating all of these effects that represent the third phase of this research was achieved. The performance of the new enhanced technique was evaluated quantitatively and qualitatively a measured using standard dataset. Results from the experiment showed that 63% of the participants gave strong positive responses to this technique of improving realism. From the quantitative evaluation, the results revealed that the technique has dramatically outpaced the stateof- the-art techniques with a speed of 74 fps in improving the performance for indoor environments

Interactive Rendering of Scattering and Refraction Effects in Heterogeneous Media

In this dissertation we investigate the problem of interactive and real-time visualization of single scattering, multiple scattering and refraction effects in heterogeneous volumes. Our proposed solutions span a variety of use scenarios: from a very fast yet physically-based approximation to a physically accurate simulation of microscopic light transmission. We add to the state of the art by introducing a novel precomputation and sampling strategy, a system for efficiently parallelizing the computation of different volumetric effects, and a new and fast version of the Discrete Ordinates Method. Finally, we also present a collateral work on real-time 3D acquisition devices

Computation of Global Illumination in a Participating Medium by Monte Carlo Simulation S.N.Pattanaik and S.P.Mudur

This paper discusses techniques for the computation of global illumination in environments with participating medium using a Monte Carlo simulation of the particle model of light. E cient algorithms and data structures for tracking the particles inside the volume have been developed. The necessary equation for computing the illumination along any given direction has been derived for rendering a scene with participating medium. A major issue in any Monte Carlo simulation is the uncertainty in the-nal simulation results. Various steps of the algorithm have been analysed to identify major sources of uncertainty. To reduce the uncertainty, suitable modi cations to the simulation algorithm have been suggested using variance reduction methods of forced collision, absorption suppression and particle divergence. Some sample scenes showing the results of applying these methods are also included