Advances in Rendering for Physics

The New Journal of Physics is an open-access physics journal well worth perusing. Unlike many online scientific journals, all of the articles can be read without purchasing a subscription. The titles below are linked directly to the papers' pages where pdf versions, HTML versions, and movie files and other materials can all be found. NJoP is an impressive resource. The latest issue, Volume 10, Dec 2008, is focused on Visualization in Physics. A wide ranging series of articles explores the application of computer graphics to scientific study; from simulation, to rendering, to analysis, and presentation. Here, I've picked a few of my favorite articles from the current issue to pique your interest.


Spiral Metamorphosis, collision between the Milky Way and Andromeda galaxies.

Visualizing astrophysical N-body systems
John Dubinski

Abstract. I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic dynamics. These techniques are incorporated into a specialized particle visualization software library called MYRIAD that is designed to render images within large parallel N-body simulations as they run. I present several case studies that explore the application of these methods to animations in star clusters, interacting galaxies and cosmological structure formation.



An SPH data set rendering a galaxy collision

Colliding galaxies, rotating neutron stars and merging black holes—visualizing high dimensional datasets on arbitrary meshes
Werner Benger

Abstract. Visualization of datasets stemming from diverse sources is challenged by the large variety of substantial differences in topology, geometry and nature of the associated data fields. Since there is no standard on how to formulate and treat data for scientific visualization, algorithms are frequently implemented in a highly domain-specific way. Here, we explore the potential of point-wise rendering as a generic way to represent single or multiple fields instantaneously on arbitrary mesh types.




Electron distribution in silicon

Visualizing a silicon quantum computer
Barry C Sanders, Lloyd C L Hollenberg, Darran Edmundson and Andrew Edmundson

Abstract. Quantum computation is a fast-growing, multi-disciplinary research field. The purpose of a quantum computer is to execute quantum algorithms that efficiently solve computational problems intractable within the existing paradigm of `classical' computing built on bits and Boolean gates. While collaboration between computer scientists, physicists, chemists, engineers, mathematicians and others is essential to the project's success, traditional disciplinary boundaries can hinder progress and make communicating the aims of quantum computing and future technologies difficult. We have developed a four minute animation as a tool for representing, understanding and communicating a silicon-based solid-state quantum computer to a variety of audiences, either as a stand-alone animation to be used by expert presenters or embedded into a longer movie as short animated sequences. The paper includes a generally applicable recipe for successful scientific animation production.




A cosmological simulation 10^9 lightyears across

Splotch: visualizing cosmological simulations
K Dolag, M Reinecke, C Gheller and S Imboden

Abstract. We present a light and fast, publicly available, ray-tracer Splotch software tool which supports the effective visualization of cosmological simulations data. We describe the algorithm it relies on, which is designed in order to deal with point-like data, optimizing the ray-tracing calculation by ordering the particles as a function of their `depth', defined as a function of one of the coordinates or other associated parameters. Realistic three-dimensional impressions are reached through a composition of the final colour in each pixel properly calculating emission and absorption of individual volume elements. We describe several scientific as well as public applications realized with Splotch. We emphasize how different datasets and configurations lead to remarkably different results in terms of the images and animations. A few of these results are available online.




Visualization of an MHD current scroll

Flow visualization and field line advection in computational fluid dynamics: application to magnetic fields and turbulent flows
Pablo Mininni, Ed Lee, Alan Norton and John Clyne

Abstract. Accurately interpreting three dimensional (3D) vector quantities output as solutions to high-resolution computational fluid dynamics (CFD) simulations can be an arduous, time-consuming task. Scientific visualization of these fields can be a powerful aid in their understanding. However, numerous pitfalls present themselves ranging from computational performance to the challenge of generating insightful visual representations of the data. In this paper, we briefly survey current practices for visualizing 3D vector fields, placing particular emphasis on those data arising from CFD simulations of turbulence. We describe the capabilities of a vector field visualization system that we have implemented as part of an open source visual data analysis environment. We also describe a novel algorithm we have developed for illustrating the advection of one vector field by a second flow field. We demonstrate these techniques in the exploration of two sets of runs. The first comprises an ideal and a resistive magnetohydrodynamic (MHD) simulation. This set is used to test the validity of the advection scheme. The second corresponds to a simulation of MHD turbulence. We show the formation of structures in the flows, the evolution of magnetic field lines, and how field line advection can be used effectively to track structures therein.




VisTrails workflow showing output of galaxy cluster simulation

Visualization needs and techniques for astrophysical simulations
W Kapferer and T Riser

Abstract. Numerical simulations have evolved continuously towards being an important field in astrophysics, equivalent to theory and observation. Due to the enormous developments in computer sciences, both hardware- and software-architecture, state-of-the-art simulations produce huge amounts of raw data with increasing complexity. In this paper some aspects of problems in the field of visualization in numerical astrophysics in combination with possible solutions are given. Commonly used visualization packages along with a newly developed approach to real-time visualization, incorporating shader programming to uncover the computational power of modern graphics cards, are presented. With these techniques at hand, real-time visualizations help scientists to understand the coherences in the results of their numerical simulations. Furthermore a fundamental problem in data analysis, i.e. coverage of metadata on how a visualization was created, is highlighted.




Accretion disc around a black hole

How computers can help us in creating an intuitive access to relativity
Hanns Ruder, Daniel Weiskopf, Hans-Peter Nollert and Thomas Müller

Abstract. Computers have added many new possibilities to the tool box used for visualizing science in general and relativity in particular. We present some new results from our own work: (2 + 1) dimensional Minkowski diagrams showing two spatial dimensions, extended wormhole visualization, and the illustration of accretion discs by using the approximation via a rigidly rotating disc of dust. We also discuss some related examples from our earlier work, such as interactive and immersive visualization, or the visualization of the warp drive metric.




Image showing large scale structure of galaxies in the universe

Visualization of large scale structure from the Sloan Digital Sky Survey
M U SubbaRao, M A Aragón-Calvo, H W Chen, J M Quashnock, A S Szalay and D G York

Abstract. We will discuss the challenges of visualizing large cosmological datasets. These include observational issues such as the masks and incomplete nature of the survey volume, cosmological issues such as redshift distortions and the difficulty of visualizing datasets that span cosmological epochs, as well as the inherent visualization challenges in presenting dense three-dimensional (3D) datasets. Two case studies will be presented. The first will feature the identification of filamentary structures in the large scale distribution of galaxies. The second case study will feature visualizations of the correlations between quasar absorption line systems and luminous red galaxies. Finally, we will give an overview of our visualization work-flow which features the use of the open-source 3D modeling program Blender.



Several sources of spiral wave structure

Visualization of spiral and scroll waves in simulated and experimental cardiac tissue
E M Cherry and F H Fenton

Abstract. The heart is a nonlinear biological system that can exhibit complex electrical dynamics, complete with period-doubling bifurcations and spiral and scroll waves that can lead to fibrillatory states that compromise the heart's ability to contract and pump blood efficiently. Despite the importance of understanding the range of cardiac dynamics, studying how spiral and scroll waves can initiate, evolve, and be terminated is challenging because of the complicated electrophysiology and anatomy of the heart. Nevertheless, over the last two decades advances in experimental techniques have improved access to experimental data and have made it possible to visualize the electrical state of the heart in more detail than ever before.


Content by Nick Porcino (c) 1990-2011