GPU-based four-dimensional general-relativistic ray tracing

Abstract

This paper presents a new general-relativistic ray tracer that enables image synthesis on an interactive basis by exploiting the performance of graphics processing units (GPUs). The application is capable of visualizing the distortion of the stellar background as well as trajectories of moving astronomical objects orbiting a compact mass. Its source code includes metric definitions for the Schwarzschild and Kerr spacetimes that can be easily extended to other metric definitions, relying on its object-oriented design. The basic functionality features a scene description interface based on the scripting language Lua, real-time image output, and the ability to edit almost every parameter at runtime. The ray tracing code itself is implemented for parallel execution on the GPU using NVidia’s Compute Unified Device Architecture (CUDA), which leads to performance improvement of an order of magnitude compared to a single CPU and makes the application competitive with small CPU cluster architectures.Program summaryProgram title: GpuRay4DCatalog identifier: AEMV_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMV_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 73649No. of bytes in distributed program, including test data, etc.: 1334251Distribution format: tar.gzProgramming language: C++, CUDA.Computer: Linux platforms with a NVidia CUDA enabled GPU (Compute Capability 1.3 or higher), C++ compiler, NVCC (The CUDA Compiler Driver).Operating system: Linux.RAM: 2 GBClassification: 1.5.External routines: OpenGL Utility Toolkit development files, NVidia CUDAToolkit 3.2, Lua5.2Nature of problem: Ray tracing in four-dimensional Lorentzian spacetimes.Solution method: Numerical integration of light rays, GPU-based parallel programming using CUDA, 3D-Rendering via OpenGL.Running time: Problem dependent, several seconds up to hours.