It is ultimately based on the Eikonal equation as a short-wavelength approximation to the scalar Helmholtz equation. In piecewise homogeneous media, it results in a repetitive calculation of intersections of lines (i.e., rays) with the surfaces separating the volumes of homogeneous refractive index (i.e., the optical elements) as well as evaluation of Snell’s law. This basic principle involves no mutual dependence of the individual rays and implies a linear dependency of the computational effort and the number of rays involved in the problem. This mutual independence of the light rays bears a huge potential for parallelization of the computational load. Therefore Institute for Technical Optics is developing a GPU-accelerated ray tracer called MacroSim, that is based on nVidias acceleration engine OptiX. It traces in double precision and exploits the massively parallel architecture of modern graphics cards. It has been used to solve computationally expensive problems such as Monte Carlo based stray light analysis of complex optical systems. Furthermore the source code of the tracer is published (see https://bitbucket.org/itom/macrosim/) under a GPL license and is open for application specific customizations.
- F. Mauch, M. Gronle, W. Lyda, W. Osten, Open-source graphics processing unit–accelerated ray tracer for optical simulation, Opt. Eng. 52(5), 053004 (May 09, 2013). http://dx.doi.org/10.1117/12.889175
- F. Mauch, D. Fleischle, W. Lyda, W. Osten, T. Krug, R. Häring, Combining rigorous diffraction calculation and GPU accelerated nonsequential raytracing for high precision simulation of a linear grating spectrometer, Proc. SPIE 8083, Modeling Aspects in Optical Metrology III, 80830F (May 23, 2011). http://dx.doi.org/10.1117/12.889175