RayFactor is a primitive based, Monte Carlo Ray Tracer (MC-RT) for the calculation of radiative view factors. This code is out in the wild to serve as an example of MC-RT as well as the use of OpenMP and SSE.
If you require such a program for research purposes rather than just as a code example I would suggest instead taking a look at RayFactorCL. It is OpenCL based and if you are equipped with a half decent GPU it will be many times faster.
At the terminal cd into the root project directory and then build using gcc :
g++ -fopenmp -msse -msse2 -msse3 -mssse3 -msse4 -msse4.1 -msse4.2 -O3 -Wall -o build/rayfactor src/*.cpp
Note: RayFactor uses OpenMP and SSE (hence the flags).
On the Mac g++ is aliased to Apple's LLVM which does not support OpenMP, so if you haven't done so already go ahead and install homebrew and then use it to install gcc. You can make sure you are using the correct version of g++ by typing g++ -v at the terminal.