In principle, the previous version of pvTrace (v2.1.2) 83 could model diverse user-defined LSC architectures through the import of STL files. However, in practice, quantitative modeling to obtain the external photon efficiency was restricted to rectangular LSCs. This is due to the method used to determine the number of rays emitted from the LSC; namely, the program obtains the x-and y-values of each exiting ray and compares these with the dimensions of the box. If the position of the ray matches the box dimensions, then the ray is labeled as an output ray, otherwise it is ignored. The external photon efficiency was then calculated by dividing the number of output rays by the number of incident rays. Unfortunately, this approach cannot be easily extended to geometries such as circles, hexagons, or triangles, which would require complex equations to determine the x-and y-coordinates of the edges. Additionally, pvTrace-v2. To extend the capability of pvTrace to include quantitative modeling of the efficiency for user-defined LSC architectures, in this work we upgrade the output ray counting mechanism.