  Detection of scintillation light can play several important roles in LArTPCs.
Increased collection efficiency could result in the improvement of time,
energy, and position resolution. The SBND collaboration is developing detailed
MC simulations to study the performance of different types of light systems in
the LArSoft framework. Due to the vast number of photons typically produced in
neutrino physics events, a full optical simulation becomes extremely hard to
run on reasonable time scales. I will describe how the SBND simulation tackles
these problems and its current status for two of the light detection systems
considered by SBND: (i) a traditional TPB-coated PMT based system and (ii) a
system based on TPB-coated reflector foils to increase collection efficiency
without increasing the number of photodetectors.
