The need for high-fidelity modelling of radiation detectors to perform reliable detector performance optimization using Monte Carlo simulations requires to accurately simulate the light transport in the scintillator and the light collection by the photodetector. Within the Imaging Physics Modeling and Simulation Tools project of the Roncali Lab, we implement our well validated model of crystal reflectance computed from 3D crystal surface measurement in an open source standalone application to allow researchers to generate fully customized crystal reflectance look-up-tables (LUTs) to be used in optical Monte Carlo simulation TheLUTDavisModel standalone is a user-friendly tool for researchers to generate LUTs in their specific scintillator-coupling-reflector configuration and to use them in GATE optical Monte Carlo simulation. Given a surface sample, the algorithm computes the angular distribution of reflectance and transmittance and the angular distribution of reflected and transmitted rays as a function of incidence angle (from 0° to 90°). The LUT computation includes the reflector, the coupling medium, and the photon tracking between the two interfaces. This algorithm allows accurate modeling of photon interactions with crystal surfaces with or without a reflector. The Davis LUT model has been validated against experimental data and added in GATE from v8.0