  The development of a 3-dimensional simulation for Cherenkov photon emissions
in Extensive Air Showers (EAS) is reported in this paper. CORSIKA is the most
widely used Monte-Carlo generator for the description of EAS, but it is not
recommended to calculate Cherenkov light emissions for EAS at ultra high
energies due to the enormous amount of data storage and running time required.
The presented BinTheSky is a framework to simulate the Cherenkov light
emissions using the spatial information produced by Monte-Carlo generators. The
light is emitted in the shower, propagated and attenuated to the ground. The
framework enables one to calculate the light spatial, timing and directional
distributions at the ground or at a given altitude, whereas the usual approach
of Ultra High Energy Cosmic Ray experiments relies on the simulation of the
longitudinal shower development and on parametrizations of the transverse
shower distributions.
