We have developed a simulation tool for a Wolter I telescope subject to deformations. The aim is to understand
and predict the behavior of Simbol-X and other future missions (NuSTAR, Astro-H, IXO, ...). Our code, based
on Monte-Carlo ray-tracing, computes the full photon trajectories up to the detector plane, along with the
deformations. The degradation of the imaging system is corrected using metrology. This tool allows to perform
many analyzes in order to optimize the configuration of any of these telescopes.