The most general way to determine the characteristics of an image is by ray tracing. Ray tracing is a simulation technique that allows to perform computer experiments with a given optical system at a very low cost. Ray tracing simulations are performed to obtain quantitative descriptions of several experimental parameters. It is a common tool in the visible region of the spectrum where several commercial packages are available. These packages are not well suited for the x-ray domain because x-ray optics are used in grazing incidence or strongly off-axis. To perform X-ray optics simulations, we have developed SPOTX a ray tracing software for the X-ray domain. In this paper, we will present several examples concerning optical design simulation in different domains such as synchrotron radiation beamline, x- ray plasma spectroscopy and x-ray laser focusing. We will also present the user friendly graphical interface allowing to quickly define the optical design under consideration.