CHORALE (simulated Optronic Acoustic Radar battlefield) is used by the French DGA/DET (Directorate for Evaluation of the French Ministry of Defense) to perform multi-sensors simulations. CHORALE enables the user to create virtual and realistic multi spectral 3D scenes, and generate the physical signal received by a sensor, typically an IR sensor. To evaluate their efficiency in visible and infrared wavelength, simulation tools, that give a good representation of physical phenomena, are used. This article describes the elements used to prepare data (3D database, materials, scenario, ...) for the simulation, and the set of tools (SE-FAST-IR), used in CHORALE for the Real Time simulation in the infrared spectrum. SE-FAST-IR package allows the compilation and visualization of 3D databases for infrared simulations. It enables one to visualize complex and large databases for a wide set of real and pseudo-real time applications. SE-FAST-IR is based on the physical model of the Non Real Time tool of CHORALE workshop. It automatically computes radiance textures, Open GL light source and fog-law parameters for predefined thermal and atmospheric conditions, specified by the user.