A system and corresponding method for fast generation of digitally reconstructed radiograph (DRR) images are provided, the system including a processor, an imaging adapter in signal communication with the processor for receiving volumetric data, a preprocessing unit in signal communication with the processor for preprocessing subvolumes into a set of local line integrals, and an online processing unit in signal communication with the processor for online processing global line integrals, each from a set of local line integrals, respectively; and the corresponding method including receiving three-dimensional volumetric data, subdividing the volumetric data into a set of overlapping subvolumes, preprocessing each subvolume into a dense set of local line integrals at several angles and positions, online processing global line integrals, each from a set of local line integrals, respectively, and adding up values of the set of local line integrals for each global line integral to form pixels of the DRR image.