1. A method, comprising: determining a directional incidence light source, with respect to a given point of a lighting environment, that is associated with a respective intensity, the determining comprises: generating a mapping of spatial irradiance distribution surrounding a given point of a lighting environment, stitching the mapping into a spherical panorama from a series of images of the lighting environment in a plurality of shooting directions from the given point, determining a salient light source represented in the mapping by executing an importance sampling algorithm, and projecting the determined salient light source from the spherical panorama onto a self-enclosed spherical spatial surface surrounding the given point in the lighting environment to determine the directional incidence light source on the self-enclosed spatial surface, wherein the directional incident light source's direction is towards the given point, and the lighting environment represents an area surrounding a real-world location; utilizing at least one gray value associated with the determined salient light source in the mapping to obtain the respective intensity for the incidence directional light source; generating an image of an object situated at the given point in the lighting environment from a viewing direction by applying a bi-directional reflection distribution function of the object on the respective intensity of the directional incidence light source; and outputting the generated image.