1. An image processing apparatus comprising: a first calculator to generate a shadow map with respect to each of plural sampling virtual light sources that are provided on a three dimensional (3D) model, at a first viewpoint; a selector to select, from the plurality of sampling virtual light sources, at least one seed virtual light source for image rendering, based on the at least one seed virtual light source being determined to be exposed at a second viewpoint respectively using the shadow maps of the sampling virtual light sources; and a second calculator to add a respective plurality of super sampling virtual light sources to the 3D model around the selected at least one seed virtual light source for exposure at the second viewpoint, and to generate a shadow map with respect to each of the added super sampling virtual light sources for the image rendering.