1. A system to support scattered spherical harmonic (SH) approximation, comprising: a sampling module operable to select an initial subset of sampling points related to an object to be rendered from a substantially uniform distribution of sampling points, the initial subset of sampling points selected based at least partly on density variations of a volume, the initial subset of sampling points varying in density, further wherein a first subset of the initial subset of sampling points is selected at least partly to be inside a surface of the object and a second subset of the initial subset of sampling points is selected at least partly to be over the surface of the object such that a combination of the first subset and the second subset substantially suppresses oscillations from a fitting polynomial associated with the sampling module; a pre-computing module operable to: compute, at each of the initial subset of sampling points, a set of SH coefficients for each of one or more functions used for rendering the object, wherein SH coefficients are not computed at the non-selected sampling points; and approximate, based on the set of SH coefficients at the initial subset of sampling points, a set of SH coefficients for each of the one or more functions at any other point; and a real-time rendering module operable to render global illumination effect of the object at run time based on the one or more functions.