1. A surface material rendering system comprising: a user input part for receiving user inputs; a material information preprocessor for converting surface material information inputted from the user input part in a form of B-spline volumes; a sampling information preprocessor for producing sampling information in proportion to the converted surface material information; and a surface material renderer for rendering surface materials based on the converted surface material information and the sampling information, wherein the sampling information preprocessor generates a cumulative density function table from raw data for derivation of an inverse function, takes samples of important incident angles using a random number generator, and performs B-spline volumes fitting using raw sampling data to store the sampling information, wherein the sampling information preprocessor includes: a cumulative density function table calculating part for generating the cumulative density function table from raw data to derive the inverse function; a raw sampling data calculating part for taking samples of important incident angles using the random number generator; a B-spline volume fitting part for performing the B-spline volumes fitting using the raw sampling data; and a B-spline integrating part for mathematically integrating B-spline volumes to derive marginal density functions.