Modified cosine-quadratic reflectance model

Abstract

In the article, a new light reflectance model is proposed.The model is based on the modified cosine-quadratic bidirectional reflectance distribution function. The concept of bidirectional reflectance distribution function is analyzed.The disadvantagesof existing physically accurateand empirical bidirectional reflectance distribution functions, including classical cosine-quadratic function, are discussed. The necessity of new empiricaldistributive functions development is justified. The comparison of double integrals of hemispherical reflectivity of reference Blinn function and classical cosine-quadratic function is provided. Based on the comparison, the new expression of cosine-quadratic distributive function calculation is obtained.The proposed expression makes it possibleto significantly increase the accuracy of glare epicentrereproduction and is intended for use in highly productive three-dimensional rendering systems.