Uniform cubemap for graphics system

Abstract

The aim of this project is to discuss the partition of the spherical function by using the mirror reflection effect. The mirror reflection effect is to demonstrate the effectiveness of presenting the spherical function by uniform cubemap. Cubemap is a standard method to represent a spherical function in computer graphics. Cubemapping is a cost effective method for mirror reflection effect which is popular use in graphics system due to its simple computation [1]. There are linear samples on the cubemap; however, the main problem is that the distribution of samples on the unit sphere is non-uniform. The distribution of samples at the face centre is much sparser than the surface corner of the sphere, which means the surface centre of the sphere presenting less environment details than that of the corners of the sphere. It causes aliasing problem which particularly presents near the edge of 3D object. Therefore, it is suggested that the uniform cubemap is used to improve the uniformity of the area mapped on the sphere. Insert of sampling linearly on the cubemap, non-linearly samples are used on the uniform cubemap to form a linearly distributed samples on the unit sphere. Uniform cubemap can help to present details of the environment on the reflective object with equal weighting sampling comparing to cubemap. The reduction of aliasing effect on the reflective object can be achieved.