Efficient Rendering of Glossy Materials by Interpolating Prefiltered Environment Maps based on Primary Normals

We propose a method to improve the speed of the rendering of glossy surfaces including anisotropy reflection, using prefiltering. The key idea is to prefilter an environment light map for multiple primary normals. Furthermore, we propose an interpolation method to smoothly connect the boundaries generated by switching multiple prefiltered environment maps. As a result, we are able to render objects with glossy surface more accurately even in real-time.