Spherical Harmonic Exponentials for Efficient Glossy Reflections

We propose a high‐performance and compact method for computing glossy specular reflections. Commonly‐used prefiltered environment maps have large storage requirements and high error due to constrained treatment of view‐dependence. We propose a factorized spherical harmonic exponential representation that exploits new observations of the benefits of log‐space reconstruction for reflectance. Our method is compact, properly accounts for view‐dependent reflections, and is more accurate than the state‐of‐the‐industry solutions. We achieve higher quality results with an order of magnitude less memory, all with efficient and alias‐free reconstruction of glossy reflections from environment lights and continuously‐varying material roughness.