Glossy reflections may include areas that are less clear (more blurry) than other regions. For instance, an area of reflection that is closer to the object being reflected may appear clearer than a region that is farther from the object. When generating a glossy reflection, the total amount of light...http://www.google.com.hk/patents/US7970237?utm_source=gb-gplus-share專利 US7970237 - Spatially-varying convolutions for rendering glossy reflection effects
