Patent attributes
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 reaching each point on the reflecting surface is calculated according to a spatially-varying convolution kernel of the transparency information for the image being reflected. Ray-tracing, traditionally used to determine a spatially varying convolution, can be very CPU intensive. Instead of using ray-tracing, data structures, such as MIP-maps and summed-area tables, or separable linear filters may be used to compute the spatially-varying convolution. For example, a two-dimensional convolution may be computed as two spatially-varying, separable, linear convolution filters—one computing a horizontal component and the other a vertical component of the final 2D convolution.
