Real-time shading with filtered importance sampling

We propose an analysis of numerical integration based on sampling theory, whereby the integration error caused by aliasing is suppressed by pre-filtering. We derive a pre-filter for evaluating the illumination integral yielding filtered importance sampling, a simple GPU-based rendering algorithm for image-based lighting. Furthermore, we extend the algorithm with real-time visibility computation. Free from any pre-computation, the algorithm supports fully dynamic scenes and, above all, is simple to implement