Production rendering changed radically in last few years. With ever increasing computing power, it is now possible to use raytracing and physically based lighting and shading in production. The tools evolved (surfaces are now using normalized brdfs, lighting is using sampled arealights) and rendering is becoming more and more a sampling problem. Even in real-time rendering, we begin to see the use of such algorithms (like sampled ambient occlusion). Monte Carlo integration is the most common method of solving the rendering equation. Although the basic version does not have a remarkable convergence behaviour, numerous techniques have been added to the toolbox of the shader writer to make it practical.