ABSTRACT
Deferred shading is a popular technique in real-time rendering. In contrast to a traditional rendering pipeline, deferred shading is split into two phases. First, the geometry is sampled and stored in the geometry buffer, which serves as input for the second phase where the shading is computed. Thereby, the complexity for shading is decoupled from the geometric complexity, and furthermore advanced geometry-aware screen-space techniques may be employed. However, deferred shading does not play well with multi-sample antialiasing. Multi-sample antialiasing samples the visibility of a primitive at several subpixel positions, however the shading is only evaluated once inside a pixel per primitive. Deferred shading samples the geometric attributes, and the shading is deferred into a second phase where the correspondence between primitives and visibility samples is lost, which makes it hard to avoid redundant shading. Furthermore, the geometry buffer can become prohibitively large in case of high screen resolutions and high visibility sampling because each sample needs to store all attributes.
