ABSTRACT
In this chapter we describe the volumetric transparency method for rendering transparent objects that departs from classic alpha blending. Instead, it builds per-pixel lists of surface fragments and evaluates illumination analytically between neighboring pairs. This new approach allows object transparency and color to depend on material thickness, and transparent objects are allowed to intersect. Thus, the method is geared at the most prevalent application of transparency: particle system rendering, where it avoids all popping and clipping artifacts characteristic of alpha-blended billboard clouds. We also show how texturing, shadows, or light shafts can be added.
