Sorted pipeline image composition

The core advantage of sort last rendering is the theoretical nearly linear scalability in the number of rendering nodes, which makes it very attractive for very large polygonal and volumetric models. The disadvantage of sort last rendering is that a final image composition step is necessary in which a huge amount of data has to be transferred between the rendering nodes. Even with gigabit or faster networks the image composition introduces an overhead that makes it impractical to use sort last parallel rendering for interactive applications on large clusters. This paper describes the Sorted Pipeline Composition algorithm that reduces the amount of data that needs to be transferred by an order of magnitude and results in a frame rate that is at least twice as high as the widely used binary swap image composition algorithm.