Pipelined Sort-last Rendering: Scalability, Performance and Beyond

We present in this paper a theoretical and practical performance analysis of pipelined sort-last rendering for both polygonal and volume rendering. Theoretical peak performance and scalability are studied, exhibiting maximum attainable framerates of 19 fps (volume rendering with back-to-front alpha blending) and 11 fps (polygonal ren-dering with Z-buffer compositing) for a 1280 × 1024 display on a Gigabit Ethernet cluster. We show that our implementation of pipelined sort-last rendering on a 17-node PC cluster can nearly sustain these theoretical fig-ures. We finally propose possible enhancements that would allow to go beyond the maximum theoretical limits. This paper clearly shows the potential of pipelined sort-last rendering for real-time visualization of very large models on standard PC clusters