Multi-layered Framebuffer Condensation: The l-buffer Concept

Abstract

In this paper we present a method that can be used with algorithms requiring the presence of multiple data elements at the last step of z-buffer based rasterization pipeline. The work presented here-in gives a ground for solutions to problems of order independent transparency; semi-transparent light occluders; non-uniform, light scattering media and visualization of voxel based data. It can also enable the interactive graphics researchers to adapt some algorithms previously only found in off-line solutions. Its general form also allows it to work seamlessly with hardware-accelerated multi-sampling techniques. The contributions of this work include:

• general description of the data structures used in sparse to dense buffer condensation process;

• mapping of the general structures into actual hardware resources;

• rendering process for multi-layered sparse framebuffer;

• condensing the sparse buffer into dense fragment list buffer;

• mapping the list buffer into displayable framebuffer.