LucidRaster: GPU Software Rasterizer for Exact Order-Independent Transparency

TL;DR

LucidRaster is a GPU-based software rasterizer that enables efficient, exact order-independent transparency rendering for complex scenes, outperforming many existing algorithms in speed and accuracy.

Contribution

The paper introduces LucidRaster, a novel GPU software rasterizer with a two-stage sorting and sample accumulation method for precise transparency rendering.

Findings

Faster than high-quality OIT approximations

Only about 3x slower than hardware alpha blending

Efficient for scenes with high triangle density or depth complexity

Abstract

Transparency rendering is problematic and can be considered an open problem in real-time graphics. There are many different algorithms currently available, but handling complex scenes and achieving accurate, glitch-free results is still costly. This paper describes LucidRaster: a software rasterizer running on a GPU which allows for efficient exact rendering of complex transparent scenes. It uses a new two-stage sorting technique and sample accumulation method. On average it's faster than high-quality OIT approximations and only about 3x slower than hardware alpha blending. It can be very efficient especially when rendering scenes with high triangle density or high depth complexity.