Sub-Pixel Anti-Aliasing Via Triangle-Based Geometry Reconstruction

Abstract

Anti-aliasing has recently been employed as a post-processing step to adapt to the deferred shading technique in real-time applications. Some of these existing algorithms store supersampling geometric information as geometric buffer (G-buffer) to detect and alleviate sub-pixel-level aliasing artifacts. However, the anti-aliasing filter based on sampled sub-pixel geometries only may introduce unfaithful shading information to the sub-pixel color in uniform-geometry regions, and large G-buffer will increase memory storage and fetch overheads. In this paper, we present a new Triangle-based Geometry Anti-Aliasing (TGAA) algorithm, to address these problems. The coverage triangle of each screen pixel is accessed, and then, the coverage information between the triangle and neighboring sub-pixels is stored in a screen-resolution bitmask, which allows the geometric information to be stored and accessed in an inexpensive manner. Using triangle-based geometry, TGAA can exclude irrelevant neighboring shading samples and achieve faithful anti-aliasing filtering. In addition, a morphological method of estimating the geometric edges in high-frequency geometry is incorporated into the TGAA's anti-aliasing filter to complement the algorithm. The implementation results demonstrate that the algorithm is efficient and scalable for generating high-quality anti-aliased images.