Multi-layer depth peeling via fragment sort

• Published in: 2009 11th IEEE International Conference on Computer-Aided Design and Computer Graphics pp. 452 - 456
• Main Authors: Baoquan Liu, Li-Yi Wei, Ying-Qing Xu, Enhua Wu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.08.2009
• Subjects: Acceleration; Asia; Geometry; Graphics; Hardware; Layout; Rendering (computer graphics); Robustness; Software algorithms; Sorting
• ISBN: 9781424436996; 1424436990
• DOI: 10.1109/CADCG.2009.5246861

We present an accelerated depth peeling algorithm for order-independent transparency rendering on graphics hardware. Unlike traditional depth peeling which only peels one layer of transparent pixels per rendering pass, our algorithm peels multiple layers simultaneously per rendering pass. Our acceleration is achieved via our fragment program which sorts and writes multiple fragment colors and depths via MRT. A notable feature of our algorithm is that it is robust against the unreliable parallel read-after-write behavior in current graphics hardware, guaranteeing correct transparency ordering. For ordinary scenes rendered under RGBA8 color precision, we achieve up to 8x speed-up over conventional depth peeling with current generation graphics hardware. Our algorithm is simple to implement on current GPU without any hardware modification. In addition, it does not require applications to perform any pre-sorting of transparent geometry.