Primitive Processing and Advanced Shading Architecture for Embedded Space

Abstract

This paper presents a new graphics architecture enabling contentrich applications for the embedded space by extending hardware architecture in two main areas - geometry processing and configurable per-fragment shading. Our first contribution combines vertex cache and a programmable geometry engine that handles both fixed and variable size geometrical primitives completely on-chip. It enables subdivision surface tessellation, silhouette rendering and other geometry processing algorithms to be implemented in one pass and without external memory access. Our second contribution is in configurable per-fragment shading that is mainly a dot product + lookup table machine being versatile enough to realize Cook-Torrance shading, Schlick anisotropy model and others. Memory storage and memory bandwidth are reduced in proposed architecture as both compact geometry and material descriptions are possible, enabling complex shapes and sophisticated shading models in embedded space. The architecture has complete HDL and ASIC implementations and was demonstrated during the ESEC 2008 exhibition in Japan. Exposing all the features of our architecture via OpenGL ES 1.X and 2.0 API enabled extended OpenGL ES engines from Rightware Oy to run on our ASIC implementations.