(A) mobile 3D display processor with a bandwidth-efficient subdivider

Abstract

This paper presents a mobile 3D display processor with a subdivider, which can visualize smooth rendering effects on a mobile 3D display. Today mobile devices support high visual quality similar to desktop PCs. To support true-realism on handhelds, this work supports both the 3D display and the modern 3D graphics technique such as a subdivision function within mobile restrictions. In order to run 3D display contents with subdivision surfaces on mobile environment, we must solve two problems. The one is the frame rate of 3D display processing, and the other is the insufficient bandwidth of mobile devices. To enjoy interactive 3D display contents in real-time, system must support high frame rate more than 60fps. In 3D display process, the main performance bottleneck is division operation. I develop a fast modulus operator and transform a depth-to-disparity converting equation from a division to a multiplication, which completely eliminate division operations during 3D display process. As a result, the processor increases 3D image synthesis rate up to 116fps which is 17 times faster than a previous mobile 3D display platform. Handhelds have a quite limited memory architecture compared with desktop PCs. In mobile devices, many multimedia IPs share the same memory and bus with a limited bit-width. This memory architecture significantly under-utilizes the high computing power of modern multi-media processors such as GPUs, so bandwidth becomes a main performance bottleneck. This research focuses on saving bandwidth requirement, which translates into significant improvement in terms of off-chip memory access latency and energy. In order to reduce the bandwidth, this work basically minimizes the working set of subdivision process and 3D display process. The proposed subdivider is running based on depth-first scheme. The subdivider fetches a single target face and its one-ring neighborhood information from a base mesh and then subdivides the target face until its s...