Seok Yoon Jung

Interpolator data compression for MPEG-4 animation

Interpolator representation in key-frame animation is now the most popular method for computer animation. The interpolator data consist of key and key value pairs, where a key is a time stamp and a key value is the corresponding value to the key. In this paper, we propose a set of new technologies to compress the interpolator data. The performance of the proposed technique is compared with the existing MPEG-4 generic compression tool. Throughout the core experiments in MPEG-4, the proposed technique showed its superiority over the existing tool, becoming a part of MPEG-4 standard within the Animation Framework eXtension framework.

Animation data compression in MPEG-4: interpolators

In this paper, we propose new technologies to compress the interpolator nodes in VRML/MPEG-4 BIFS (binary format for scene). Interpolators are used to animate the 3D objects in a VRML/MPEG-4 BIFS scene. For interactive applications with quite a few animated 3D synthetic objects, two components are dominant in the amount of data to represent the animation: 3D object and its animation. In the current MPEG-4, 3D model coding (3DMC) yields a high compression ratio with reasonable quality for the 3D object, while predictive MFField coding (PMFC) yields a moderate compression ratio with reasonable quality for the animation data. The proposed techniques are to provide a high compression on animation data and have been adopted to MPEG-4 system amendment 4 (AFX/MUW).

HART: A Hybrid Architecture for Ray Tracing Animated Scenes

We present a hybrid architecture, inspired by asynchronous BVH construction [1], for ray tracing animated scenes. Our hybrid architecture utilizes heterogeneous hardware resources: dedicated ray-tracing hardware for BVH updates and ray traversal and a CPU for BVH reconstruction. We also present a traversal scheme using a primitives axis-aligned bounding box (PrimAABB). This scheme reduces ray-primitive intersection tests by reusing existing BVH traversal units and the primAABB data for tree updates; it enables the use of shallow trees to reduce tree build times, tree sizes, and bus bandwidth requirements. Furthermore, we present a cache scheme that exploits consecutive memory access by reusing data in an L1 cache block. We perform cycle-accurate simulations to verify our architecture, and the simulation results indicate that the proposed architecture can achieve real-time Whitted ray tracing animated scenes at 1,920 × 1,200 resolution. This result comes from our high-performance hardware architecture and minimized resource requirements for tree updates.

Fast tile-binning method by detecting 1D-overlapped primitives

Mobile 3D graphics use tile-based rendering algorithm in order to lower power consumption. For rendering tile by tile in the tile-based rendering, tile-binning process is inevitable and has to store the results of geometry processing into scene buffer, which causes memory access severely. Several methods were proposed to reduce memory bandwidth for tile-binning process. However, these memory-bandwidth reduction methods require more computations. Hsieh et al. attempted to eliminate edges in order to decrease the number of overlap test. Their method could only eliminate 0.02% of edges because the edges parallel to the axes can be eliminated. In this study, we propose a simple method to reduce the number of the overlap test by detecting 1D-tile overlapped primitives, which are overlapped with only one-dimensional tiles while keeping low memory bandwidth.