Abstract
Geometry compression is the compression of the 3D geometric data that provides a computer graphics system with the scene description necessary to render images. Geometric data is quite large and, therefore, needs effective compression methods to decrease the transmission and storage bit requirements. A large amount of research has focused on static geometry compression, but only limited research has addressed animated geometry compression, the compression of temporal sequences of geometry data. In this paper, we propose an octree-based motion representation method that can be applied to compress animated geometric data. In our approach, 3D animated sequences can be represented with a compression factor of over 100, with slight losses in animation quality. We focus on compressing vertex positions for all the frames. In our approach we only need to use two consecutive frames to generate a small set of motion vectors that represent the motion from the previous frame to the current frame. The motion vectors are used to predict the vertex positions for each frame except the first frame. The process generates a hierarchical octree motion representation for each frame. Quantization and an adaptive arithmetic coder are used to achieve further data reduction. The simple and efficient decompression of this approach makes it suitable for real time applications.