MCGIM-Based Model Streaming for Realtime Progressive Rendering

While most mesh streaming techniques focus on optimizing the transmission order of the polygon data, few approaches have addressed the streaming problems by using geometry images (GIM). In this paper, we present a new approach which firstly partitions a mesh into several surface patches, then converts these patches into multi-chart geometry images (MCGIM). After resampling the MCGIM and normal map atlas are obtained, we hierarchically construct the regular geometry image representation by adopting the quadtree structure. In this way, the encoded nodes can be transmitted in arbitrary order with high transmission flexibility. Also, the rendering quality of the partially transmitted models can be greatly improved by using the normal texture atlas. Meanwhile only the geometry on the silhouette to the current viewpoint are required to be refined and transmitted, therefore the amount of data is minimized for transferring each frame. In particular, our approach also allows users to encode and transmit the mesh data via JPEG2000 technique. Therefore, our mesh streaming method is suitable for transmitting 3D animation models with use of Motion JPEG2000 videos. Experimental results have demonstrated the effectiveness of our approach, which enables one server to stream the MCGIM texture atlas to the clients. Also, the transmitted model can be rendered in a multiresolution manner by GPU acceleration on the client side, due to the regular geometry structure of MCGIM.