Streaming data to efficiently render complex 3D scenes in presence of global illumination is still a challenging task. In this paper, we introduce a new data structure based on a 3D grid of irradiance vectors to store the indirect illumination appearing on complex and detailed objects: the Irradiance Vector Grid (IVG). This representation is independent of the geometric complexity and is suitable for quantization to different quantization schemes. Moreover, its streaming over network involves only a small overhead compared to detailed geometry, and can be achieved independently of the geometry. Furthermore, it can be efficiently rendered using modern graphics hardware. We demonstrate our new data structure in a new remote 3D visualization system, that integrates indirect lighting streaming and progressive transmission of the geometry, and * {pacanows | raynaud | granier| reuter | schlick}@labri.fr † poulin@iro.umontreal.ca study the impact of different strategies on data transfer.

Figure 1: A client/server 3D broadcasting application, with on-demand quantization to reduce bandwidth. The on-demand quantization workload is delayed to the GPU on the server side. AbstractThis paper presents an improved client-server system that increases the availability of remote 3D data. In order to reduce the required bandwidth, the data related to the appearance (color and normal) involved in the rendering of meshes and point clouds is quantized on-the-fly during the transmission to the final client, without reducing the geometric complexity. Our new quantization technique for the appearance that can be implemented on the GPU, strongly reduces the CPU load on the server-side and the transmission time is largely decreased.