Lightweight WebSIM Rendering Framework Based on Cloud-Baking

Current cloud rendering systems are expensive in terms of data storage, rendering computation, and networking transmission. In this paper, we propose a novel framework for lightweight and realistic WebSIM rendering based on cloud baking. Different from the existing cloud rendering systems that render full-frame image sequences, we propose that global illumination (GI) maps are baked occasionally at the server side. Our proposed framework consists of three key stages. First, the GI maps are re-baked only when the users change the WebSIM scene or the lighting. Then, after re-baking, these GI maps with indirect illumination are encoded and transferred to the client's web browsers using H.264. Finally, these GI maps are decoded and blended to produce rather realistic illuminating effects with WebGL direct illuminations. Compared with cloud rendering techniques, our system is lightweight, as it consumes much fewer resources at the cloud server in terms of both data and rendering. It provides a highly efficient, high-quality, and low-cost solution to WebSIM online interactive rendering. A prototype has been implemented, and we showed that it is able to achieve real-time rendering performance and satisfactory visual effects on web browsers, similar to popular offline rendering engines.