Within this paper, we present a novel, straightforward progressive encoding scheme for general triangle soups, which is particularly well-suited for mobile and Web-based environments due to its minimal requirements on the client's hardware and software. Our rapid encoding method uses a hierarchy of quantization to effectively reorder the original primitive data into several nested levels of detail. The resulting stateless buffer can progressively be transferred as-is to the GPU, where clustering is efficiently performed in parallel during rendering. We combine our approach with a crack-free mesh partitioning scheme to obtain a straightforward method for fast streaming and basic view-dependent LOD control.

Despite many advances in mesh compression methods within the past two decades, there is still no consensus about a standardized compact mesh encoding format for 3D Web applications. In order to facilitate the design of a future platform-independent solution, this paper investigates the crucial trade-off between compactness of the compressed representation and decompression time. Our case study evaluates different encoding formats, combined with various transmission bandwidths, using different client devices. Results indicate that good compression rates, and at the same time a fast decompression, can be achieved by exploiting existing browser features and by minimizing the complexity of operations that have to be performed inside the JavaScript layer. Our findings are summarized in concrete recommendations for future standards.

1 Fraunhofer IGD 2 TU Darmstadt (a) 17% triangles, low-resolution texture (b) 86% triangles, low-resolution texture (c) 86% triangles, high-resolution texture (d) 100% triangles, high-resolution texture Figure 1: Streaming of mesh data, progressively encoded with the POP Buffer method, using our proposed SRC container format. We minimize the number of HTTP requests, and at the same time allow for a progressive transmission of geometry and texture information, using interleaved data chunks. Our proposed format is highly flexible, well-aligned with GPU structures, and can easily be integrated into X3D. AbstractA problem that still remains with today's technologies for 3D asset transmission is the lack of progressive streaming of all relevant mesh and texture data, with a minimal number of HTTP requests. Existing solutions, like glTF or X3DOM's geometry formats, either send all data within a single batch, or they introduce an unnecessary large number of requests. Furthermore, there is still no established format for a joined, interleaved transmission of geometry data and texture data.Within this paper, we propose a new container file format, entitled Shape Resource Container (SRC). Our format is optimized for progressive, Web-based transmission of 3D mesh data with a minimum number of HTTP requests. It is highly configurable, and more powerful and flexible than previous formats, as it enables a truly progressive transmission of geometry data, partial sharing of geometry between meshes, direct GPU uploads, and an interleaved transmission of geometry and texture data. We also demonstrate how our new mesh format, as well as a wide range of other mesh formats, can be conveniently embedded in X3D scenes, using a new, minimalistic X3D ExternalGeometry node.