Hardware-compatible vertex compression using quantization and simplification

Abstract

We present a vertex compression technique suitable for efficient decompression on graphics hardware. Given a user-specified number of bits per vertex, we automatically allocate bits to vertex attributes for quantization to maximize quality, guided by an image-space error metric. This allocation accounts for the constraints of graphics hardware by packing the quantized attributes into bins associated with the hardware's vectorized vertex data elements. We show that this general approach is also applicable if the user specifies a total desired model size. We present an algorithm that integrally combines vertex decimation and attribute quantization to produce the best quality model for a user-specified data size. Such models have an appropriate balance between the number of vertices and the number of bits per vertex.Vertex data is transmitted to and optionally stored in video memory in the compressed form. The vertices are decompressed on-the-fly using a vertex program at rendering time. Our algorithms not only work well within the constraints of current graphics hardware but also generalize to a setting where these constraints are relaxed. They apply to models with a wide variety of vertex attributes, providing new tools for optimizing space and bandwidth constraints of interactive graphics applications.

Mesh Geometry Compression for Mobile Graphics

“…Purnomo et al [9] refine the idea of Calver and allocate different numbers of bits for the components of vertex attributes, such as positions, normals, and texture coordinates, to minimize the image-space error. At rendering time, compressed vertex data, which have been packed into fixed 96 bits, 978-1-4244-5176-0/10/$26.00 ©2010 IEEE are transmitted to a programmable vertex shader and restored on-the-fly.…”

“…Compared to [9], in addition to the difference of using local quantization, our technique requires no programmable vertex shader because the decoding operation can be incorporated into the standard geometry transformation, which makes it applicable to a wide range of mobile graphics platforms.…”

On-the-fly appearance quantization on the GPU for 3D broadcasting

“…Some global optimization techniques have been developed (e.g., [Purnomo et al 2005]) in order to provide the optimal quantization code for all the vertex attributes. Intrinsically global, such a method can hardly process streamed data.…”

“…These operators can be emulated using the technique described in [Purnomo et al 2005] which shows how to use fractional and floor functions to simulate bit masks (more details in [Purnomo et al 2005]). In practice, this solution is too slow to be competitive with a CPU solution.…”

Coarse-grained multiresolution structures for mobile exploration of gigantic surface models

“…Hardware-compatible vertex data compression is typically achieved in this context by attribute quantization. Since global position quantization [Calver 2002;Purnomo et al 2005;Lee et al 2009] provides poor rate-distortion performance for large meshes, recent efforts have concentrated on local quantization techniques , which, however, lead to cracks for multiresolution meshes. In CATP, we improve over these local quantization approaches by expressing positions of mesh fragment vertices in the barycentric coordinate system relative to the containing tetrahedron.…”