1: Unit vectors are grouped according to their spherical coordinates. 2: For each group (window), we apply a uniform mapping that relocates subparts to the whole surface of the unit sphere. 3: To compress the vectors, we apply any existing unit vector quantization with an improved precision.

Abstract

We propose a new efficient ray compression method to be used prior to transmission in a distributed Monte Carlo rendering engine. In particular, we introduce a new compression scheme for unorganized unit vector sets (ray directions) which, combined with state-of-the-art positional compression (ray origin), provides a significant gain in precision compared to classical ray quantization techniques. Given a ray set which directions lie in a subset of the Gauss sphere, our key idea consists in mapping it to the surface of the whole unit sphere, for which collaborative compression achieves a high signal-over-noise ratio. As a result, the rendering engine can distribute efficiently massive ray waves over large heterogeneous networks, with potentially low bandwidth. This opens a way toward Monte Carlo rendering in cloud computing, without the need to access specialized hardware such as rendering farms, to harvest the latent horsepower present in public institutions or companies.

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Bibtex

@inproceedings{Rousseau:2017:FLC:3145749.3149436,
 author = {Rousseau, Sylvain and Boubekeur, Tamy},
 title = {Fast Lossy Compression of 3D Unit Vector Sets},
 booktitle = {SIGGRAPH Asia 2017 Technical Briefs},
 series = {SA '17},
 year = {2017},
 isbn = {978-1-4503-5406-6},
 location = {Bangkok, Thailand},
 pages = {23:1--23:4},
 articleno = {23},
 numpages = {4},
 url = {http://doi.acm.org/10.1145/3145749.3149436},
 doi = {10.1145/3145749.3149436},
 acmid = {3149436},
 publisher = {ACM},
 address = {New York, NY, USA},
 keywords = {direction field compression, ray wave compression, unorganized normal vector set compression},
}