Photon Parameterisation for Robust Relaxation Constraints

Ben Spencer and Mark W. Jones

Eurographics 2013 Best Paper Award


This paper presents a novel approach to detecting and preserving fine illumination structure within photon maps. Data derived from each photon's primal trajectory is encoded and used to build a high-dimensional kd-tree. Incorporation of these new parameters allows for precise differentiation between intersecting ray envelopes, thus minimizing detail degradation when combined with photon relaxation. We demonstrate how parameter-aware querying is beneficial in both detecting and removing noise. We also propose a more robust structure descriptor based on principal components analysis that better identifies anisotropic detail at the sub-kernel level. We illustrate the effectiveness of our approach in several example scenes and show significant improvements when rendering complex caustics compared to previous methods.

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B. Spencer and M. W. Jones, Photon Parameterisation for Robust Relaxation Constraints, Computer Graphics Forum, 2013, 32(2pt1), 83-92


	author = {Spencer, B. and Jones, M. W.},
	title = {Photon Parameterisation for Robust Relaxation Constraints},
	journal = {Computer Graphics Forum},
	year = {2013},
	volume = {32},
	pages = {83--92},
	number = {{2pt1}},
	date = {2013-05-07},
	doi = {10.1111/cgf.12028},
	issn = {1467-8659},
	publisher = {Blackwell Publishing Ltd},
	pdf = {}