Photon Mapping Reference Material The slides have used/adapted - PowerPoint PPT Presentation

Photon Mapping

Reference Material The slides have used/adapted material from the following references: Slides on Photon Mapping by Jan Kautz (web4.cs.ucl.ac.uk/teaching/4074/archive/.../04_ photon _ maps .pdf) Slides on Photon Mapping by Bill Clark (http://penguin.ewu.edu/cscd570/2011/PDFNotes/PhotonMapping.pdf)

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Photon Mapping Ray Tracing • Cast a ray from the eye through each pixel • Trace secondary rays (light, reflection, refraction)

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Photon Mapping The Rendering Equation (Kajiya '86) x'' x x' # L x ( ' x '' ) E x ( ' x '' ) f ( , ' , '' ) ( x x x L x x V x x G x x dx ' ) ( , ' ) ( , ' ) " = " + " r x • L(x'->x'') is the total radiance from x' • f is the BRDF

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Photon Mapping Caustic Reflection (<=#%&#7&(&>(.4=<& (<*%+&

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Photon Mapping Introduction

Photon Mapping Introduction • Store photons – position + light power + incoming direction

Photon Mapping Introduction • Efficiently store photons for fast access • Use hierarchical spatial structure (kd-tree)

Photon Mapping Introduction • Cast primary rays • For secondary rays – reconstruct irradiance using k closest photons • Combine with irradiance caching and other techniques

Photon Mapping Introduction Photon Mapping - Caustics • Special photon map for specular reflection and refraction Glass sphere

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