Bidirectional Path Tracing II CS295, Spring 2017 Shuang Zhao - - PowerPoint PPT Presentation

Bidirectional Path Tracing II

CS295, Spring 2017 Shuang Zhao

Computer Science Department University of California, Irvine

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Last Lecture

• Bidirectional path tracing

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Today’s Lecture

• Bidirectional path tracing II

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• Then, connecting each pair of vertices ys, zt

yields a full path sample

• (nL nE) full path samples constructed from one

pair of light and sensor sub-paths

Recap: Building Paths in Batches

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Recap: Path Contribution

• Given a light sub-path with nL vertices and a sensor

sub-path wit nE vertices, each resulting path sample with has contribution: where

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Special Case: s = 0, 1

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No visibility term in Simple path tracing Path tracing with next-event estimation

Special Case: t = 0, 1

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No visibility term in Simple adjoint particle tracing Adjoint particle tracing with next-event estimation

Survival Probability and Albedo

• Assuming

then implies and

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Reflectance albedo

Image Construction

• The value Ij for pixel j equals
• D is the image plane (parameterized using u, v)
• hj is the filter function (e.g., 2D Gaussian)
• I(u, v) is the image function

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D D(u, v)

Example Scene

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Individual Components

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Individual Components (Weighted)

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Next Lecture

• Refraction & Bidirectional Scattering Functions
• Radiative transfer

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