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mmp / pbrt-v2

Source code for the version of pbrt described in the second edition of "Physically Based Rendering"
http://pbrt.org
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About screen clamping in irradiance cache. #36

Closed 2H0U closed 6 years ago

2H0U commented 9 years ago

Since the pixel spacing is computed from dpdx and dpdy of differential geometry, if the camera ray hits many mirror before reaching a diffuse surface, the spacing may become very large. Because the minimum contribution range is " minSamplePixelSpacing * pixelSpacing " the cache point will cover a very large area. And if it's position is close to the camera, the artifact appears.

mmp commented 6 years ago

Acknowledged that this is an issue with the current implementation. However, closing as "will not fix", since pbrt-v3 doesn't support irradiance caching. Thanks for reporting this, though!