Diffuse Direct Pass Anti Aliasing color spill #48147

New Issue

Riccardo Giovanetti · 2016-04-14T15:46:07+02:00

2016-04-14 15:46:07 +02:00

System Information
Windows 7 Pro 64bit w/SP1, 8GB RAM, GTX360M (1GB VRAM)

Blender Version
Broken: 2.77a 64bit (Hash: abf6f08) official stable release (ZIP version)
Worked: (optional)

Short description of error
When rendering with Cycles on CPU there is a visible color spill in the anti aliased areas of the Diffuse Direct pass (looking closely it might affect also the Diffuse Indirect pass). Shouldn't the Diffuse Direct pass be only black and white?

Exact steps for others to reproduce the error

As per the attached sample .blend file, running Cycles on CPU (I cannot render on GPU) produces a color spill in the Anti-Aliased areas of the image visible in the Diffuse Direct (and perhaps in the Diffuse Indirect) pass, where the entire image should be black and white instead.

color-spill-test.blend

**System Information** Windows 7 Pro 64bit w/SP1, 8GB RAM, GTX360M (1GB VRAM) **Blender Version** Broken: 2.77a 64bit (Hash: abf6f08) official stable release (ZIP version) Worked: (optional) **Short description of error** When rendering with Cycles on CPU there is a visible color spill in the anti aliased areas of the Diffuse Direct pass (looking closely it might affect also the Diffuse Indirect pass). Shouldn't the Diffuse Direct pass be only black and white? **Exact steps for others to reproduce the error** As per the attached sample .blend file, running Cycles on CPU (I cannot render on GPU) produces a color spill in the Anti-Aliased areas of the image visible in the Diffuse Direct (and perhaps in the Diffuse Indirect) pass, where the entire image should be black and white instead. ![DiffDir_colorspill_AA.jpg](https://archive.blender.org/developer/F303412/DiffDir_colorspill_AA.jpg) [color-spill-test.blend](https://archive.blender.org/developer/F303414/color-spill-test.blend)

Riccardo Giovanetti commented

2016-04-14 15:46:07 +02:00

Changed status to: 'Open'

Riccardo Giovanetti commented

2016-04-14 15:46:07 +02:00

Added subscriber: @Harvester

Brecht Van Lommel commented

2016-04-14 23:42:07 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2016-04-14 23:42:07 +02:00

Changed status from 'Open' to: 'Archived'

Brecht Van Lommel closed this issue

2016-04-14 23:42:07 +02:00

Brecht Van Lommel self-assigned this 2016-04-14 23:42:07 +02:00

Brecht Van Lommel commented

2016-04-14 23:42:07 +02:00

This is not considered a bug.

The direct and indirect passes are computed by dividing out the color pass, so that multiplying them gives the exact combined result again. When two objects with a different color are mixed in a single pixel, we can't cleanly separate the color and lighting and you get these colors in the direct and indirect passes.

There might be a way to compensate for this to some extent, but adding more complicated logic here will have other downsides, and doesn't really solve the issue in general anyway, with colored lights and indirect light.

This is not considered a bug. The direct and indirect passes are computed by dividing out the color pass, so that multiplying them gives the exact combined result again. When two objects with a different color are mixed in a single pixel, we can't cleanly separate the color and lighting and you get these colors in the direct and indirect passes. There might be a way to compensate for this to some extent, but adding more complicated logic here will have other downsides, and doesn't really solve the issue in general anyway, with colored lights and indirect light.

Riccardo Giovanetti commented

2016-04-15 09:35:35 +02:00

Thank you Brecht for the explanation.

Louis commented

2021-01-04 17:33:39 +01:00

Added subscriber: @Louis

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Diffuse Direct Pass Anti Aliasing color spill #48147