Cycles Glossy BSDF Specular issue #48485

New Issue

Michael P. · 2016-05-21T14:23:09+02:00

Michael P. commented

2016-05-21 14:23:09 +02:00

System Information
System: Windows 7 64bit
RAM: 4096 MB
renderer: 'GeForce GTX 760/PCIe/SSE2'
vendor: 'NVIDIA Corporation'
version: '4.5.0 NVIDIA 364.72'

Blender Version
Broken: 2.77a
Worked: (optional)

Short description of error
Cycles Glossy BSDF Specular changes into material color, instead of
light source color if the material color is "pure"

Exact steps for others to reproduce the error

The Cycles Glossy BSDF Specular should reflect the light source color,
instead of material color, when one or two of the rgb values are set
to 0, i.e. pure red rgb 255,0,0 or orange rgb 0.394, 0.153, 0

Pure black rgb 0,0,0 doesn't have any specular color at all, which
was intended I belive.

Cycles-Glossy-BSDF-Specular-issue.blend
Cycles-Glossy-BSDF-Specular-issue.mp4

**System Information** System: Windows 7 64bit RAM: 4096 MB renderer: 'GeForce GTX 760/PCIe/SSE2' vendor: 'NVIDIA Corporation' version: '4.5.0 NVIDIA 364.72' **Blender Version** Broken: 2.77a Worked: (optional) **Short description of error** Cycles Glossy BSDF Specular changes into material color, instead of light source color if the material color is "pure" **Exact steps for others to reproduce the error** The Cycles Glossy BSDF Specular should reflect the light source color, instead of material color, when one or two of the rgb values are set to 0, i.e. pure red rgb 255,0,0 or orange rgb 0.394, 0.153, 0 Pure black rgb 0,0,0 doesn't have any specular color at all, which was intended I belive. ![Cycles-Glossy-BSDF-Specular-issue.jpg](https://archive.blender.org/developer/F314030/Cycles-Glossy-BSDF-Specular-issue.jpg) [Cycles-Glossy-BSDF-Specular-issue.blend](https://archive.blender.org/developer/F314032/Cycles-Glossy-BSDF-Specular-issue.blend) [Cycles-Glossy-BSDF-Specular-issue.mp4](https://archive.blender.org/developer/F314033/Cycles-Glossy-BSDF-Specular-issue.mp4)

Michael P. commented

2016-05-21 14:23:09 +02:00

Changed status to: 'Open'

Michael P. commented

2016-05-21 14:23:09 +02:00

Added subscriber: @MichaelParucha

Michael P. commented

2016-05-21 15:24:42 +02:00

Some light color and material color combinations don't give any specular at all.

You can change the light from green to something other and then try to set the material color and again in some color combinations, there will be no specular at all.

Cycles-Glossy-BSDF-Specular-issue-2.blend

Some light color and material color combinations don't give any specular at all. You can change the light from green to something other and then try to set the material color and again in some color combinations, there will be no specular at all. ![Cycles-Glossy-BSDF-Specular-issue-2.gif](https://archive.blender.org/developer/F314040/Cycles-Glossy-BSDF-Specular-issue-2.gif) [Cycles-Glossy-BSDF-Specular-issue-2.blend](https://archive.blender.org/developer/F314039/Cycles-Glossy-BSDF-Specular-issue-2.blend)

Brecht Van Lommel commented

2016-05-21 15:46:50 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2016-05-21 15:46:50 +02:00

Changed status from 'Open' to: 'Archived'

Brecht Van Lommel closed this issue

2016-05-21 15:46:50 +02:00

Brecht Van Lommel self-assigned this 2016-05-21 15:46:50 +02:00

Brecht Van Lommel commented

2016-05-21 15:46:50 +02:00

I don't see any bug here, if you specify zero for one of the R, G or B channels it will reflect zero light for that channel.

If you want your material to have a white specular coat (as many real world materials do), then you should use a white glossy BSDF, layered over another diffuse or glossy BSDF. That is not included in a colored glossy BSDF somehow.

The only reason it appears white even with small but non-zero R, G or B channel is because the specular is very bright, and all pixels will end up with value > 1 and so are all clipped to 1. That also depends on the chosen view transform in color management by the way, the default is not the most realistic.

I don't see any bug here, if you specify zero for one of the R, G or B channels it will reflect zero light for that channel. If you want your material to have a white specular coat (as many real world materials do), then you should use a white glossy BSDF, layered over another diffuse or glossy BSDF. That is not included in a colored glossy BSDF somehow. The only reason it appears white even with small but non-zero R, G or B channel is because the specular is very bright, and all pixels will end up with value > 1 and so are all clipped to 1. That also depends on the chosen view transform in color management by the way, the default is not the most realistic.

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Cycles Glossy BSDF Specular issue #48485