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DigiKrafting / blender_addon_pbr

Provides a material panel that creates Metallic/Roughness or Specular/Gloss Nodes using the Principled BSDF shader.
GNU General Public License v3.0
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Principled Shader does NOT support spec/gloss workflow #6

Closed qforce85 closed 5 years ago

qforce85 commented 5 years ago

Hi,

sorry to break this to you, but it is totally wrong to use the Principled Shader for a spec/gloss workflow the way this addon does it. The reason why it's wrong is rather complex; I suggest reading the following introductions to PBR:

Physically Based Rendering Encyclopedia

PBR Guide

In a nutshell, you can't just plug a specular map from the spec/gloss workflow into the specular input of the Principled Shader, because (1) values of the specular input in the range 0-1 correspond to 0-8% of "actual" specular reflection, (2) the specular input is ignored when metalness is set to 1, and (3) the specular input is a value, whereas specular maps may contain color information in the case of metals. See also the Blender documentation on the Principled Shader.

Best regards q:-) <= Quang

qforce85 commented 5 years ago

I wrote a proposal over at Right-Click Select explaining what the specular socket really does and why it should be renamed to "Specular Level": https://blender.community/c/rightclickselect/t1cbbc/principled-shader-rename-specular-socket-to-specul

DigiKrafting commented 5 years ago

Thank you for letting me know, I created this addon after watching some video tutorials on the then, new shader, I'll update the specular nodes when I have some free time.