Author Topic: Metal [ Reflectance ] PBR Validation  (Read 1675 times)

Hello All,

I would like to ask and hopefully, someone can shed some light on this, Wes ! Hint Hint, ! about the following.
As we all know the PBR SHADER provides for a set og guideline values to be used for correct PBR texture authoring.

So...
DIEALECTRIC
MAXIMUM 240 sRGB
TOLARANT 50 sRGB
MINIMUM 30 sRGB

METAL [ REFLECTANCE ]
MAXIMUM 255 sRGB
MINIMUM 180 sRGB ... For PURE METALS.

I have been doing some testing and am a little confused about metals which fall below the aforementioned MINIMUM 180 sRGB. For example a GUNMETAL.. Through testing with the PBR validation node inside designer I have found that the METALLIC VALUE must be lowered to 230 sRGB for any METAL [ REFLECTANCE ] bellow 180 sRGB.

Am I correct in assuming that lowering the overall METALLIC VALUE in this way would be considered the correct practice?
Of course this is not including any variations in the value due to dirt / real world usage / modulation etc. This is on a pure value basis...

Please see the attached image for reference...

If the METAL [ REFLECTANCE ] falls below 180 sRGB anything higher than 230 sRGB such as in the last example which is 245 sRGB returns a RED result in the validation node..

I just want to see if I am on the right track here or if I am understanding this correctly and if lowering the METALLIC VALUE in this way is best practice. I am writing a guide for other artists to use here at work so I have to make sure I am getting this right.

Thank you for any input.
Last Edit: November 03, 2020, 02:41:52 pm