Author Topic: Is guncoating a metallic, dialectric or something in between ?  (Read 86 times)

Hey guys!  :)

Im currently working on a personal project involving a Mauser M712. Im trying recreate the type of materials you can see in the following images :

https://upload.wikimedia.org/wikipedia/en/9/9e/M1935A-RustBlue-FirstOiling-01.jpg?1620724875788
https://mjlmilitaria.com/wp-content/uploads/2020/03/IMG_3876-6.jpg

I tried this by using a metallic material but whenever I do a PBR-validation with substance painters build in "PBR-Validate"-filter my textures are just red. As the filter suggested the chosen base color for the material was in fact to dark to be accurate.
Following this I did some research on the metal usually used for these type of older guns manufactured in the 19th and 20th century. I found that in most cases the signature dark color comes from the bluing-process in which the surface of said metals is oxidized in order to protect it from corrosion and wear.
This would mean I was wrong all along in using a metal material and instead should have used a non-metallic/dialectric.
I tried this but didn't really get the result im looking for. This was mainly because the material was just brighter then what I observed in my reference images. Secondly I had the impression the blued steel in most images still has a very metallic look to it which I wasn't  really able to produce with a completly non-metallic surface.

My questions would be the following:

1. I looked up some gun-models on sketchfab but from what i can see most of them dont use a non-metallic material for their darker metal surfaces. So is there some sort of common standart for this type of case ? Should I just use a darker metal ?

2. Second question is based on the first one: the main reason for me not using a darker metal is because of the "PBR-Validate" filter which tells me I shouldn't. Is said filter a strict rule I should always comply with or is it more of a guidline which gives me the artistic liberty to break the rules where I see fit ?

3. Third question is based on the second one: I was able to get a somewhat pleasing result by lowering my metallic value from 1 to 0.8. This gave me a relativly dark, still metal-looking material which was still showing a green color when checked with the PBR-validation. My issue is that from what I know you dont every really wanna use metallic values other then 0 or 1, unless you are blending between a metallic and dialectric. Is this assumption wrong? Should I just go for the result that looks best ?