Katana metalness texture practice

Randallized

So I recently made this Shinobi Katana for the purpose of getting better at using "metalness" maps. I tried giving the hamon a slightly different level than the rest of the blade and it seems to stand out more. Was wondering what people here have to say about it!

I also have it on sketchfab for full inspect: https://sketchfab.com/3d-models/golden-shinobi-katana-gameready-484fe1aa92af463abbe2e9d1fec5e71f

teodar23

It looks ok but its hard to comment on it because the slightly stylised nature of it. Also, i dont know what a hamon is and im guessing there are many others like me.
The whole render doesnt look PBR but again it might be the fact that the style is not uber realistic. If i had to guess then i'd say this is rendered in unity.
I would try to use a better environment in order to view the metallic feature better, maybe a hdri. Even if you are going for something stylised its good to test out different lighting scenarios.
Again, to my eye it doesnt look like metal, more like highly specular plastic.

Randallized

It's rendered in Blenders eevee engine. That might be why, it's intended to just be a realtime rendering engine to preview how something may look in game. ( So your guess that it's unity is not far off )

As for "Hamon":  https://en.wikipedia.org/wiki/Hamon_(swordsmithing)

It's the part of the blade at the edge where you see those white smudged lines.

JamesBrisnehan

Yah it doesn't "feel" like metal the way a PBR-type material (the type that requires a metalness map) usually does. 

Out of curiosity I looked up 'Blender and PBR', and it looks like most artists are using something called "The Principled BSDF Shader". What shader are you using?

JamesBrisnehan

Also, if you're going for a PBR Metalness workflow, I would recommend keeping the hamon 100% metal, and defining it's look in the roughness map, color map, or maybe even with an anisotropic effect. The wikipedia article says that both parts of the blade are metal, just different types.

Dethling

Maybe post the texture maps here, this would give a better insight in your workflow, so we can give feedback accordingly.

Randallized

Dethling said:

Maybe post the texture maps here, this would give a better insight in your workflow, so we can give feedback accordingly.

Oh, you can actually do this in the sketchfab model inspector, a neet little feature that site has.

Bottom right it looks like 3 planes stacked on top of each other,  then you can check each map individually.

https://sketchfab.com/3d-models/golden-shinobi-katana-gameready-484fe1aa92af463abbe2e9d1fec5e71f

JamesBrisnehan said:

Also, if you're going for a PBR Metalness workflow, I would recommend keeping the hamon 100% metal

That might be what I should have done. My roughness map has it all about the same, but I gave the hamon slightly different metalness to make it stand out more.

JamesBrisnehan said:

Out of curiosity I looked up 'Blender and PBR', and it looks like most artists are using something called "The Principled BSDF Shader". What shader are you using?

That's what I am using, Principled BSDF

Dethling

Ok, didn't saw the sketchfab link. 
Just took a look at it and you should rework the metalnes map. 
Metalnes should always be 0 (Black - for non-metal materials) or 1 (White - for ALL metal materials), greys should only used sparsely (mainly with rust etc.). 

Randallized

Dethling said:

Ok, didn't saw the sketchfab link. 
Just took a look at it and you should rework the metalnes map. 
Metalnes should always be 0 (Black - for non-metal materials) or 1 (White - for ALL metal materials), greys should only used sparsely (mainly with rust etc.). 

This may have been what I was doing wrong. Take a look at the sketchfab again ( I updated it with a new and simplified mostly B-W metalness map ) then moved the difference in Hamon detail to the Roughness/Gloss map. Interestingly, I think the Golden part of the metal actually improved more from this. The texture difference in the decorations should look a bit more distinct now.

https://sketchfab.com/3d-models/golden-shinobi-katana-gameready-484fe1aa92af463abbe2e9d1fec5e71f

Prime8

While the blade material looks quite good, I think the other materials, especially the "gold" needs some rework or I misunderstand the concept.
Right now it looks like an over saturated blend of gold and copper, do you use references for the material?
I recommend to turn down the saturation and reduce the hue shift to nearly zero.

For grim/dirt/oxidation on metal you better use black (dielectric) on the metalness map.

Dethling

The blade looks much better now, but I have to agree with Prime8, the gold looks off, mainly because of the colormap. If you work with PBR texturing you want to get as good real-world numbers as possible to set up your materials. I say numbers not reference photos and that is because the color of a material is always influenced by it's surrounding light. So you need references with pure white light and a special light setup. Since these are difficult to come by, look for reference charts (e.g. https://uupload.ir/files/jsri_materialref01.png). If you look there the color of gold isn't as saturated and red as yours, it's more like a dull bright yellow. 

If you use substance painter, don't shy away to use the preset materials as a base, they already have the right numbers. 

And for the metalnes, especially cloth is pure black (the grip) not some grey - for the start I would really stick to black and white only. Later if you feel comfortable with PBR textures, you can add some greyscale parts. 

Randallized

Thanks a lot for all the feedback, I played with the metalness a bit more, and tried making the rustier parts of the metal darker and it seems to have a nice effect as well. Also improved the normal map a bit because I noticed it had some errors. The texture is now in a much better state.

With this I have accomplished my goal of getting a better understanding how metalness map is supposed to be used. I could probably work on this one project endlessly, but it may be best to tackle more challenges.

Prime8 said:

While the blade material looks quite good, I think the other materials, especially the "gold" needs some rework or I misunderstand the concept.

The "gold" isn't really supposed to be actual gold, but just painted metal. I handpaint using Krita ( This model is entirely open-source software ). I figure most Katana would almost never actually have true gold if it was intended to be a "battle-ready" weapon. 

Dethling said:

(e.g. https://uupload.ir/files/jsri_materialref01.png)

Thanks! Will save this for future projects. Are there even bigger reference lists somewhere?

Prime8

Randallized said:

Thanks a lot for all the feedback, I played with the metalness a bit more, and tried making the rustier parts of the metal darker and it seems to have a nice effect as well. Also improved the normal map a bit because I noticed it had some errors. The texture is now in a much better state.

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The "gold" isn't really supposed to be actual gold, but just painted metal. I handpaint using Krita ( This model is entirely open-source software ). I figure most Katana would almost never actually have true gold if it was intended to be a "battle-ready" weapon. 

...

That's why I asked if you have references. What is "painted metal" in this case, it looks a bit like a metallic car paint tbh.
True, battle ready swords usually don't have massive gold parts, but of course they can have decorative gold parts or gold plating.
Most parts of a katana are made of various types of steel followed by variations of brass and bronze, please don't add rust.

I always recommend to look at references to figure out which type of materials you want to use, when creating the material itself follow @Dethling's advice.
The material on the saya is difficult to read as well, I guess it is plain wood?

Before moving to the next model I would really work a bit more on this one, you can bring it another level and take that experience over to your next project.

Dethling

Painted Metal is a material in PBR which a lot of people get wonky about. 
The issue is: The paint is non-metallic! This means the metalnes value have to be zero (black) for this material. What you can do to give it some "metal-feeling" is to remove paint at some edges (edge wear) and show some metal there (with a metalnes value of one (white)).

For the roughness I would increase the value of the cloth parts (even more "white" then the wooden parts), most cloths aren't very reflective.