Unity - Anisotropic - Silk Material

Article directory

Purpose
environment
[Fake] silk with subjective artistic effect
Physics-based approach
Station A reference
Project
PBR filament web capture
References

Purpose

Scavenge, backup

environment

Unity : 2020.3.37f1
Pipeline : Builtin Rendering Pipeline

[Fake] silk with subjective artistic effect

very simple :

half specualr = pow(1 - NdotV, _Edge_Pow) * _Edge_Scale + pow(NdotV, _Enter_Pow) * _Center_Scale;
specular *= _Tint;

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This effect is not physical
and the effect is relatively weak on regular planes

Reference below: Cilory-UE4-Silk material You can see that when the silk fabric moves, it is slightly more noticeable
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Physics-based approach

Refer to Google's pbr filament documentation (code + documentation)

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Experimental results 1 - blinn phong modified specular to anisotropy model

This is the sheen of ordinary clothes, as shown below:
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Anisotropy model lighting is used, as shown below:
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This is the luster of silk clothes. The simple test DEMO is as follows (non-PBR)

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Optimized normal application changes to T (tangent) for anisotropic materials
Complete other fresnel, reflection, ambient supplements

I used the blinn phong model for the above effects, and applied the PBR Anisotropy effect to the highlights.

Then the following is the effect of adding PBR Anisotropy to the standard metal flow of the unity builtin rendering pipeline (built-in pipeline)

Experimental results 2 - Unity BRP standard (metallic flow) shader modified sepcular to anisotropy model

The reference is: the anisotropy effect in PBR Filament:

The first step is to directly light the specular highlight part

https://google.github.io/filament/Filament.html#materialsystem/anisotropicmodel

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The second step is the normal of IBL's reflect

The second step is to distort the cubemap reflect dir (that is, IBL's Anisotropy, which is to modify the reflect dir.In fact, I directly modify the normal here, so reflect(-v,n ) modifies the reflect result)

https://google.github.io/filament/Filament.html#lighting/imagebasedlights/anisotropy
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Final viewing effect

Substitute the PBR Aniso effect in standard, as shown below:

On the left blinn phong changes specular to anisotropy specular
The middle standard metal flow is modified to anisotropy specular
On the right is the ordinary standard metal flow

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Experimental results 3 - anisotropy model fine-tuning glossy and normal tilling

Model on PBR Filament, testing the effect of changing Standard to Anisotropy Specular

Show standard metal flow
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Turn on anisotropy
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Then we add another detail normal
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The basis is too thick, adjust the scale offset
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The final effect
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Add Bloom, Color Grading (tonemapping) after-effects
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I found a texture on the Internet, and I temporarily used it as MGA (metallic, glossy, ao) and normal, and the effect was quite good.
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Then I photoshopped a few pictures with different tilling
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The normal effect is more delicate
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Experiment result 4 - Add detail albedo, mix, normal functions

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Station A reference

Then search for "fabric" on station A. There are also Chinese people uploading their own practice works there, which is also very OK
https://www.artstation.com/search? sort_by=relevance&query=%E5%B8%83%E6%96%99

Some also note the DCC software used (basically DS/SD: Substance Designer and mamoset eight monkeys)
https://www.artstation.com/artwork/ lxdkzo

For example, this material
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The texture used is as shown below
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The texture channels used are:

TO THE
BaseColor
Height Map
Roughness
Normal

Basically, they are the channel diagrams of our PBR materials.

References in station A:

https://www.artstation.com/artwork/lxdkzo
https://www.artstation.com/artwork/B1KG8r
https://www.artstation.com/artwork/B1KG8r
https://www.artstation.com/artwork/kDrVZy
https://www.artstation.com/artwork/L3XWNP
https://www.artstation.com/artwork/48KDYl
https://www.artstation.com/artwork/Zeq9P8, this is very beautiful. It uses Substance 3D Designer for texturing, Marvelous Designer for cloth settlement and baking, and Marmoset Toolbag for rendering.
https://www.artstation.com/artwork/KOJk19
https://www.artstation.com/artwork/d0vLYW
https://www.artstation.com/artwork/4Xzea8
https://www.artstation.com/artwork/VyY92R
https://www.artstation.com/artwork/2qOzgA
https://www.artstation.com/artwork/2qOzgA
https://www.artstation.com/artwork/rAr3xm, this is also very beautiful, also SD + Eight Monkeys
https://www.artstation.com/artwork/OmblEb