Material Data

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PBR

rock ref: https://www.alexstrekeisen.it/english/meta/maficgranulite.php rock sudety: https://zywaplaneta.pl/granulity-sudety/

Related notes: Color, Rendering

Color theory bible Convert colors calculator

Substrate (Strata)

more expresive workflows, can combine 2 shaderws toghether No cost if input is not used ! Layer system - layering is expensive if possible make with onslab Slab « is a material matter responce to light. = interface + medium

G buffer

Gbuffer Format (projection) Adaptive - packed data noi blend like decal ??? - play 5 & xboix series SM6 - pit packed uav to encod per pixel « full Blendable - not fully but safe and low compatibility, ok for transition.

https://youtu.be/KYmd_LNlw2c?t=2125

YT unreal fest - Everything You Wanted to Know About Substrate(But Are Too Afraid to Ask)| Unreal Fest Stockholm 2025 YT Render Bucket - UE5.7 Substrate – Next-Gen Shading Workflow Explained - YT Beyond Extent and Hugh Chew https://youtu.be/4X-nZ7qflcw - base to advanced substrate

![[Pasted image 20251127035117.png]]

Slab BSDF

BSDF - Bidirectional scattering distribution functions -

Monolithic

complex stand alone phenomena non composible Volumetric Hair Eye Unlit, Single layer water.

Wyjątki: Monolithic / Domain Materials Still benefit from substrate

post pro , Light fn, decal

decal > convert to decal

  default value     Order of dops during simpli fication    
Albedo -         medium
F0 v3 (metlic / specularity) (0.04, 0.04, 0.04) Reflectivity Reflection at facing angle   if f0 increase diffuse response lower interface
F90 (metlic / specularity) 1 Reflectivity Reflection at shilluete. 5 Simple adobe use F82 (specular edge) - Hue and saturation shift relative to F0 value interface
Roughness   Roughness     spread of the highlight interface
Anisotropy   Roughness Stretching highlights 2 Complex   interface
Normal (0.5, 0.5, 1)         interface
Tangent           interface
SSS MFP 0 cm   Subsurface mean free path - Opacity 5 Simple density of material and effect of absorption how RGB answer to depth
Large values can be noisy !, best on translucency		 medium
SSS MFP Scale Negative values negative scattering, 0 - scatter in both dir     5 Simple   medium
SSS Phase Anisotropy       5 Simple   medium
Emissive            
Second Roughness   Roughness   3 Complex   interface
Second Roughness Weight 0 is using only first and 1 will use only second. Roughness   3 Complex   interface
Fuzz Roughness   Fuzz Emulate fuzz 4   interface
Fuzz Amount   Fuzz   4   interface
Fuzz Color   Fuzz   4   interface
Glint Dens       1 Most complex    
             
  • f0 is a color - any material can exibit chromatic specular (oxide, oil films)
  • energy conserving by design. if F0 increse then diffuse responce decrese
  • medium > sss, translucent, semi transparent , skin glass soft plastic

Clasic domains (Domain matrial) will not blend: Decal, Light fn, Post-pro, Volume, Hair / Eye, Unlit, Single Layer

SSS

E-num on slab node:

  • wrap
  • two-sided wrap
  • diffusion
  • simple volume

IRO

Metal

SMF Metal - node help to convert metallic workflow but can be achieved by Diffuse Albedo and F0

  • Diffuse - diffuse is separated so 0,0,0
  • F0 - should be color of metal
Silk fabric
Thin-film
  • f0 & f90
  • dif - 0

Blend Materials

Add - not physically correct braking energy conservation by suming contribnution postevaluated. Use for emissives! Horizontal layers blend materials - if blend factor is 0/1 is only 1 else < eveluate both (only on blends)

  • background / foreground Vertical layers - one on top of other and define what thick first layer is. Expensive
  • top / bottom with thickness (Non 0 MFP if 0 ius considered opaque and not evalueated) Coverage weight (how strong material is) Select - Condition (can be smooth with TAA) ONLY WAY To blend mat with different SSS !!!!

![[Pasted image 20251227032045.png]]

Example glass

Material details:

  • set refraction model (and then IRO in material)
  • mode
    • tintied glas - transl col transm
  • Ligth mode
    • surface forroward sjhading (expensive)

Slab BTDF

Transmision

Slab BSDF

Bi-Directional Scattering distribution Fn. Outer and inner surface toghether

PBR

Guideling how to author textures Energy conservation. Light reflected or absorbed Metal in PBR - base color is reflection tint - metal reflect much more in facing angles as specular. (non metal 4-7%) and all materials reflect 100% at shilluete edge angle Roughness - how smooth on fine level (microfacet like).

Metallic Workflow

Albedo / Reflectance

Diffuse reflected color for dielectric - flat lower contrast and brighter than normal photography Reflectance value for metals Brightness should be between: 50 - 245 (sRGB) / 0.02 - 0.9 (Linear RGB)

Dielectrics Median luminosity:

Mat Linear Linear byte sRGB sRGB byte
Black 0.013 5 0.117 30
Gray (Zone V) 0.18 46 0.5 128
White 0.893 229 0.95 249
         
Black Paint 0.02 - 0.027 5 - 7 0.169- 0.195 43 - 50
Coal
Carbon
Asphalt (Fresh)		 0.02 - 0.04      
Brright Gray 0.5 128 0.72 186
White acrylic paint 0.81 243   230
Fresh snow 0.90   0.95 240
         
CONCRETE        
Fresh concrete 0.51 - 0.55 192,191,187 0.67  
Worn asphalt 0.08- 0.15   0.42  
Old Concrete 0.3 135,136,131 0.57  
White cement 0.7   0.85  
         
ROCK        
Limestone 0.3 - 0.45     148 - 177
         
Rock 0.3 - 0.4     148 - 168
         
SOIL        
Sand 0.440,0.386,0.231   0.694,0.655,0.518 177,167,132
Desert sand 0.36 - 0.40 Dry 177,167,132 0.65  
Sandy Soil 0.25 - 0.45 Dry     136 - 177
Clay Soil 0.23 - 0.4 Dry 137,120,100   131 - 168
Grey soil 0.1 Wet 0.3 Dry     90 - 148
Silt loam Soil 0.23 - 0.28 Dry     131 -143
Bare soil
Dark earth		 0.13 - 0.17 Dry     114
Yellow Clay 0.16     111
Black soil 0.08 Wet 0.15 Dry     81 - 108
         
FOLIAGE        
Green grass 0.2 - 0.25   0.53 123 - 136
Tundra 0.2     123
Tall wild grass 0.16 - 0.18     111 - 117
Tea bushes 0.16 - 0.18     111 - 117
Corn field 0.16 - 0.17     111 - 114
Deciduous tree 0.15 - 0.18     108 - 117
Grain crops 0.1 - 0.25     90 - 136
Moss 0.1     90
Summer Foliage 0.09 - 0.12     85
Autumn Foliage 0.15 - 0.3     109 -148
Conifer Forest 0.08 - 0.12     81
Leafs 0.07 Wet 0.2 Dry     75 - 123
         
WOOD        
Batten planks
(fresh wood)		 0.35 - 0.42     158 - 172
Batten planks
(old weathered)		 0.12 - 0.16     97 - 111
Varnished wood 0.13     101
Bark, oak 0.1     90
         
WATER        
Ocean Ice 0.56 ( 0.5 - 0.7)      
Water sun horizon 0.5 - 0.8      
Water sun zenith 0.05      
         
SKIN        
Skin European 0.35 - 0.6     158 - 202
Skin Indian 0.15 - 0.3     108 - 148
Skin African 0.05 - 0.15     65 - 108
         
Metal
    180 / 186 - 255 (sRGB)

A database of physically based values for CG artists

Specular

Dielectric F0 Reflectance Unreal values 0-8%. Thus default value is .05 (which is 4% reflective)
Value = ( (1 - IOR) / (1 + IOR) )² Fresnel reflection coefficient mount of light that reflects off a surface when the viewing angle is perpendicular (i.e., the angle of incidence is 0 degrees).

Let the material value in unreal be default 0.5 and multiply by a cavity map to darken cavities.

specular reflectance values (denoted as “F0”) specular reflectance refers to the amount of light reflected at a particular angle from a surface.

Wood - 0.02 to 0.05 natural stones like granite or marble, the F0 value can range from 0.02 to 0.05.

Depending on factors like moisture content and leaf type, F0 values can vary, but they may range from 0.03 to 0.08. F0 values for healthy green leaves typically range from around 0.03 to 0.08. Dry or Wilted Leaves: Leaves that are dry or wilted may have slightly lower F0 values, possibly ranging from 0.02 to 0.06.

| Mat | sRGB | | —- | —- | | Plastic | 55-64 | | Rusted metal | 52 | | Water | 43 | | Ice | 41 | | Glass | 57 | | Gold | 255 226 155 | | Silver | 252 250 245 | | Aluminium | 245 246 246 | | Iron | 196 199 199 | | Copper | 250 506 192 | metal 0.7 - 1 specular

Roughness

Microfacets models how rough (in microscale) mat is (amp & freq of bumps in material ) tiny imperfections in mat & angle of incoming lightEverything has Fresnel and reflections ! YT link The specular part of Disney “principled” BRDF is a GGX BRDF. It use a roughness parameter. Nm is crucial! more direct reflection and depends heavily on the viewing angle relative to the light source and the surface normal.

  • reflection on angle is more sharp and visible
   
0 -0.2
polished / wet
0.2-0.5 smooth
0.5-0.8 rough
0.8-1 matte
Mat UE
Air  
Ice 0.224
Water 0.255
Milk 0.277
Skin 0.35
COMON 0.5
Glass 0.5
Plastic 0.5
Quartz 0.57
Diamond  
Rubbet .8 ?

argiles - ziemia like craie sable (kamienie zółtawe) calcaire = limestone (kamienie szare jane z białymi przetarciami) schistes = łupki granite

Metal

| Mat | | | —- | —- | | Conductors | 1 | | Dielectrics | 0 | | Diamond | |

  • Conductors Spec and glossy reflection, in conductors typically metals. dep on wave len (yellow gold) (reflect most light and turn non reflected into heat)
  • Dielectrics - (BTDF shader ie) reflected and refracted (IOR,bend ing rays on medium change) sometimes scatter (as subsurf) and flat ss is difuse Conductors - (typicly reflect depend on wave leng. give color)
    Dielectrics - (reflect + refract + scatter refracted (subsurf but rather difuse ))
    Refl + refr » have fresnel.

Advanced Render passes

Refraction

  • physical model of Index of Refraction - but you will have an offset that reads from off screen, shift material glitches can occure.
  • Pixel Normal Offset enables refraction for these large flat surfaces, like water,
Mat   IOR
COMON   1.5
Air   1
Ice   1.31
Water   1.33
Milk   1.35
Skin    
Glass   1.52
Plastic   1.46
Quartz   1.544 - 1.644
Diamond   2.42 
Water:
Total internal refl - speed of light in mat to speed of light oudisde.....   IRO
- from top only go inside
- low light reflect
AIR speed of light > 1.0 iro
speed of light in water slower
so AIR to water 1.33

SSS

To use this feature, enable Burley in the Subsurface Profile and set the Editor Preview Level to Cinematic. If you’re already using Separable SSS profile, minimal changes are required to switch to this method. Note that Burley SSS requires Temporal Anti-Aliasing to work properly.

Anisotropy

Specular Workflow

Strata

  F0 f90
Plastic 0.04 most materials default in unreal  
  • metal pure reflection > only refraction (or absorbed [heat]) > only mat that tint reflection (but saturate with Fresnel)