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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)