PBR Cheat Sheet

the values that keep shading physically plausible · click to copy

…measured metals

Ground rules

Dielectric albedo stays inside 0.02 – 0.9 linear. Nothing real is pure black or pure white — coal is ~0.02, fresh snow ~0.9. Check the albedo table for real anchors.
Metal base color = its specular color, and it's bright. Measured metals sit at roughly 55 – 100% linear brightness; a dark "metal" usually means dirt, oxide or paint — which are dielectric layers.
Almost every dielectric reflects ~4% at F0. That's IOR 1.5. Tweaking spec intensity per material is rarely needed — tweak roughness instead.
Metalness is binary at the pixel level. Values between 0 and 1 only belong on transition pixels (edge anti-aliasing, layered dust) — not as a look-dev dial.
Roughness carries the story. Fingerprints, wear, smudges and dust read through roughness variation long before color changes.
Energy is conserved — trust the model. If a material looks too dark, fix lighting or albedo, don't boost specular past physical.
Reference is measured, not remembered. Eyes adapt; photograph a gray card / chrome ball when you can, and use measured tables when you can't.

Diffuse reflectance of the surface itself, lighting excluded. If your grass texture averages 0.5 it will glow in any correct renderer.

Map	Space
Base color / albedo	sRGB no lighting, no AO, stay in the 0.02–0.9 linear band
Normal	Raw / non-color green channel: OpenGL Y+ (Blender, Maya, Unity, Substance default) vs DirectX Y− (Unreal, 3ds Max)
Roughness	Raw / non-color grayscale; where the surface story lives
Metalness	Raw / non-color binary per pixel; gray only on AA/transition pixels
AO	Raw / non-color into the dedicated AO slot — never baked into albedo
Height / displacement	Raw, 16/32-bit 8-bit height = stair-stepping artifacts
Emission	sRGB (usually) HDR values via intensity multiplier, not the map
Opacity / masks	Raw / non-color grayscale data

Material	IOR	F0	F0 (8-bit)
Water			5
Ice			5
Eye cornea			6
Skin			8
Plastic (acrylic)			10
Glass (soda-lime)			11
Amber			12
Flint glass			14
Sapphire / Ruby			20
Cubic zirconia			34
Diamond			44

F0 = reflectance at normal incidence. The Fresnel-curve calculator plots the full angle falloff.

F0 = ((ior − 1) / (ior + 1))²…and back: ior = (1 + √F0) / (1 − √F0)
specular slider = F0 / 0.08the 0–1 "specular" input (Disney/UE): 0.5 ≡ F0 0.04 ≡ IOR 1.5
glossiness = 1 − roughnessspec/gloss ↔ metal/rough workflows; invert the map, nothing else
α = roughness²most modern shaders square the artist value (Disney remap) before GGX — if a port looks too sharp or too blurry, this is why

GGX perceptual bands — squared-roughness ("roughness²") inputs shift these lower.

tile = 1001 + u + 10 × v

u and v are 0-based tile offsets; a row holds 10 tiles (u 0–9), then v steps up. Filename token: texture.<UDIM>.exr.

✕Baking lighting or AO into base color — kills the material under any other lighting.
✕sRGB tag on data maps (normal/roughness/metal) — subtly wrong shading everywhere.
✕Wrong normal-map handedness — bumps light from the wrong side; flip green, don't resculpt.
✕Pure 0.0 or 1.0 roughness across a whole surface — nothing real is uniform; add variation.
✕Dark metal albedo — real metals are 55–100% bright; dark = it's actually a dielectric layer.
✕Metalness used as a mix-dial — it's a per-pixel binary, not a look-dev slider.
✕Specular sliders touched before roughness — 0.5 (F0 0.04) is right for almost everything.
✕8-bit displacement maps — visible terracing; use 16-bit minimum, 32-bit float for terrain.

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