Materials

material is a discriminated union on shader. Each model accepts only its own options. All accept roughness and roughnessScale. Every numeric option takes a plain number, a PhotonValue, or a callable signal.

lambert (default)

Option	Type	Default
ambient	number	0.2

phong · fresnel

Option	Type	Default
ambient	number	0.2
shininess	number	32
highlightColor	string	white

cell

Option	Type	Default
ambient	number	0.2
steps	number	3
smoothness	number	0.1

matcap

Option	Type	Default
shininess	number	32
highlightColor	string	white

Takes no ambient.

anisotropic

Option	Type	Default
ambient	number	0.2
shininess	number	32
smoothness	number	0.1
highlightColor	string	white
grain	number	0
grainScale	number	0.5
grainType	'dot' | 'line'	'line'

Fabric’s own model. Not the same as glass’s anisotropy, which smears a background sample rather than shading a surface.

roughness on every shader

Option	Type	Default
roughness	number	0
roughnessScale	number	0.5

On a lit shader roughness bumps the normal with noise at roughnessScale frequency. On glass it blurs the refracted image instead — see below.

glass

shader: 'glass' moves the shape to its own pipeline. Instead of lighting a surface it refracts the frame — Glass walks the ten stages. The options are listed here in the order the shader uses them.

<Box position={[1.42, -2, -1.52]} size={{ x: 0.6, y: 0.6, z: 0.6 }} roundness={0.4} color="#e70ae7"
  material={{
    shader: 'glass',
    thickness: 2, ior: 1.09, fresnel: 9, fresnelColor: '#ffffff', outline: 0.4,
    attenuationDistance: 100, attenuationColor: '#ffffff',
  }} />

Two of the shape’s own props change meaning on glass:

Shape prop	On a glass shape
color	A tint multiplied into the refracted image. Default white — no tint.
opacity	The tint’s strength, 0–1, default 0.9. Not transparency: a glass shape always covers its pixels.

Refraction

Option	Default	What it does
ior	1.5	Index of refraction. The ray bends by 1/ior entering and by ior leaving; values below 1.0001 are clamped. Also sets the base reflectance metalness uses.
thickness	0.3	World units the exit ray travels before the backdrop is read — the lever on how far the image shifts. 0.3–0.6 reads as glass, 1–3 as a lens.
refraction	'volume'	'volume' bends at the front, walks the shape’s real depth to the back surface and bends again there. 'slab' bends once and walks thickness from the front — three.js’s model: thin edges bend as hard as the middle, the back surface plays no part, and thickness is a plain distance.
innerSteps	12	Steps of the inner march that finds the exit surface, clamped to 1–40. A sphere ignores it: its exit is solved exactly.
chromaticAberration	0	Fraction of the refraction offset by which red and blue are read on either side of green.
roughness	0	Blur of the refracted image: 0–1 picks mip 0–5 of the background copy. Stored as a byte.
anisotropy	0	Smears the read along a direction — five taps weighted 1·4·6·4·1, spaced 0.015 × anisotropy in screen space — and raises the mip.
anisotropyRotation	0	The smear direction in radians; 0 is horizontal.
anisotropyBlur	0	Extra mip bias on the smear so it reads as a streak rather than five copies. Counts as blur even with anisotropy at 0.
distortion	0	Warps the read position with a noise field; full amplitude moves it by 0.05 of the screen.
distortionScale	1	Frequency of that noise, in world units.
temporalDistortion	0	Drifts the noise with scene time so the warp animates. Inert unless distortion is above 0.

Absorption

Option	Default	What it does
color	#ffffff	The colour assumed behind pixels where the canvas is transparent — the page. The canvas is premultiplied, so a refracted read of an empty pixel is composited over this.
attenuationDistance	1e6	Beer–Lambert: light that travels this far through the glass arrives as attenuationColor. The default is clear.
attenuationColor	#ffffff	The colour after attenuationDistance of travel. White is clear; the tint deepens with the path length through the volume.

Surface

Option	Default	What it does
fresnel	0.4	Rim strength: (1 − N·V)^5 × fresnel mixes toward fresnelColor.
fresnelColor	#ffffff	Rim colour. Black makes a shadow rim.
grain	0	Perturbs the surface normal with noise before the ray bends, 0–1.
grainScale	300	Grain frequency, 400 + 6 × grainScale. Higher is finer.
iridescence	0	Thin-film interference, 0–1.
iridescenceThickness	400	Film thickness in nanometres, ~100–800.
metalness	0	Mixes toward a mirror in attenuationColor, shaped by the ior-derived Fresnel. 1 is a mirror.
clearcoat	0	A polished top layer: a white Schlick rim with its own roughness, above metalness and below the fresnel rim.
clearcoatRoughness	0	0 sharp rim, 1 broad halo.
sheen	0	A broad soft rim, (1 − N·V)², in sheenColor.
sheenColor	#ffffff
outline	0	Darkens the silhouette to black, (1 − N·V)^8 × outline.

Reflection

Option	Default	What it does
reflection	0	Screen-space reflection of the shape pre-pass along the mirrored ray. Needs enableReflection on <Scene> — the flag multiplies the strength, so without it the option is inert. Mirrors other SDF shapes only, never particles, text or the mesh, and only a shape nearer than the glass surface: one behind or inside the glass refracts but does not reflect.
reflectionRoughness	0	Mip bias on that read, 0–5, from the shape mip chain.
gloss	0	A procedural studio environment — sky, ground, two bulbs — read along the reflected direction. Needs no scene flag.
glossSharpness	0.7	Bulb tightness, mapped to an exponent of 4–256.
glossCoverage	0.18	Schlick F0: 0 rim only, 1 the whole surface.

What glass ignores

• Modifiers, at a sphere’s exit. Glass takes modifiers like any shape and its surface march follows them, but under refraction: 'volume' a sphere’s exit is solved from its bare radius.
• <Effect> outline and glow. Their slots hold attenuation and distortion on a glass shape; only the outline thickness survives, as envelope padding.
• <Fast>. A glass shape inside <Fast> is counted as fast and drawn by the fast pipeline, which has no glass branch — it lights as lambert.

A glass <Mesh> takes the same set plus four silhouette options — see Mesh › MeshMaterial.

roughness, anisotropy, anisotropyBlur and reflectionRoughness each pull in a mip chain. Every other option is arithmetic in a shader already running.