Materials
A material decides how a surface looks. Every field, with its range and default, is in the generated component reference; which maps each type accepts is in material maps. This page is how to use them.
A material is a list of slots
Not one material — a list. Slot order follows the submeshes of an imported model, so slot 1 paints the first group, slot 2 the second. That is how one chair is wood and fabric.
Objects you build from a primitive have a single slot, and that is usually all they need.
Reordering them does not rebuild anything, and a slot keeps its settings when you move it.
Choosing a type
| Type | Reach for it when |
|---|---|
standard | you want it to look real — the default choice |
physical | you need glass, varnish, a clear coat, refraction |
basic | you want flat colour that ignores lighting |
toon | you want stylised, banded shading |
normal | you are debugging a surface |
chromakey | you have video with a colour to remove — a green screen |
occluder | you want an invisible shape that hides things behind it |
ref | you want to reuse a material saved as a resource |
Switching type changes which settings exist, so the panel shows fewer or more fields.
The settings every type shares
| Setting | Does |
|---|---|
color | the base colour |
opacity | 0 to 1 |
transparent | must be on for opacity below 1 to have any effect |
side | which faces are drawn: front, back or both |
wireframe | draw the edges only |
visible | draw it at all |
What each type adds
| Type | Also has |
|---|---|
standard | metalness, roughness, emissive, emissiveIntensity |
physical | all of the above plus clearcoat, clearcoatRoughness, transmission, thickness, ior |
toon | emissive, emissiveIntensity, and a gradient ramp |
normal | flatShading, and no colour |
chromakey | keyColor, similarity, smoothness, spill — transparent by default |
occluder | only side |
If a surface looks wrong, adjust roughness first. Metalness is close to binary in reality — something either is bare metal or it is not — and values in between mostly read as mistakes.
The physical extras
clearcoat is a lacquer layer over the top: car paint, varnished wood, a phone screen.
transmission with thickness and ior is how you get glass and liquid — light passing
through and bending rather than bouncing off.
Left at their defaults they are folded away at compile time, so physical runs exactly as fast
as standard. Turning transmission on does cost real work — the browser draws the scene twice —
so use it where it earns its place.
Texture maps
Every map is the image plus its options. Setting just the image is usually enough; the options are where you fix a texture that tiles wrongly or looks stretched.
| Option | Controls |
|---|---|
repeat, offset, center | how it tiles and where it sits |
rotation | in degrees |
wrapS, wrapT | repeat, clamp or mirror at the edges |
magFilter, minFilter | how it is sampled close up and far away |
anisotropy | 1–16 — sharpness at grazing angles |
generateMipmaps | smaller versions for distance |
colorSpace | how the image's values are interpreted |
channel | which UV set to use, 0–3 |
flipY, premultiplyAlpha | orientation and transparency handling |
An image carrying colour and one carrying numbers — roughness, a mask, a height map — must be interpreted differently. Get it wrong on a roughness map and the surface looks subtly, inexplicably off. If a map is not a picture, it is data.
Which maps each type accepts: material maps.
Reusing a material
Two different mechanisms, and the difference matters:
| You want | Use |
|---|---|
| A starting point you then tweak per object | Replace from library — it copies the values |
| One material shared, edited in one place | a ref slot pointing at a material resource |
The library has three sources: this project, your team, and the platform's creators hub. Applying from any of them copies; editing afterwards affects only that object.
Copying is right for "start from this and diverge". A reference is right for "these forty objects are the same material" — change the resource once and all forty follow.
Two special ones worth knowing
Occluder is the AR trick: an invisible shape that hides whatever is behind it. Put one where a real pillar stands and your virtual content disappears behind it properly, which is most of what sells the illusion.
Chroma key removes a colour from a video — a green screen, so a filmed person can stand in
your scene without a rectangle around them. Tune similarity until the background goes,
smoothness to soften the edge, and spill to take the green tint off the subject's edges.
Beyond the fixed types
If none of this expresses the look you need, build the material as a graph instead. The built-in types are points in the same system, so a graph is not a downgrade. → Material graphs
Next: Physics