NormalMapProvider

const NormalMapProvider: MaterialEffectClass<{ normalMap: () => Texture <unknown> | null; }>

Defined in: packages/presets/src/lighting/NormalMapProvider.ts:36

Provides the ‘normal’ and ‘elevation’ channels from a pre-baked normal atlas.

Atlas encoding (see @three-flatland/normals/bakeNormalMap): R = nx ∈ [-1, 1] → mapped from [0, 255] G = ny ∈ [-1, 1] → mapped from [0, 255] B = elevation ∈ [0, 1] → mapped from [0, 255] A = source alpha

The provider reconstructs nz = sqrt(max(0, 1 − nx² − ny²)) at runtime — outward-facing tangent-space convention means nz ≥ 0 always, so the sign is implicit and one texture channel is freed for elevation.

Instance-flip correction: sampled normal.xy is multiplied by the existing instanceFlip attribute so a flipX/flipY sprite responds to lights from the geometrically-correct side.

Elevation drives DefaultLightEffect’s per-fragment light direction (L.z = lightHeight − elevation). Different normalMap textures produce different materials and therefore different batches.

Example

import { NormalMapProvider } from '@three-flatland/presets'

const provider = new NormalMapProvider()
provider.normalMap = myNormalMapTexture
sprite.addEffect(provider)