filament-compose/io.github.erkko68.filament.compose.scene/DirectionalLight

DirectionalLight

fun FilamentSceneScope.DirectionalLight(direction: Direction = Direction(0.3f, -1f, -0.5f), color: LinearColor = LinearColor(1f, 1f, 1f), intensity: LightIntensity = LightIntensity.LuminousPower(100_000f), shadow: ShadowConfig? = null, castLight: Boolean = true, lightChannels: Set<Int> = setOf(0), followGroupRotation: Boolean = true)

A directional light — parallel rays from infinitely far (the classic "sun" for shading, without the visible disk; use SunLight for that). Only directional and spot lights can cast shadows.

DirectionalLight(
    direction = Direction(0.3f, -1f, -0.5f),
    intensity = LightIntensity.LuminousPower(100_000f),   // lux
    shadow    = ShadowConfig(mapSize = 2048, cascades = 3),
)

Parameters

direction

Light direction in world space (need not be a unit vector).

color

Linear-sRGB colour; channels may exceed 1 for an over-bright tint.

intensity

Brightness and its unit as one value (LightIntensity) — lux/lumen, candela, or watts + efficiency.

shadow

Shadow-map config (ShadowConfig), or null for no shadows.

castLight

Whether the light emits illumination (false = shadow-only).

lightChannels

Which channels (0–7) this light affects; a renderable is lit only if it shares an enabled channel. Channel 0 is the default.

followGroupRotation

When inside a Group, re-aim direction by the group's rotation each frame, matching how meshes rotate with their group (e.g. a sun rig that tilts with its parent). On by default; set false to keep the light's aim fixed in world space.