Documentation / scene / PHYSICAL_BAKE_EXPOSURE

Variable: PHYSICAL_BAKE_EXPOSURE

const PHYSICAL_BAKE_EXPOSURE: number

Defined in: libs/scene/src/utility/physical.ts:65

Fixed exposure the physical sky bake (IBL, distant-light LUT, baked skybox) is stored at, equal to the Sunny-16 reference: 1 / 38400 === calculatePhysicalExposure(16, 1/125, 100).

Remarks

The bake is cached and only invalidated when the sun changes, so it cannot carry the live camera exposure. Nor can it hold raw photometric luminance: the environment cubemap is rg11b10uf (max ~65,024) or rgba16f (max 65,504), while a 100,000 lux sun drives the atmosphere model to ~384,000. That overflows to Inf in the sun's direction, and the GGX prefilter plus the SH projection then spread the Inf across the entire IBL.

Storing at this fixed reference keeps the bake exposure-independent and in range. Consumers convert to the live exposure with cameraExposure / PHYSICAL_BAKE_EXPOSURE.