Luxar offset → a scalar emissive. An additive brightness shift IS an emitted
radiance, so the mapping is faithful for offset >= 0. A NEGATIVE offset (black-level
subtraction) has no physical counterpart — a surface cannot emit less than nothing —
and clamps to 0.
Luxar
offset→ a scalaremissive. An additive brightness shift IS an emitted radiance, so the mapping is faithful foroffset >= 0. A NEGATIVE offset (black-level subtraction) has no physical counterpart — a surface cannot emit less than nothing — and clamps to 0.