Make mat unlit: the base color is output directly, bypassing all lighting, IBL,
and tonemap (matches KHR_materials_unlit). Optional unlitColor is a linear-RGB tint
applied to the base color. Registers the unlit extension globally (idempotent). Call
before the scene is first built.
Make
matunlit: the base color is output directly, bypassing all lighting, IBL, and tonemap (matchesKHR_materials_unlit). OptionalunlitColoris a linear-RGB tint applied to the base color. Registers the unlit extension globally (idempotent). Call before the scene is first built.