Tagged union shared by all three presets. Pick exactly one sky source per
pipeline; the preset wires the matching feature in as the first writer of
frame.hdr so downstream lit/composite passes load it.
'none' — no sky. The first lit pass clears HDR itself; suitable
for samples that draw their own opaque background or
don't care.
'atmosphere' — procedural scattering via AtmosphereFeature. When
useMultiscatterLut is set, AtmosphereLutsFeature
is registered automatically so the LUT pair is available.
'passthrough' — AR: clears HDR to fully transparent (alpha 0) so the
real-world camera feed shows through where nothing draws.
Opaque geometry writes alpha 1, becoming the coverage mask;
pair with an immersive-ar session (the engine sets
frame.transparentBackground, so the tonemap preserves the
alpha to the projection layer).
Tagged union shared by all three presets. Pick exactly one sky source per pipeline; the preset wires the matching feature in as the first writer of
frame.hdrso downstream lit/composite passes load it.'none'— no sky. The first lit pass clears HDR itself; suitable for samples that draw their own opaque background or don't care.'color'— flat-color clear via ConstantColorSkyFeature.'texture'— equirectangular HDR panorama via SkyTextureFeature.'atmosphere'— procedural scattering via AtmosphereFeature. WhenuseMultiscatterLutis set, AtmosphereLutsFeature is registered automatically so the LUT pair is available.'passthrough'— AR: clears HDR to fully transparent (alpha 0) so the real-world camera feed shows through where nothing draws. Opaque geometry writes alpha 1, becoming the coverage mask; pair with an immersive-ar session (the engine setsframe.transparentBackground, so the tonemap preserves the alpha to the projection layer).