Decide how a physical mesh composites, from its inputs.
A physical mesh has no Luxar blending mode — that knob is refused at authoring
— so translucency is read off the data instead:
opacity < 1 is translucent, always.
transmission > 0 (glass) is translucent, always. Glass therefore does NOT
write depth, and that is the spec §3.4 contract made concrete: emissive data
behind a glass surface stays visible — crisp and unrefracted — where a
depth-writing shell would HIDE the cluster inside it, the worse failure for the
marker case this family exists for. With refractData the glass instead draws
AFTER the data and refracts it (Phase 3); the compositing state is the same,
only the ordering stamp flips.
Per-vertex alpha is translucent UNLESS an alpha_cutoff was authored, in
which case the alpha is a CUTOUT (three alphaTest) and the surface stays
opaque — the same meaning the house shader's opaque mode gives the pair.
Translucent surfaces do not write depth. With no per-triangle sort (spec §3.2)
that is the one choice that never drops a back face behind a front one; the
remaining order dependence is the ordinary alpha-over kind and is invisible on
a shell of uniform alpha.
Decide how a physical mesh composites, from its inputs.
A physical mesh has no Luxar blending mode — that knob is refused at authoring — so translucency is read off the data instead:
opacity < 1is translucent, always.transmission > 0(glass) is translucent, always. Glass therefore does NOT write depth, and that is the spec §3.4 contract made concrete: emissive data behind a glass surface stays visible — crisp and unrefracted — where a depth-writing shell would HIDE the cluster inside it, the worse failure for the marker case this family exists for. WithrefractDatathe glass instead draws AFTER the data and refracts it (Phase 3); the compositing state is the same, only the ordering stamp flips.alpha_cutoffwas authored, in which case the alpha is a CUTOUT (threealphaTest) and the surface stays opaque — the same meaning the house shader'sopaquemode gives the pair.Translucent surfaces do not write depth. With no per-triangle sort (spec §3.2) that is the one choice that never drops a back face behind a front one; the remaining order dependence is the ordinary alpha-over kind and is invisible on a shell of uniform alpha.