pbr: better flow of mat info through light calc
pbr: better flow of mat info through light calc

zenmumbler/stardazed-tx,zenmumbler/stardazed-tx,zenmumbler/libzm,stardazed/stardazed,zenmumbler/libzm,stardazed/stardazed-tx,stardazed/stardazed,zenmumbler/stardazed-tx,zenmumbler/stardazed-tx,zenmumbler/libzm,stardazed/stardazed-tx,zenmumbler/libzm,stardazed/stardazed-tx