UNKNOWN_97 might be RTL lightmap data

[snake-biscuits]

Hex	Decimal
0061	97

The Apex Legends change to .bsp_lump-only lumps means some of RTL's data is lost (RTL-C)
LIGHTMAP_DATA_UNKNOWN might be some of the extra texels

IT IS NOT RTL.C, they co-exist before the switch to .bsp_lump only

LIGHTMAP_DATA_UNKNOWN is always 4/13ths of RTL.length & 1/3 of RTL.filesize

LIGHTMAP_DATA_UNKNOWN.length + RTL.filesize != RTL.length

RTL is the only lump where .bsp & .bsp_lump sizes differ (9 vs 8 bytes per texel)

NOTE: LIGHTMAP_DATA_UNKNOWN immediately preceeds LIGHTMAP_DATA_SKY in the lump order

Related

• Titanfall Engine lightmaps #89

[snake-biscuits]

Season 18 .bsps aren't the best for checking this out atm, since we don't have access to LIGHTMAP_HEADERS:

• Apex Legends Season 18 `.vpk` are gone #121

We can now extract all .wrap

However, it would be worth checking if (49, 1), (50, 1) & (51, 1) (mid-season 11 onwards) is where UNKNOWN_97 was introduced
This would mean splitting out respawn.apex_legends11 to track the new lump's addition

Lump 0x0061 was added in Season 7

[snake-biscuits]

$ find "$apex_archive" -type f -name "*.0061.bsp_lump"

0061.bsp_lump files appear as far back as Season 7
My map archive is spotty pre-Steam release, so I can't exactly which season added the lump
Definitely some point post-season 3

No apex_legends branch split today

[snake-biscuits]

I'm missing maps from season4 - 6:

• [Apex Archive] Need maps from 2020 for tests & research #138

I do have some season5 maps, but I don't know which patches the maps came from

0x0061 could come from some time in season6