Unknown Apex Legends Lumps

[snake-biscuits]

Deduced Unknowns

• UNKNOWN_37 (VIS SpecialLumpClass?)
• UNKNOWN_38 (CSM SpecialLumpClass?)
• UNKNOWN_39 (VIS SpecialLumpClass?)
• UNKNOWN_43 CUBEMAPS_AMBIENT_RCP
• UNKNOWN_44 WaterBody
• UNKNOWN_45 WaterCenter
• UNKNOWN_46 WaterVertex
• UNKNOWN_47 WaterIndex
• UNKNOWN_48 WaveData
• UNKNOWN_57
• UNKNOWN_97 LIGHTMAP_DATA_UNKNOWN

Theories / Summaries

37..39

Could be CSM & VIS related
Going by other lumps loaded around them in season3's .exe

43

CUBEMAPS_AMBIENT_RCP
A memory page for holding a txtx .rpak asset

44..48

WaterBodies system
Introduced in Season 11 w/ Storm Point for the ocean shader

• Apex Legends Water Bodies system #166

57

Introduced in Season 21 (first appearance of rBSP v52.1)
Cannot find .bsp_lump in .rpak

97

Could be lightmap related

• `UNKNOWN_97` might be RTL lightmap data #122

[snake-biscuits]

>>> import bsp_tool, os, fnmatch
>>> sd = "E:/Mod/ApexLegends/season17/9may23"
>>> md = os.path.join(sd, "maps")
>>> dd = os.path.join(sd, "depot/r5-170/game/r2/maps")
>>> maps = {m[:-4]: bsp_tool.load_bsp(os.path.join(md, m)) for m in fnmatch.filter(os.listdir(md), "*.bsp")}
>>> maps.update({f"depot/{m[:-4]}": bsp_tool.load_bsp(os.path.join(dd, m)) for m in fnmatch.filter(os.listdir(dd), "*.bsp")})
>>> {b.bsp_version for b in maps.values()}
{(51, 1)}  # since season 13
>>> {L for b in maps.values() for L, h in b.headers.items() if L.startswith("UNUSED_") and h.length != 0}
{'UNUSED_44', 'UNUSED_45', 'UNUSED_46', 'UNUSED_47', 'UNUSED_48'}

[snake-biscuits]

>>> from typing import List
>>> from tests import maplist
>>> def check(season: int) -> List[str]:
...     k = f"ApexLegends/season{season}"
...     for md in maplist.extracted_dirs[k]:
...             fmd = os.path.join("E:/Mod", k, md)
...             maps = {m[:-4]: bsp_tool.load_bsp(os.path.join(fmd, m)) for m in fnmatch.filter(os.listdir(fmd), "*.bsp")}
...             print(md)
...             {print("!", m) for m, b in maps.items() if len({L for L, h in b.headers.items() if L.startswith("UNUSED_") and h.length != 0}) != 0}
... 

Season 11

>>> check(11)
2nov21/maps
2nov21/depot/r5-110/game/r2/maps
6nov21/maps
! mp_rr_tropic_island
6nov21/depot/r5-110/game/r2/maps
! mp_rr_tropic_island
19nov21/maps
! mp_rr_arena_habitat
! mp_rr_tropic_island
19nov21/depot/r5-110/game/r2/maps
! mp_rr_tropic_island
19nov21/depot/r5-111/game/r2/maps
! mp_rr_arena_habitat
! mp_rr_tropic_island

Season 12

>>> check(12)
9feb22/maps
! mp_rr_arena_habitat
! mp_rr_tropic_island
9feb22/depot/r5-120/game/r2/maps
! mp_rr_arena_habitat
! mp_rr_tropic_island
29march22/maps
! mp_rr_arena_habitat
! mp_rr_canyonlands_staging
! mp_rr_tropic_island
29march22/depot/r5-120/game/r2/maps
! mp_rr_arena_habitat
! mp_rr_tropic_island
29march22/depot/r5-121/game/r2/maps
! mp_rr_arena_habitat
! mp_rr_canyonlands_staging
! mp_rr_tropic_island

Firing Range (mp_rr_canyonlands_staging) uses some of these lumps in both Season 12 & Season 13

[snake-biscuits]

Season 11 is also when the move to v49.1 / v50.1 happened (.bsp_lump only lumps)
There were some v49 depot maps, which is odd because Season 10 has just introduced v50
Also, some Season 11 folders don't use UNKNOWN_48

Though IIRC Storm Point had been in development the longest of the 4 BR mode maps

[snake-biscuits]

Now that we know 44..48 is the WaterBodies system
I wonder if the season12 & 13 canyonlands_staging used WaterBodies

We should establish a timeline of when each lump was introduced
A job for the Apex Archive!

[snake-biscuits]

According to git blame we've been tracking UNKNOWN_97 since the 30th of June 2021

My Apex Legends archives are a little patchy in places, so nailing down format changes could get tricky
I have almost nothing before Season 5, besides the R5R S3 builds

For some seasons I only grabbed the maps with .vpks that were touched that patch
Can probably refer to SteamDB to check exactly when each map is updated

NOTE: .vpk can be updated without touching maps

[snake-biscuits]

Digging further in #122, I found that UNKNOWN_97 probably predates the Steam release of Apex

[snake-biscuits]

To find out when LIGHTMAP_DATA_UNKNOWN was added we'll need to fulfil:

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

[snake-biscuits]

Looking at which lumps are streamed from .rpaks in Season 18 (#121) might shed some light
Most streamed lumps seem to be linked to rendering
Meanwhile non-streamed lumps hold physics & top-level metadata (ObjReferences, LevelInfo etc.)

[snake-biscuits]

While looking into #165 @r-ex identified multiple lump names w/ ida

Old Name	Hex	New Name	Size Check
UNUSED_21	0015	HEIGHTFIELDS	40
UNUSED_22	0016	HEIGHTFIELD_SAMPLES	2
UNKNOWN_37	0025	UNKNOWN_37	N/A
UNKNOWN_38	0026	UNKNOWN_38	N/A
UNKNOWN_39	0027	UNKNOWN_39	N/A
UNKNOWN_43	002B	CUBEMAPS_AMBIENT_RCP	N/A
UNKNOWN_44	002C	WATER_BODY	80
UNKNOWN_45	002D	UNKNOWN_45	24
UNKNOWN_46	002E	WATER_BODY_VERTICES	24
UNKNOWN_47	002F	WATER_BODY_INDICES	2
UNKNOWN_48	0030	WAVE_DATA	4

[snake-biscuits]

44..48 error messages mention Mod_LoadDynamicWater

[snake-biscuits]

002B CUBEMAPS_AMBIENT_RCP is variable size
Always null bytes

I joked that it might be like LIGHTMAP_DATA_RTL_PAGE & turns out that's accurate
The lumps sizes matches the txtx .rpak assets for the map
texture_extension/%s%s/cubemaps_hdr/cubemap_ambients.rpak

So, for now we're going to say RCP stands for Rpak Cursed Page

[snake-biscuits]

Mostly have the WaterBodies system cracked now:

• Apex Legends Water Bodies system #166