Research: backpack capacity / special slots + missing trait descriptions

Date: 2026-06-12. Probe file: tests/AbioticEditor.Tests/BackpackTraitProbeTests.cs (11 facts, all passing against the live install + Cascade fixtures + the Chrissie save under Saved/SaveGames/.../Worlds/Chrissie).

TASK 1 - Backpack capacity and special slots

Where capacity lives

ItemTable_Global row -> EquipmentData_100_... struct -> ContainerCapacity_20_DC743D864AC6607638E3D2B6D044F42D (IntProperty). Companion fields in the same struct: IsContainer_13_... (True for every backpack), ContainerWeightReduction_37_... (the pack's carry-weight discount, 0–0.42), and EquipSlot_5_... = E_InventorySlotType::NewEnumerator7 (= EquipmentSlot_Backpack per the enum's DisplayNameMap). There is no NumberOfExtraSlots-style column; capacity is the single number.

E_InventorySlotType DisplayNameMap (from Blueprints/Data/E_InventorySlotType): 0=Hotbar, 1=InventoryBackpack, 2=EquipmentSlots_All, 14(=3)=EquipmentSlot_Torso, 5(=4)=Head, 6(=5)=Legs, 7(=6)=Backpack, 12(=7)=Arms, 13(=8)=Suit, 15(=9)=Headlamp, 16(=10)=Trinket, 17(=11)=Wristwatch, 18(=12)=Hacker, 19(=13)=Shield, 20(=14)=Trinket2, 21(=15)=Companion (NewEnumeratorN = display order ≠ value).

Per-backpack table (all 20 backpack_* rows in ItemTable_Global)

Row id	Display name	Capacity (total slots)	Weight red.	Special slots (0-based Inventory_ index)
backpack_makeshift	Makeshift Backpack	15	10%	-
backpack_small	Basic Backpack	18	15%	-
backpack_votv_small	Dunkeltaler Backpack	18	15%	-
backpack_radio	Radio Pack	21	12%	-
backpack_security	Security Pack	21	14%	-
backpack_medium	Military Pack	24	20%	-
backpack_chieftain	Chieftain Pack	24	20%	-
backpack_heavy	Giant's Pack	30	30%	-
backpack_hikingpack	Hiking Pack	30	42%	-
backpack_snow	Alpine Pack	30	33%	-
backpack_rat	Rat Pack	30	0%	-
backpack_jetpack	Jetpack	30	28%	-
backpack_longjumppack	Long Jump Pack	30	20%	-
backpack_large	Research Pack	30	22%	0=Shielded(rad), 1=Refrigerated
backpack_research_U1a	Field Sample Pack	30	22%	0,2=Shielded(rad), 1=Warmer(heated)
backpack_research_U1b	Cold Storage Pack	30	22%	0,2=Refrigerated, 1=Freezer
backpack_huge	Voidpack	36	25%	- (description is just "huge storage capacity")
backpack_voidpack_U1a	Crystalline Pack	36	27%	- (recharges battery/laser items - a behavior, not slots)
backpack_voidpack_U1b	Glitch Pack	36	27%	1=Freezer, 6=Shielded, 8=Refrigerated, 13=Warmer
backpack_dimension	Pocket Dimension	42	30%	-

The "Voidpack" the user remembers is row id backpack_huge (display name "Voidpack"); there is no backpack_void row. The cold/warm/rad packs are the Research-pack family (backpack_large, backpack_research_U1a/b) plus the Glitch Pack.

Where special slots live (NOT in ItemTable_Global)

Chain: DT_ItemCosmetics (Blueprints/DataTables/DT_ItemCosmetics, 298 rows, row name = item id) -> column DataAsset_51_083C190445D5CD182B8E95B43BD31D1F (ObjectProperty) -> an InventoryData_Parent_C DataAsset under Blueprints/DataAssets/Inventory/:

DataAsset	Used by	RefrigeratedSlots	FreezerSlots	ShieldedSlots	WarmerSlots
BackpackData_Research	backpack_large	[1]	-	[0]	-
BackpackData_ColdStorage	backpack_research_U1b	[0,2]	[1]	-	-
BackpackData_FieldSample	backpack_research_U1a	-	-	[0,2]	[1]
BackpackData_Glitch	backpack_voidpack_U1b	[8]	[1]	[6]	[13]

Each asset also carries SlotAppearanceOverrides (map: slot index -> E_InventorySlotAppearance: NewEnumerator5=freezer, 6=refrigerated, 7=shielded, 9=warmer skin). These are the only four such assets in the game; every other backpack has DataAsset = null in its cosmetics row.

So special slots are specific 0-based indices into the player's Inventory_ array - at the FRONT (0/1/2) for the research packs, scattered for the Glitch Pack - never "the last N slots". (W_Inventory_PlayerBackpack reads SlotAppearanceOverrides/SlotTypeToIndex from this asset at runtime.)

Save-side behaviour (4 Cascade fixture players + Chrissie)

Inventory_ length tracks the equipped backpack exactly - it is not a fixed array with spare tail:

Save	Equip[3] (backpack)	Inventory_ length	Capacity from table
Cascade ...479	backpack_longjumppack	30	30
Cascade ...890	backpack_huge	36	36
Cascade ...108	backpack_medium	24	24
Cascade ...042	backpack_research_U1b	30	30
Chrissie ...479	backpack_large	30	30

HotbarInventory_ was 8 and EquipmentInventory_ 13 in every save (Fanny Pack trait claims +2 hotbar; no sampled save lacks it, so the no-trait base is unverified). Unused slots hold the "Empty" sentinel (some patched saves also show None). No save had a backpack-less character, so the length with Equip[3] = Empty is unverified (expect the game to shrink/resize on (un)equip).

What the editor should do

• Usable slots = look up Equipment[3].ItemId in ItemCatalog -> EquipmentData_ -> ContainerCapacity_ (prefix-match both names). The save's Inventory_ length should already equal it.
• When the editor changes the equipped backpack, resize Inventory_ to the new capacity (pad with "Empty" slots / truncate trailing slots) so the array matches what the game writes.
• Special-slot badges: hardcode (or load from the 4 BackpackData assets via DT_ItemCosmetics) the table above; annotate inventory cells whose index appears in the relevant array when the matching pack is equipped.
• ItemCatalogEntry currently doesn't surface ContainerCapacity - add it (read from the EquipmentData_ sub-struct in ItemCatalog.BuildEntry).

TASK 2 - Missing trait descriptions in CDT_AllTraits

TraitCatalog.LoadDetailsFrom is not buggy - no hash-suffix/prefix mismatch this time. The exact columns are TraitName_7_E2887506467F3946582B49A4AD6F3CE7, TraitDescription_8_53B3D8DA4A2E41A6FF24038C38E5F06D (both TextProperty/FText), PointCost_27_1F822A4E48D40334AD58858A1AB4F9F3 (Int) and they're read correctly.

The empty descriptions are genuinely empty in the game data: the FText has HistoryType=None (no string at all). Exactly 9 of the 50 rows are affected, and they are precisely the cut/disabled traits - all have AvailableOnStart_29_... = False and placeholder TraitIcon = icon_missing:

Trait_Agoraphobic, Trait_Fumbler, Trait_Claustrophobic, Trait_Clumsy (icon ok), Trait_Hemophobic (icon ok), Trait_Dyslexia, Trait_RestlessSleeper, Trait_Smoker, Trait_Unlucky

These never appear in the in-game character creator. Their buff rows in Blueprints/DataTables/BuffsDebuffs/DT_BuffsDebuffs (e.g. Debuff_Trait_Dyslexia) were checked as a fallback description source - also empty (DisplayDescription/TooltipText_Apply blank, icon_missing); trait buffs are hidden HUD-less buffs, even for implemented traits. There is no alternate text anywhere.

'Forbidden Diet' (Trait_Cannibal) genuinely has PointCost = 0 - it's a world-acquired trait (eating human flesh), not a creation pick, so "no points value" is correct data; same for Trait_SunDisk (0) and the special rows PhD_Iron / Trait_FormerGuard / Trait_EasilyStartled (AvailableOnStart=False but fully described - they're granted by game events/modes, not creator picks).

Exact fix

1. In TraitCatalog.LoadDetailsFrom, also read the AvailableOnStart_ prefix (BoolProperty) into TraitDetail (e.g. bool AvailableOnStart).
2. UI: for traits with an empty/null description, show a stock line like "No in-game description (unused/disabled trait)" when AvailableOnStart is false - or filter such rows out of any "pick a trait" list entirely (keep them visible read-only if a save already has one).
3. Show 0 PTS (or hide the badge) for 0-cost world-obtained traits instead of treating 0 as missing.
4. Optionally treat empty-string descriptions as null: FText with HistoryType=None stringifies to "" via GenericValue.ToString(), so coerce description = string.IsNullOrWhiteSpace(s) ? null : s.

Probe inventory (BackpackTraitProbeTests)

• Dump_BackpackRows_ItemTableGlobal - all "pack" row ids + full column dump of backpack rows.
• Dump_SlotRelatedColumns_AcrossItemTable - deduped flattened column-name census of ItemTable_Global.
• Dump_PlayerInventoryLengths_VsEquippedBackpack - the save-side table above.
• Dump_BackpackSpecialSlotSources - asset census + Gear_Backpack BP exports (BPs hold no slot data).
• Dump_BackpackDataAssets_AndSlotTypeEnum - the 4 BackpackData assets + E_InventorySlotType DisplayNameMap.
• Scan_WhoReferencesBackpackData - raw byte scan of all 3227 Blueprints packages -> only DT_ItemCosmetics.
• Dump_ItemCosmetics_BackpackRows - the DataAsset_51_... wiring rows.
• Scan_GearBackpackHuge_ForSlotNames - confirms slot arrays live in the data assets, widget reads them.
• Dump_AllTraitsRows_FullColumns / Dump_ProblemTraitRows_DescriptionColumns - all 50 trait rows with FText internals (HistoryType) proving the data is empty.
• Dump_BuffRows_ForEmptyDescriptionTraits - DT_BuffsDebuffs fallback check (negative).