WMO group chunks¶
The typed wire structs of a WMO group file — geometry, render batches, liquid
grids and per-group lighting — plus the flag enums their fields carry. A struct
that changed across client versions (the render batch WMOBatch, the group
header WMOGroupHeader) documents once: one merged member walk under its
generic ⟨version⟩ name, each member badged with the expansion range it belongs
to (a badge-less member is identical in every version). Wire integer fields show
their on-disk width.
Bases: IntFlag
Per-triangle flag bits (MOPY and MPY2).
Attributes:
| Name | Description |
|---|---|
Transition |
A transition face, blending exterior and interior lighting. |
NoCamCollide |
The camera does not collide with this face. |
Detail |
A detail face. |
Collision |
Collision-only (also turns off water ripples). |
Hint |
A hint face. |
Render |
A rendered face. |
CullObjects |
Enables game-object culling against this face. |
CollideHit |
Collides with projectiles/hit tests. |
Per-triangle material info v2 (MPY2, 10.0+): the MOPY replacement with 16-bit fields for multiple-material support.
WMOBatch⟨version⟩¶
A MOBA render batch, abstract over the client version. Construct a concrete version with WMOBatch.for_version(expansion).
property
writable
¶
16-bit material id; used when flags has 0x2.
One MORB entry (Cata+): a triangle-strip override of the matching MOBA batch's start and count. Same count as MOBA; ignored unless the client renders strips.
One MOBS shadow batch (Cata+): the shadow-pass counterpart of a MOBA render batch.
One MOBN BSP node for collision: a split plane or a leaf referencing faces through MOBR.
Bases: IntFlag
Group flag bits (MOGP and MOGI flags).
Attributes:
| Name | Description |
|---|---|
HasBsp |
Has a collision BSP tree (MOBN/MOBR). |
HasLightMap |
Has a light map (v14 legacy; unused since vanilla). |
HasVertexColors |
Has vertex colors (MOCV). |
Exterior |
Outdoor group (SMOGroup::EXTERIOR). |
ExteriorLit |
Use exterior lighting; no local diffuse. |
Unreachable |
Unreachable (SMOGroup::UNREACHABLE). |
ShowExteriorSky |
Show the exterior sky inside this interior group. |
HasLights |
Has light references (MOLR). |
Lod |
Legion+: an LOD group. Pre-Cata: marked the unused MPB* chunks. |
HasDoodads |
Has doodad references (MODR). |
HasLiquid |
Has liquid (MLIQ), or an implicitly full volume. |
Interior |
Indoor group (SMOGroup::INTERIOR). |
QueryMountAllowed |
Pre-WotLK: whether mount queries are allowed. |
AlwaysDraw |
Always draw (clears exterior after group creation). |
HasTriangleStrips |
Has triangle-strip data (MORI/MORB). |
ShowSkybox |
Show the skybox; unset automatically when MOSB is absent. |
Ocean |
The liquid is ocean, not water (LiquidType handling). |
MountAllowed |
Mounting is allowed in this group. |
HasTwoMocv |
Has a second MOCV layer; only its alpha is used. |
HasTwoMotv |
Has two MOTV texcoord sets (SMOGroup::TVERTS2). |
Antiportal |
An antiportal occluder group (SMOGroup::ANTIPORTAL). |
ExteriorCull |
Exterior culling (SMOGroup::EXTERIOR_CULL, Legion+). |
HasThreeMotv |
Has three MOTV texcoord sets, e.g. for shader 18. |
Bases: IntFlag
Extended group flag bits (MOGP.flags2 and MGI2).
Attributes:
| Name | Description |
|---|---|
CanCutTerrain |
Has terrain-cutting portal planes (MOPL, WoD+). |
IsSplitGroupParent |
Parent of a split group (9.2+). |
IsSplitGroupChild |
Child of a split group (9.2+). |
AttachmentMesh |
An attachment mesh (9.2 - 11.0). |
WMOGroupHeader⟨version⟩¶
A MOGP group header, abstract over the client version. Construct a concrete version with WMOGroupHeader.for_version(expansion).
property
writable
¶
Byte offset of the descriptive name in MOGN.
property
writable
¶
Group liquid type; interpretation depends on the root use_liquid_type_dbc_id flag.
property
writable
¶
Unused up to 9.1.5 (becomes the split-group indices in 9.2+).
property
writable
¶
Parent split group, or the first child (9.2+ split groups).
property
writable
¶
Next sibling in the split-group chain.
One light-set range (8.1+): a (first, count) window into the group's spot lights (MLSS -> MOLS), point lights (MLSP -> MOLP) or point-light animations (MLSK -> MOP2).
The magma/slime reading of an MLIQ vertex (8 bytes): two int16 texture coordinates sharing the layout with the water reading (SMOLVert). Obtain one with SMOLVert.as_magma(); which reading is correct is set by the group's liquid type, not stored per vertex.
One MLIQ liquid vertex (8 bytes). The byte layout is fixed but its interpretation depends on the group's liquid type: water/ocean read the named flow fields; magma/slime reinterpret the first four bytes as two int16 texture coordinates (s, t) — use as_magma()/set_magma() for that reading. Both are 8 bytes, so round-trip is layout-agnostic — pick the reading from the group's liquid type.
property
writable
¶
Water: flow velocity 2. Magma/slime: high byte of int16 s.
property
writable
¶
Water: flow-1 percentage. Magma/slime: low byte of int16 t.
property
writable
¶
Water: filler. Magma/slime: high byte of int16 t.
One MLIQ tile flag byte: bits 0-5 the legacy liquid type, bit 6 fishable, bit 7 shared with an adjacent group.
property
writable
¶
Packed liquid-type / fishable / shared flags.
Structured MLIQ liquid data: a vertex grid and a tile-flag grid with a base position and material id. The on-disk header is 30 bytes (the uint16 material id sits directly after a 12-byte vector, so the header is read field-by-field, not memcpy'd) followed by verts_dim.xverts_dim.y vertices and tiles_dim.xtiles_dim.y tile bytes.