Data structures¶

This section documents the mdl file format itself, structure by structure, as ValveMDL understands it.

What is supported¶

ValveMDL is evidence driven: a structure is documented here once it has been read out of real files and cross-checked against the Source SDK, and not before. Gaps are left as gaps rather than guessed at.

Documented means the structure is defined here and checked against the SDK. Loaded means ValveMDL follows the offsets to it and hands it to you.

Structure	Documented	Loaded
`studiohdr_t`	yes	`mdl.header`
`studiohdr2_t`	yes	`mdl.header2`
`mstudiobone_t`	yes	`mdl.bones`, names and surfaceprops resolved
`mstudiobonecontroller_t`	yes	`mdl.bonecontrollers`
`mstudioaxisinterpbone_t`	yes	`bone.procedural`
`mstudioquatinterpbone_t`	yes	`bone.procedural`
`mstudioaimatbone_t`	yes	`bone.procedural`
`mstudiojigglebone_t`	yes	`bone.procedural`
`vertexFileHeader_t`	yes	`mdl.vvd.header`
`FileHeader_t` (vtx)	yes	`mdl.vtx.header`
`mstudiovertex_t`	yes	`mdl.vvd.vertices`
`mstudiotexture_t`	yes	`mdl.textures`, names resolved
cdtextures (search paths)	yes	`mdl.cdtextures`
Skin replacement table	yes	`mdl.skins`
`mstudioanimdesc_t`	yes	`mdl.animations`
`mstudioseqdesc_t`	yes	`mdl.sequences`
`mstudioanim_t`	yes	`animation.nodes`, extents measured
`mstudioikchain_t`	yes	`mdl.ikchains`, with `.links`
`mstudioikrule_t`	yes	`animation.ikrules`
`mstudioevent_t`	yes	`sequence.events`
`mstudioflexdesc_t`	yes	`mdl.flexdescs`
`mstudioflexcontroller_t`	yes	`mdl.flexcontrollers`
`mstudioflexrule_t`	yes	`mdl.flexrules`, with `.ops`
`mstudioflex_t`	yes	`mesh.flexes`, with `.vertanims`
`mstudioeyeball_t`	yes	`model.eyeballs`
`mstudiolinearbone_t`	yes	`mdl.linearbones`
`mstudiobodyparts_t`	yes	`mdl.bodyparts`, names resolved
`mstudiomodel_t`	yes	`mdl.models`, or `bodypart.models`
`mstudiomesh_t`	yes	`mdl.meshes`, or `model.meshes`
`mstudiohitboxset_t`	yes	`mdl.hitboxsets`, with `.hitboxes`
`mstudiobbox_t`	yes	`hitboxset.hitboxes`
`mstudioattachment_t`	yes	`mdl.attachments`
`mstudioposeparamdesc_t`	yes	`mdl.poseparameters`
`mstudiomodelgroup_t`	yes	`mdl.includemodels`
`mstudiomouth_t`	yes	not yet
`mstudioanimblock_t`	yes	not yet
Vertex and tangent pools	yes	`mdl.vvd.vertices` / `.tangents`
Vvd fixup table	yes	`mdl.vvd.fixups`, replayed by `mesh_vertices()`
Vtx mesh tree	yes	`mdl.vtx.bodyparts`

Versions¶

Team Fortress 2 ships mdl versions 44, 45, 46, 47 and 48 – five variants of the same format, in the same game. Version 48 accounts for about 91% of them. studiohdr_t itself is unchanged across that whole range; the version differences live in how the structures it points at are interpreted.