From Valve Developer Community

The plan is to break out this stuff when it's finished. --Beeswax 19:08, 1 May 2008 (PDT)

Compiling a Model

probable destination for this section is an introduction to Compiling models for Source. 3rd party MDL compilers often provide a different GUI to the QC file than StudioMDL, so a checklist of "things you should already have done" would be relevant to all MDL compiler docs. It includes model anatomy/glossary definitions for #REDIRECTs ?

Reference.smd

• The Reference.smd is traditionally named "modelname_ref.smd".
• It defines the model's Reference (http://en.wikipedia.org/wiki/Frame_of_reference) Skeleton and its "default" 3D Rendering Geometry:
  • The Reference Skeleton is the key for all of the model's geometry: vertex data for the render mesh, sub meshes, collisionmodel, hitboxset, attachments, animations, gibs, etc. all reference the skeleton.
  • The Reference Mesh is the "main body" (as opposed to $bodygroup sub-meshes) of the Render Model. The Reference Mesh's Skinning data also defines the filename(s) of the model's Default Skin(s).
• Notably, the reference.smd does not contain the model's
  • Physics geometry (collision & hitboxes)
  • Skin files
  • LOD meshes & skins
  • Optional meshes & skins
  • Animations
  • Game settings (QC /StudioMDL parameters)

Tip: See SMD file format for exactly how this data is stored in each "Studio Model Data" file.

Submesh.smd

• "submeshname_sub1.smd", "modelname_ref_sub1.smd" or "modelname_hat_ref.smd".
• defines a rendered submesh which may be added to the default mesh via $bodygroups. Submeshes cannot be included in the reference.smd.
• includes: ref-skeleton, defines: mesh (ie: skinname, uvmap, envelope & weightmap data)
• submesh.smd must be enveloped to the ref-skeleton ...

LOD.smd

• "lod1_modelname_ref.smd", "lod1_modelname_sub1.smd".
• LOD Models are simplified versions of renderable meshes. each requires its own smd, and are compiled into VVD/VTX of main model via the $lod configuration.
• the convention is to prefix the modelname "lod#_". The ref and sub.smds are effectively lod0_modelname_ref.smd, lod0_modelname_sub.smd,
• includes: ref-skeleton, defines: mesh geometry (ie: coords, smoothing, skinname, uvmap, envelope & weightmap data)

Physics.smd

• The Physics.smd is traditionally named "bodymeshname_phy.smd". _physmodel.smd or _physbox.smd
• defines the hull geometry, envelope and smoothing group data for the collisionmodel. incl ref-skeleton.
• includes the ref-skeleton and defines: hull geometry(s) (ie: vertex coords, normals, & envelope data)
  • Because hulls are rigid and not rendered, they don't use any UVmap or weightmap data.
  • Each hull must be a convex shape ie somewhere between a sphere and a box. Overlapping/intersecting multiple hulls are used to create ($concave) models.
  • Rigid collisionmodels ($collisionmodel) envelope all hulls to the same bone.
  • Jointed collisionmodels ($collisionjoints) envelope some hulls to different bones.

Hitbox.smd

• confirm: not compiled by StudioMDL, but opened in text editor for hitbox vertex coordinates?
• not rendered, simple collision = simple box geometry

Animation.smd

• Each Animation.smd is traditionally named "sequencename.smd".
• includes the ref-skeleton and defines a keyframed sequence of skeletal poses.
• $sequence "idle" "modelname_idle.smd"
• $sequence "ragdoll" "ragdoll.smd" ACT_DIERAGDOLL 1 fps 30.00
• $includemodel includes an AnimationLibrary.mdl