A Kaitai Struct for DBPF Geom Entries

simgeom.ksy

meta:
  id: geom
  file-extension: geom
  endian: le
  imports:
    - path/to/mtnf.ksy
seq:
  - id: header
    type: header
  - id: shader
    type: shader
  - id: merge_group
    type: u4
  - id: sort_order
    type: u4
  - id: vertex_collection
    type: vertex_collection
  - id: body_count
    type: u4
  - id: bodies
    type: body
    repeat: expr
    repeat-expr: body_count
  - id: skin_controller_index
    type: u4
  - id: bone_count
    type: u4
  - id: bones
    type: u4
    repeat: expr
    repeat-expr: bone_count
    doc: 32-bit hash of the bone name
  # insert TGI block list here
types:
  header:
    seq:
      - id: magic
        contents: 'GEOM'
      - id: version 
        type: u4
        valid:
          any-of: [0x00000005, 0x0000000C]
        doc: "see [Sims4Tools \\> GEOM.cs#L129](https://github.com/s4ptacle/Sims4Tools/blob/fff19365a12711879bad26481a393a6fbc62c465/s4pi%20Wrappers/MeshChunks/GEOM.cs#L129C67-L129C77)"
      - id: tgi_offset
        type: u4
        doc: Offset to the reference data from this object's offset -- may also be from this sequence entry's offset
      - id: tgi_size
        type: u4
  shader:
    seq:
      - id: id
        type: u4
        doc: "also referred to as 'EmbeddedID' in some tools. see [simswiki \> Sims 3 \> GEOM](https://simswiki.info/wiki.php?title=Sims_3:0x015A1849)"
      - id: size
        type: u4
        if: id != 0
      - id: mtnf            # Requires definition
        type: mtnf 
        if: id != 0
  vertex_collection_count:
    seq:
      - id: verteces
        type: u4
      - id: formats 
        type: u4
  vertex_collection:
    seq:
      - id: count
        type: vertex_collection_count
      - id: formats 
        type: vertex_format
        repeat: expr
        repeat-expr: count.formats
      - id: verteces
        type: vertex
        repeat: expr
        repeat-expr: count.verteces
  vertex_format:
    seq:
      - id: type
        type: u4
        valid:
          any-of: [1,2,3,4,5,6,7,10]
        doc: |
          1. Position
          2. Normal
          3. UV
          4. Bone Assignment
          5. Weights
          6. Tangent Normal
          7. TagVal
          10: VertexID
      - id: subtype 
        type: u4
        valid:
          min: 1
          max: 4
      - id: size
        type: u1
  vertex:
    seq:
      - id: elements
        type: vertex_element(_parent.formats[_index].type)
        repeat: expr
        repeat-expr: _parent.count.formats
  vertex_element:
    params:
      - id: index
        type: u4
    seq:
      - id: content
        type:
          switch-on: index
          cases:
            1: vertex_element_position
            2: vertex_element_normal
            3: vertex_element_uv
            4: vertex_element_bone_assignment
            5: vertex_element_weights
            6: vertex_element_tangent_normal
            7: vertex_element_tag_val
            10: vertex_element_vertex_id
  vertex_element_position:
    seq:
      - id: x
        type: f4
      - id: y
        type: f4
      - id: z
        type: f4
  vertex_element_normal:
    seq:
      - id: x
        type: f4
      - id: y
        type: f4
      - id: z
        type: f4
  vertex_element_uv:
    seq:
      - id: u
        type: f4
      - id: v
        type: f4
  vertex_element_bone_assignment:
    seq:
      - id: bone
        type: u32
  vertex_element_weights:
    seq:
      - id: weight
        type: f4
        repeat: expr
        repeat-expr: 4
  vertex_element_tangent_normal:
    seq:
      - id: x
        type: f4
      - id: y
        type: f4
      - id: z
        type: f4
  vertex_element_tag_val:
    seq:
      - id: value
        type: u32
  vertex_element_vertex_id:
    seq:
      - id: id
        type: u32
  body:
    seq:
      - id: face_size
        type: u1
      - id: face_count
        type: u4
      - id: faces
        size: face_size
        repeat: expr
        repeat-expr: face_count