rerogue/doc/file_hob_spec.txt

HOB
{
  4B int : object count OF. 0 in empty files
  4B int : simple offset to vertices/faces - doesn't work all the time. Probably useless?
  array[OF] of Object
  array[OF] of Facegroup header 
  array[] of Facegroup/meshdef0 
  array[] of Facegroup/meshdef1
  array[] of Face block
  array[] of Vertices
}

Object [116B] 
{
  16B array of char : name
  4B int   : facegroups offset
  4B int   : object parts offset
  4B int   : facegroup header 2 offset
  12B zero
  4B int   : ? 94, 0xD4
  4B int   : ? 98, 0x100
  4B int   : ? 9C, 0x104
  4B float : ?
      -bark_moon, cldcar: 1.0
      -sky, e_cor: 0.2 
      -wmvwing: 1.25
  12B zero
  5x 4B float : ?
  4B int offset before 0xFFFFFFFF header end marker
  6x 4B float : ?
}

Object parts (Facegroup) header [variable length]
{
  2B int : number of facegroups/object parts NOF
  2B NX ?
  NOF * Facegroup/meshdef0 offset {
    4B int : ?
    4B int : facegroup/meshdef0 offset
  }
  2B int : NOF again
  2B NX ?  
  NX * offsets + zeros
  NOF * name {
    2B int           : facegroup number
    8B array of char : name
  }

  4B 0xFFFFFFFF header end marker
}

Facegroup/meshdef0 (fg/m0) [132B]
{
  4B int : offset to next fg/m0, 0 if there's no next, or in some other circumstances
  4B int : offset to prev?
  4B int : offset to beginning if this is not first fg/m0?
  4B int : offset to end if offset to next = 0
  4B int : offset to meshdef1 + 4
  8B zero
  48B 3 * {
    4B float : 1.0
    12B zero
  }
  4B int : ? 8 in atst, 0 in tief, 1,9,5 in atpt
  3 * 4B float
  3 * 4B float 1.0, 2.961700037E-02?
  4 * 4B float
  3 * 4B float - (relative) translation x/y/z?
}

Facegroup/meshdef1 [96B] 
{
  4B int : facedef end offset
  20B zero
  4B int : vertex count
  4B int ?
  4B zero
  4B int : Face block offset
  4B int : Vertex block offset
  52B zero
}
  
Face block [variable length]
{
  8B zero
  4B int : current file position + 4
  4B int : face count FC
  FC * Face : faces
}

Face
{
  4B int : face flags
      - bits 0, 1 unknown
      - if bit 2 is set, face has texture coordinates (uv-s)    
      - if bit 3 is set, the face is a quad, otherwise it's a triangle
      - if bit 4 is set, face has separate colors for each vertex
      - if bit 5 is set, face has color
      - if bit 6 is set, face has extra 8 bytes before vertex colors
      - bits 7-10 unknown. higher bits don't seem to be set
  1B int : ? 46/49/4B
  1B int : ? 51/71
  1B int : ? 0C
  1B int : face block size divided by 4
      - A = 40B, 9 = 36, etc.
  2B int : zero
  2B int : material index
  4x 2B vertex indices, relative to the face group. The last index is zero in triangle faces 
  if (face has extra 8 bytes) {
      8B extra bytes
  }
  if (face has color) {
      if (face has vertex colors) {
          3/4 * 4B : RGBA vertex color
      } else {    
          4B : RGBA color
      }
  }
  if (face has texture coordinates) {
      3/4 * {
          2B int : horizontal texture coord (multiply by 1/4096 to get 0..1 range)
          2B int : vertical texture coord
      }
  }
}

Vertices
{
  2B int X
  2B int Y
  2B int Z
  2B int ?
}