rerogue/doc/file_hob_spec.txt

HOB
{
  4B object count OF. 0 in empty files
  4B simple offset to vertices/faces - doesn't work all the time. Probably useless?
  array[OF] of object header
  array[OF] of facegroup header 
  ..
  array[] of vertices
}

OF * object header [116B] 
{
  16B name
  4B int facegroups offset
  4B int facegroup header 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
  5x4B floats ?
  4B int offset before 0xFFFFFFFF header end marker
  6x 4B float ?
}

OF * facegroup header [varlen]
{
  2B number of facegroups NOF
  2B NX ?
  NOF * facegroup/meshdef0 offset {
    4B int ?
    4B int facegroup/meshdef0 offset
  }
  2B NOF again
  2B NX ?  
  NX * offsets + zeros
  NOF * name {
    2B facegroup number
    8B char
  }

  4B 0xFFFFFFFF header end marker
}

NOF * 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?
}

NOF * facegroup/meshdef1 [96B] 
{
  4B int facedef end offset
  20B zero
  4B int vertices used
  4B int ?
  4B zero
  4B int face def offset
  4B int vertex def offset
  52B zero
}
  
NOF * face block
{
  8B zero
  4B int filepos + 4
  4B int face count FC
  FC * 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
            2B int vertical texture coord
        }
    }
  }
}

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