4B entity_count. 0 in empty files, 1 for single objects, N>1 in opkg.hob files
4B simple offset to vertices/faces - doesn't work all the time. Probably useless?

16B name
4B facegroups offset
4B always 0x7C 124
4B int 0x88, 0xA8
12B zero?
4B 94, 0xD4
4B 98, 0x100
4B 9C, 0x104
4B float:
    -bark_moon, cldcar: 1.0
    -sky, e_cor: 0.2 
    -wmvwing: 1.25
12B zero
5x4B floats
4B int / bark_moon, e_cor, towc: 0xA = 10
6x 4B float

2B number of facegroups? NOF
2B number of facegroups? NOF
facegoup definitions 
{
  offsets, names, floats
}  

4B 0xFFFFFFFF header end marker

NOF * facegroup/meshdef0 {
  4B int
  4B int
  4B int
  4B int
  4B int offset to meshdef1 + 4
  8B zero
  48B 3 * {
    4B float 1.0
    12B zero
  }
  4B int
  3 * 4B float
  3 * 4B float 1.0
  28B zero
}

NOF * facegroup/meshdef1 96B {
  4B int facedef end offset
  20B zero
  4B int vertices used
  8B zero
  4B int face def offset
  4B int vertex def offset
  52B zero
}
  
NOF * face definition
{
  8B zero
  4B int filepos + 4
  4B int face count FC
  FC * face block
  {
    4B int ?    
    1B int 46/49/4B
    1B int 51/71
    1B int 0C
    1B int block size / 4: A = 40B, 9 = 36, etc.
        if block size = 9, this is a triangle, else quad
    2B int zero?
    2B int texture/material index?
    4x 2B vertex indices, if triangle, the last index is zero. Vertex indices are relative to the face group
    x bytes until block size
  }
}

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