P3D File Format - ODOLV7

General

Legend

see Generic FileFormat Data Types

CompressedStructures

(potentially) compressed arrays are endemic to most blocks contained in a p3d.

CompressedStruct
{
  ulong  Count;
  <type> Array[Count];
};

if Count * sizeof(<type>) exceeds 1023 bytes the array is compressed. The resulting array will be expanded using lzh compression exactly as found in pbo's (for instance)

After de-compression, the Count remains the same because it is a count of the arraytype.

For uncompressed arrays (byte count < 1024) the Count and data are treated 'as is'.

Thus for various Array <types>

• ulong Array: > 255 // 1024 / sizeof(ulong)
• float thing[2]: > 127 // 1024 / 2*sizeof(float)
• SomeStructure: > // count * sizeof (SomeStructure) > 1023

Note that potentially compressed arrays in these structures only have an known output length. the decompressor therefore must work on infinite input length.

Odol7Stuct

ODOLV7
{
  StandardP3DHeader Header;
  LodStruct         Lods[Header.LodCount];
  ModelInfo         ModelInfo;
};

StandardP3DHeader

StandardP3DHeader
{
  char      Signature[4];      //"ODOL" (vs MLOD eg)
  ulong     Version;           // 7
  ulong     LodCount;          // at least one
}

LodStruct

LodStruct
{
 VertexTable    VertexTable;
 float          UnknownFloat1;
 float          UnknownFloat2;
 XYZTriplet     MinPos;
 XYZTriplet     MaxPos;
 XYZTriplet     AutoCenterPos;
 float          UnknownFloat3;
 Textures       Textures;
 LodEdges       LodEdges;         
 ulong          NoOfFaces;
 ulong          OffsetToLodSections;
 LodFace        LodFaces[NoOfFaces];               // ie polygons
 ulong          nSections;
 LODSection     LODSections[nSections];
 ulong          nNamedSelections;
 NamedSelection NamedSelections[nNamedSelections];
 ulong          nTokens;
 NamedProperty  NamedProperties[nTokens];
 ulong          nFrames;
 Frame          Frames[nFrames]; 
 ulong          IconColor;
 ulong          SelectedColor;
 ulong          Unknown;
 ulong          nProxies;
 LodProxy       LodProxies[nProxies];
};

VertexTable

 struct
 { 
   ulong       Count;              
   ulong       PointFlags[Count];  // compressed. see P3D Point and Face Flags
   ulong       Count;             
   UVPair      UV1[Count];         // compressed 
   ulong       Count;              
   XYZTriplet  Points[Count];      // UNcompressed
   ulong       Count;             
   XYZTriplet  Normals[Count];     // UNcompressed
 }

• Count is the same value for all four tables.

Textures

 struct
 {
  ulong  Count;
  asciiz Textures[...];          // "data/1.paa\0data/2.paa\0"...
 }

Count corresponds to the number of concatenated strings. It is required, since, architecturally at least, one of more of the asciiz strings could be null.

NamedProperty

 struct
 {
    Asciiz Property;// "noshadow" = "1" eg
    Asciiz Value;
 }

Related Page(s)

LZ in ODOL

see Compressed LZSS File Format

Model File Formats