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;
}