P3D File Format - ODOLV7
Legend
see Generic FileFormat Data Types
Intro
CompressedStruct
ODOL7 uses (potentially) compressed arrays.
This obviously slows the engine down during loading. At the time of CWC development, game file sizes were important.
(potentially) compressed arrays are contained in a CompressedStruct
CompressedStructs are endemic to most blocks contained in the 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.
see example decompression at end of document
Odol7Stuct
ODOLV7
{
StandardP3DHeader Header;
LodStruct Lods[Header.LodCount];
struct ModelInfo; //see P3D Model Info
};
StandardP3DHeader
StandardP3DHeader
{
char Signature[4]; //"ODOL"
ulong Version; // 7
ulong LodCount; // at least one
}
LodStruct
LodStruct
{
VertexTable VertexTable;
UVPair UnknownUV; // just a guess
XYZTriplet MinPos;
XYZTriplet MaxPos;
XYZTriplet AutoCenterPos;
float UnknownFloat;
Textures Textures;
LodEdges LodEdges; // see P3D Lod Edges
ulong NoOfFaces;
ulong OffsetToLodSections;
LodFace LodFaces[NoOfFaces]; // ie polygons see P3D Lod Faces
ulong nSections;
LODSection LODSections[nSections]; // see P3D Lod Sections
ulong nNamedSelections;
NamedSelection NamedSelections[nNamedSelections]; // see P3D Named Selections
ulong nTokens;
NamedProperty NamedProperties[nTokens];
ulong nFrames;
Frame Frames[nFrames]; // see P3D Lod Frames
ulong IconColor;
ulong SelectedColor;
ulong Unknown;
ulong nProxies;
LodProxy LodProxies[nProxies]; // see [[[P3D Lod Proxies]]
};
VertexTable
struct
{
ulong Count;
ulong PointFlags[Count]; // compressed. see P3D Point 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.
UVPair
struct
{
float U,V;
}
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;
}