Wrp File Format - OPRWv17 to 24
Introduction
Legend
- byte 8 bits, unsigned.
- ushort 2 bytes, unsigned.
- ulong 4 bytes, unsigned.
- float 4 bytes, signed.
File Format
structHeader Header;
//still unknown stuff here
//followed by
structPeaks Peaks;
structTextureGridMaterials MaterialIndices; //see discussion below. Not fully defined (yet)
ushort PackedRandom[texZ][texX]; //probably random values needed for calculating clutter models position
byte PackedBytes1[gridZ][gridX]; // seems to be related to clutters or sat mask distance as it is responsible for the clutterbug
float PackedElevation[gridZ][gridX];
structMaterials Materials;
structModels Models;
structClassedModels ClassedModels;
//something grid related[size unknown]
// followed by:
byte PackedBytes2[texZ][texX]; //seems to be connected to roads, runways and special grounds
byte PackedBytes3[gridZ][gridX]; //unknown but 0x00 for forests and roads and sea, mostly 0x03 and rarely 0x02
ulong maxObjectID; //not number of objects
ulong ObjectBlockOffset; //amount of bytes used for RoadNets
structRoadNet RoadNets[texZ,texX]; //probably organized in texture grid cells to realize terrain streaming
structObject Objects[unknown];
structMapInfo MapInfos[]; //have to be iterated until EndOfFile
Structures
structHeader
structHeader
{
char signature[4]; //"OPWR"
ulong version; //0x12 = 18
ulong texX,texZ; //textures cell dimensions. 256x256 eg
ulong gridX,gridZ; //elevations cell dimensions. 256x256 eg
float gridSize; //in meters (normally 50.0)
}
structPeaks
structPeaks
{
ulong nPeaks;
float XZY[nPeaks][3]; //Position of the Peak (Z is height)
}
structTextureGridMaterials
structTextureGridMaterials
{
//still need to be worked out
}
structMaterials
structMaterials
{
ulong nMaterials; //Number of Rvmat entries (at least one)
structMaterial Materials[nMaterials];
}
At least one material is always present at the first position of Materials with an empty path, so nMaterials appears to be one more than the real count of materials.
structMaterial
structMaterial
{
asciiz rvmat_path;
byte 0x00;
}
structModels
structModels
{
ulong nModels; //number of models
asciiz model_path[nModels]; //e.g. ca\buildings\kostelik.p3d
}
The ModelIndex in the ObjectsBlock below is a direct reference to one of the above p3d files for that object entry. If there are 99 nModels then the Object entries will contain ModelIndexes between 0 and 98
structClassedModels
structClassedModels
{
ulong nClassedModels; //number of classed models
structClassedModel Models[nClassedModels];
}
structClassedModel
structClassedModel
{
asciiz class_name; //e.g. Land_Hangar
asciiz model_path; //e.g. ca\buildings\kostelik.p3d
float pos[3]; //XZY
ulong unknown;
}
structRoadNet
structRoadNet
{
ulong nRoadParts; // Zero or More...
structRoadPart RoadParts[nRoadParts];
}
Because of the variable length asciiz strings, the actual position of the following Objects block cannot be pre-calculated. Therefore,
the ObjectBlockOffset is also the size (in bytes) of the Roads Block
On a 256 x 256 cell island: Each cell *unconditionally* contains a roadnet entry. If there are no road(s) in that cell, there are no roadparts. There could, alternatively be multiple roads in that cell, and, multiple parts to each road.
For a 256 x 256 cell island with NO roads, the size of this block, the ObjectBlockOffset , would be 256 x 256 x 4 bytes.
structRoadPart
structRoadPart
{
ushort nRoadPositions;
float RoadPositions[nRoadPositions][3]; //XYZ
byte Flags[4];
asciiz Model;
float matrix[12];
}
structObject
structObject
{
ulong ObjectID;
ulong modelIndex;
float matrix[12];
ulong 0x02;
}
modelIndex is a direct reference to the Nth model entry in the Model Block above. If there are 99 p3d files listed in the Model Block, then any given Object entry will contain a modelIndex between 0 and 98. For any island, there are more than 100,000 (p3d) objects on the terrain. The ObjectID uniquely identifies *that* tree, at *that* position. The *same* tree, house, bush, will be used many times on the island at different locations. Thus many object entries contain the same modelIndex. Eg, the same, p3d tree.
structMapInfo
structMapInfo
{
ulong infoType;
if(infoType in [0,1,2,10,11,13,14,15,16,17,22,23,26,27,30]) structType1 type1;
if(infoType in [24,31,32]) structType2 type2;
if(infoType in [25,33]) structType3 type3;
if(infoType in [3,4,8,9,18,19,20,28,29]) structType4 type4;
if(infoType in [34]) structType5 type5;
}
structType1
structType1
{
ulong ObjectId
float x, z
}
structType2
structType2
{
ulong ObjectId
float[4][2] Bounds
}
structType3
structType3
{
long[2] unknown
float[2][2] line?
}
structType4
structType4
{
ulong ObjectId
float[4][2] Bounds
byte[4] Color //rgba
}
structType5
structType5
{
ulong ObjectId
float[2][2] line?
}
Packed Data
All variables starting with "Packed" are compressed with the common BIS algorithm that is also used in paa and OFP pbo files.