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 PackedUnknown[gridZ][gridX] // seems to be related to clutters or sat mask distance as it is responsible for the clutterbug
float PackedElevation[gridZ][gridX]//
/* packed data corresponds to the standard pbo compression format */
structMaterials Materials;
structModels Models;
structClassedModels ClassedModels;
//something grid related[size unknown]
// followed by:
byte[texZ][texX] bytes2 //seems to be connected to roads, runways and special grounds
byte[gridZ][gridX] bytes3 //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];
}
there is always a minimum of one rvmat entry. The first entry is *always* 0x00 0x00 (no file)
the *actual* number of files listed is therefore *always* one less than nRvmatEntries
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?
}
Discussion
- For the TextureIndices block I found out that it is organized in 8x4 blocks. If the block starts with 0x00 you just read in 32 short values describing the block. Otherwise you mostly see 2 identical short values describing one 8x4 block filled just with this value. Sometimes instead of the 0x00 value or the 2 identical short values, other values occur probably describing what sort of data follows and what position the next 8x4 block in the whole texX x texZ block has. But I am still not sure what order these 8x4 blocks follow. The TextureIndices block also seems to start with some "header" data which I couldnt identify so far. --T_D 12:11, 13 October 2008 (CEST)
- The unknown int in the the TextureGridRoads block is the checksum of the packed data before so it does not belong to the TextureGridRoads block --T_D 14:54, 17 October 2008 (CEST)
- Agreed, yeah... saw that, also, maxObjectID isn't part of the TextureGridRoads structure and it will probably end up really being NoOfObjects.
- No it is not NoOfObjects. Already checked that by reading objects from 8WVR and comparing readed objects with this value --T_D 04:33, 18 October 2008 (CEST)
- Experience has taught me that one can never be to certain about these things until one is certain, if you know what I mean... :)
- It maybe MaxObjectId it maybe not... time will tell.
- Building the standard SampleMap.pew into a 8wvr.wrp yeilds 5134 obejcts, then into a oprw18.wrp yeilds 5132 in the MaxOjectId/NoOfObjects field. If you add 1 to this value this is the number of obejcts that happens to be in the array of objects in this particular file.
- However, this senario doesn't hold true for a certain 'ca' mod oprw18.wrp. That value (as I mentioned earlier) is 637,876 and the number of actual objects in the list array is 602,481.
- This may be because there is a prior structure in the file that denotes out of the 637,876 objects ones that are not specified in the Objects array... dunno, well see if that pans out.
- The most logical senario is that this is the NoOfObjects less some other structure count = ObejctList count.
- If this isn't the senario then there maybe another ObjectCount item lying around the file somewhere that does indicate how many objects are in the objects list array.
- this block ushort[gridZ][gridX] unknown //packed seems to consist of random numbers. So my guess is, that these random values are used to calculate the positions of the clutter models, so that the island is always looking the same without saving the pos of every grass model. Could this be the case? --T_D 13:50, 19 October 2008 (CEST)