RpGeometry

RpGeometry is a RenderWare structure that stores geometric data.

Stream structure

{{{NAME}}}
RenderWare Stream Section
Vendor	{{{VENDORNAME}}}
Module	{{{MODULENAME}}}
Module ID	0x{{{MODULEID}}}
Identifier	0x{{{IDENTIFIER}}}
Chunk ID	0x{{{MODULEID}}}{{{IDENTIFIER}}}
Versions	All
Hierarchy
Parents: None
Children: None
Extensions: None
File Format

When streamed in/out it is usually the child of a Geometry List chunk and the parent of a Struct, Material List and Extension chunk.

The format of the Geometry's Struct chunk is as follows:

int16        format (see below)
int8         number of texture coordinate sets (numTexSets)
int8         native geometry flags (see below)
int32        number of triangles (numTriangles)
int32        number of vertices (numVertices)
int32        number of morph targets (numMorphTargets) (morphing is not used in GTA series, so this is always 1)
#if version < 0x34000
  surface properties:
    float32  ambient
    float32  specular
    float32  diffuse
#endif

#if nativeGeometry == 0
    #if (format & rpGEOMETRYPRELIT)
        RwRGBA   prelitcolor[numVertices] (RwRGBA: uint8 r, g, b, a)
    #endif

    #if format & (rpGEOMETRYTEXTURED | rpGEOMETRYTEXTURED2)
        #repeat numTexSets (see below)
            RwTexCoords    texCoords[numVertices]  (RwTexCoords: float32 u, v)
        #endrepeat
    #endif
   
    RpTriangle   triangles[numTriangles]  (RpTriangle: uint16 vertex2, vertex1, materialId, vertex3)
#endif

#repeat numMorphTargets
    RwSphere    boundingSphere    (RwSphere: float32 x, y, z, radius)
    bool32      has vertices
    bool32      has normals
    #if has vertices
        RwV3d   vertices[numVertices] (RwV3d: float32 x, y, z)
    #endif
    #if has normals
        RwV3d   normals[numVertices]
    #endif
#endrepeat

Format

The following flags describe the behaviour of the mesh during the rendering progress. Some of the flags indicate the existence of data inside the following file format.

Flag	Name	Description
0x0001	rpGEOMETRYTRISTRIP	Is triangle strip (if disabled it will be an triangle list)
0x0002	rpGEOMETRYPOSITIONS	Vertex translation
0x0004	rpGEOMETRYTEXTURED	Texture coordinates
0x0008	rpGEOMETRYPRELIT	Vertex colors
0x0010	rpGEOMETRYNORMALS	Store normals
0x0020	rpGEOMETRYLIGHT	Geometry is lit (dynamic and static)
0x0040	rpGEOMETRYMODULATEMATERIALCOLOR	Modulate material color
0x0080	rpGEOMETRYTEXTURED2	Texture coordinates 2

The 8 bits after the format description give the number of texture coordinate sets (numTexSets). If the value in the file is zero, rpGEOMETRYTEXTURED means there is one set of texture coordinates, rpGEOMETRYTEXTURED2 means there are two.

Native Geometry

Native geometry flags can be rpGEOMETRYNATIVE (0x1) or rpGEOMETRYNATIVEINSTANCE (0x2). If rpGEOMETRYNATIVE is set, the platform dependent geometry data is to be found in the Native Data chunk.

Extension

The extension of an geometry can hold the following chunks in GTA:

• Bin Mesh PLG
• Native Data PLG – (Only for consoles)
• Skin PLG
• Breakable
• Extra Vert Colour
• Morph PLG
• 2d Effect