FF7/P

Feel free to add more information.

"P" Polygon File Format

This is a short diagram of the file structure

.p-File
   |
   +- Header
   |
   +- Vertices[]
   |
   (+- Normals[])
   |
   (+- Texture Coords[])
   |
   +- Vertice Colors[]
   |
   +- Polygon Colors[]
   |
   +- Edges[]
   |
   +- Polygons[]
   |
   +- Hundrets[]
   |
   +- Groups[]
   |
   +- BoundingBox
   |
   +- Normal Index Table[]

[] = a variable-sized array

.P File Header

The .p files have a 128-Byte-long Header. The following is the known structure of the header.

Table 1: P File header

Off	00	01	02	03	04	05	06	07	08	09	0A	0B	0C	0D	0E	0F
00	01	00	00	00	01	00	00	00	VertexColor				A
10	NumNormals				00	00	00	00	NumTexCoords				NumVertices
20	NumEdges				NumPolygons				00	00	00	00	00	00	00	00
30	H				NumGroups				G				01	00	00	00

All Values, that can be read out in this part of the header are 4-Byte-Integers

This 64 bytes long header is followed by 64 bytes of unknown data which are to be skipped. These 64 bytes of data look like offsets of parts of file, but in one large file. One (not allways first) long is smallest, and others are little larger.

typedef struct
{
     long off00;
     long off04;
     long VertexColor;
     long a;
     long NumNormals;
     long off14;
     long NumTexCs;
     long NumVertices;
     long NumEdges;
     long NumPolys;
     long off28;
     long off2c;
     long h;
     long NumGroups;
     long g;
     long off3c;
     long unknown[16];
} 
t_p_header;

Here are the meanings of values from header:

VertexColor	Specifies if Vertex-Colors are used (0=no,1=yes; default: 1)
NumVerts	Count of Vertices
NumNormals	Count of Normals (always 0 in Battle files)
NumTexCs	Count of Texture Coords
NumNormInds	Count of Normal Indices
NumEdges	Count of Lines for WireFrame-Model
NumPolys	Count of Polygons
H	Count of Hundrets Chunk Entries (Textures?)
NumGroups	Count of Groups
G	? (sometimes 0 or 1)(but usually 1), something to do with texturing probably
A	Unknown, usually equal to NumVertices

Vertices

Vertices are stored as array of structure ‘vertex’ below, which is triplet of float numbers. Numbers specify point in 3D space. Size of this array is specified in header. Size of vertex section is ( 12 * NumVertices ). Section is allways present in the file.

struct s_vertex {
    float              x, y, z;
}  vertex;

// structure size = 12 bytes

Vertex normals

Same format as vertices. Though, each of coordinate means vertex normal orientation instead of position. Size of this section is ( 12 * NumNormals ). Section is allways present in the file.

Texture coordinates

Array of vertex texture coordinates. Size of this section is ( 8 * NumTexCoords ). Section is optinally present in the file ( sometimes NumTexCoords is 0 ). Texture coord references are to be read through group information.

Vertex colors

Vertex colors are stored as array of colors, each color is specified by four bytes. Color is in B8G8R8A8 format, that means that first byte specifies Blue, second specifies Green, third specifies Red and fourth specifies Alpha. Alpha byte has usually value ‘255’, so its at full opacity. Size of this section is ( 4 * NumVertices ). Section is allways present in the file.

Polygon colors

Polygon colors are stored in the same manner as vertex colors. Size of this section is ( 4 * NumPolygons ). Section is allways present in the file.

Edges

Dunno. Looks like a array of indexes. Each index has value in range 0 .. NumVertices. Size of this section is ( 4 * NumEdges ). Section is optionally present in the file ( sometimes NumEdges is 0 ).

Polygons

Array of polygon definitions. I know only meaning of values which specify vertex indexes. Vertex indexes can’t be used directly to select vertices, you have first to read group information, there you will find information on which polygons and vertices you should be used to form a model part. Polygons have group-relative indexes to vertices (that means that in each group these indexes start from 0 ). I guess that 'ps' indexes have something to do with normals and 'pu' with edges. In battle models all three 'pu' indexes seem to be unintialized (all have the same values for all polygons). Size of this section is ( 24 * NumPolygons ). Section is allways present in the file.

struct {
    unsigned short     zero, VertexIndex[3], ps[3], pu[3], u[2];
} Ppolygon;

Table 1: P File header

Off	00	01	02	03	04	05	06	07	08	09	0A	0B	0C	0D	0E	0F
00	00 00		VertexIndex1		VertexIndex2		VertexIndex3		ps1		ps2		ps3		pu1
10	pu2		pu3		u1		u2

Hundreds

No idea. Size of this section is ( 100 * H ).

Groups

Table 1: P File header

Off	00	01	02	03	04	05	06	07	08	09	0A	0B	0C	0D	0E	0F
00	PrimitiveType				PolygonStartIndex				NumPolygons				VerticesStartIndex
10	NumVertices				?				?				?
20	?				?				?				TexCoordStartIndex
30	AreTexturesUsed				TextureNumber

struct {
	unsigned long    PrimitiveType;
	unsigned long    PolygonStartIndex;
	unsigned long    NumPolygons;
	unsigned long    VerticesStartIndex;
	unsigned long    NumVertices;
	unsigned long    u1;
	unsigned long    u2;
	unsigned long    u3t;
	unsigned long    u4;
	unsigned long    u5;
	unsigned long    u6;
	unsigned long    TexCoordStartIndex;
	unsigned long    AreTexturesUsed;
	unsigned long    TextureNumber;
} group; 
// also called pool56, size is 56 bytes

Section contains array of group information. Each group specifies group of polygons. To read this group’s geometry you have to read polygons from polygon segment. First polygon is one with index group.PolygonStartIndex, number of polygons is defined by group.NumPolygons. Polygon has indexes of vertices. These indexes are group-relative and that means that you have to add group.VerticesStartIndex to each vertex index. It’s the same with vertex texture coords. Their indexes are group-relative too, to each index you have to add group.TexCoordStartIndex.

If group.textures_used is equal 1 then texture is applied on all polygons of current group. If its 0 there is no texture. If its 1 then group.TextureNumber defines which texture to use on polygons. Though, texture name is not specified inside the P-file, it is specified in HRC or DA file, which loads model as a whole ( it points to texture files, P-files, animation files etc.) Size of this section is ( 56 * NumGroups ).

Bounding box

Six 4-byte floats in order max( x, y, z ), min( x, y, z ). Sometimes just zeroes. Size of this section is 24 bytes.

Normal index table

Not checked yet. Size of this section is ( 4 * NumVertices ).