FF7/Battle model format (PSX)

Playstation battle model format

The entire file is compressed using LZS format and is decompressed into the playstation user memory for a battle. The file consists of several section blocks, a header, compiled HRC and model information, battle animations, a texture image in TIM format, and optional weapon models. All integers short or long are little endian based. This includes some of the animation data as well.

Battle model header

The header section is a sequence of little endian 32 bit unsigned integers. The first integer (entitled SectionCount) contains the number of pointers offset from the begining of the file. The remaining integers are SectionCount number of pointers.

Battle model HRC/model information

This is the first section and consists of real model data and bone structure. Without the animation information the model CANNOT be displayed properly.

HRC data

This data resembles Hierarchy files (.HRC), from the PsyQ library. To be correct the HRC files were used to generate this information hence it's called HRC data. The HRC data begins with an unsigned 32 bit integer (BoneCount) indicating the number of bones. Following this is the root bone, which is allays zero'd. After the root bone is BoneCount number of bones. The bone information is stored in a structure like the thus (using C conventions):

typedef struct
{
   uint16 Parent;
   int16  Length;
   uint32 Offset;
} FF7_bone;

Where offset is relative to the begining of the section. If Offset is 0 then the object is a Joint otherwise it's a bone. All FF7 bone lengths are negative.

Model information

Following the HRC Data is the model information, these are referenced by offsets in the Bone structure. Each bone has it's own model section specific too it. Each bone section has the following information uint32 VertexCount (int bytes), Vertices, Textured Triangle Count (Poly Count Structure), Textured Triangles, Textured Quadric Count (PCS), Textured Quadrics, Triangle Count (PCS), Triangles, Quadric Count (PCS), Quadrics. If the count of any of these is zero then the follow data is a Poly Count Structure.

All structure information is 32 bit aligned for the PSX GPU.

typedef struct
{
   uint16  Count;
   uint16  TexPage;
} PolyCount;

typedef struct
{
   int16  X;
   int16  Y;
   int16  Z;
   int16  Unused;
} Vertex;

typedef struct
{
   uint8  Red;
   uint8  Green;
   uint8  Blue;
   uint8  Unused;
} Color;

typedef struct
{
   uint16  A;
   uint16  B;
   uint16  C;
   uint16  D;
} PolyIndices;

typedef struct
{
   PolyIndices  Vertexs;
   Color        Colors[3];
} ColorTriangle;

typedef struct
{
   PolyIndices  Vertexs;
   Color        Colors[4];
} ColorQuadric;

typedef struct
{
   PolyIndices  Vertex;
   uint8        U0, V0;
   unint16      Flags;
   uint8        U1, V1;
   uint8        U2, V2;
} TexTriangle;

typedef struct
{
   PolyIndices  Vertex;
   uint8        U0, V0;
   unint16      Flags;
   uint8        U1, V1;
   uint8        U2, V2;
   uint8        U3, V3;
   uint16       Unused;
} TexQuadric;

The Flags field on the Textured polygons contains the texture palette offset for the TIM texture file associated with the model. The TexPage is not used in any of the battle models however battle scenes do use this to refer another page of texture data (for 8bpp TIM's used in them).

Battle animations

This is identical to the PC version of FF7.

Texture information

see TIM format

Weapon models

These are identical to the bone model structures, as the weapon models are treated as bones in character animation. They have NO texture data period.