FF7/WorldMap Module
Contents
Preamble
The following was originaly described by Tonberry, in qhimm's forum. It was completed by Ficedula sometimes later, who reversed texture data.
Two formats
BOT and MAP files are similar; BOT files are redundant and look like optimized versions of the corresponding MAP files.
Content
- WM0 is the above water map.
- WM2 is the underwater (submarine) map.
- WM3 is the snowstorm map.
MAP Format
File Structure
A worldmap file is divided in sections of 0xB800 bytes, each section representing a square block of the map.
Map Block
Each block consists in 16 meshes, organized in a grid-like fashion:
| 0 | 1 | 2 | 3 |
| 4 | 5 | 6 | 7 |
| 8 | 9 | 10 | 11 |
| 12 | 13 | 14 | 15 |
A block is recorded following the structure (all pointers are expressed in bytes relative to offset 0 of block):
For each m in 16 meshes:
| size | description |
|---|---|
| 4 bytes | Pointer to compressed data for mesh m |
Followed by, for each m in 16 meshes:
| size | description |
|---|---|
| variable | Compressed data for mesh m |
The data for each mesh is independently compressed using LZSS, so the first 4 bytes are the size in bytes of the compressed data and the rest is the compressed data itself.
WM0.MAP
wm0.map contains 68 blocks. The first 63 of them are arranged in a grid-like fashion, made of 7 rows of 9 columns, like this:
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 |
| 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
| 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 |
| 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 |
| 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 |
| 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 |
The last 5 meshes 63, 64, 65, 66, 67 and 68 replaces meshes 50, 41, 42, 60, 47 and 48 (respectively), according to the story of the game.
Mesh Structure
A worldmap mesh is recorded like this:
Header:
| size | description |
|---|---|
| 2 bytes | Number of triangles |
| 2 bytes | Number of vertices |
For each triangle t in number of triangles:
| size | description |
|---|---|
| 1 byte | Index of vertex 0 of triangle t |
| 1 byte | Index of vertex 1 of triangle t |
| 1 byte | Index of vertex 2 of triangle t |
| 1 byte | Walkmap status of triangle t (see below) |
| 1 byte | Coordinate u in texture for vertex 0 |
| 1 byte | Coordinate v in texture for vertex 0 |
| 1 byte | Coordinate u in texture for vertex 1 |
| 1 byte | Coordinate v in texture for vertex 1 |
| 1 byte | Coordinate u in texture for vertex 2 |
| 1 byte | Coordinate v in texture for vertex 2 |
| 2 bytes | Texture (see below) |
For each vertex v in number of vertices:
| size | description |
|---|---|
| 2 bytes | Coordinate x of vertex v (signed) |
| 2 bytes | Coordinate y of vertex v (signed) |
| 2 bytes | Coordinate z of vertex v (signed) |
| 2 bytes | (Unknown: Coordinate w of vertex v?) |
For each vertex v in number of vertices:
| size | description |
|---|---|
| 2 bytes | Coordinate x of normal for vertex v |
| 2 bytes | Coordinate y of normal for vertex v |
| 2 bytes | Coordinate z of normal for vertex v |
| 2 bytes | (Unknown: Coordinate w of normal for vertex v? "Always 0") |
Walkmap
| code | description |
|---|---|
| 0x23 | Deep sea (can't land highwind, water spray when flying low) |
| 0x22 | No sea spray from highwind, can't land |
| 0x21 | No sea spray from highwind, can't land |
| 0x20 | No sea spray, can land and walk |
Observe that 0x21 and 0x22 describe the same status; it is thought that it may differentiate chocobos' behavior.
Texture
The lower 9 bits contain a texture number (0-511, but only 0-281 appear to be used). The text files in the Reeve download show how each number maps to one (or more) .TEX files within WORLD_US.LGP (see [[FF7/LGP format] LGP format]). The upper bits have something to do with texture coordinate mapping.
BOT format
(FIXME)
