Ultima VIII Map Format Information by Mad Hatter
Ultima 8 map format
===================
v1.04 - 3rd of May, 1997
By Michael De Piazzi (aka Mad Hatter)
If you know anything else about the Ultima 8 map format, please send email to
me at garydep@iinet.net.au
You should be able to find the latest version of this file -somewhere- on my
homepage at:
http://www.iinet.net.au/~garydep/michael.html
Contents
========
- Introduction & notes
- FIXED.DAT and NONFIXED.DAT format
- GLOB.FLX format
- ITEMCACH.DAT format
- Getting data from save games
Introduction & notes
====================
Data for the Ultima 8 maps are stored in multiple files. Each files purpose
and format can be found in the appropriate section of this document. There
are probably more files relating to the maps, but I haven't worked out which
ones yet.
All numbers are in decimal. Offsets are 1 indexed (The first byte is 1)
FIXED.DAT and NONFIXED.DAT format
=================================
FIXED.DAT can be found in the static directory and NONFIXED.DAT can be found
in the GAMEDAT directory or inside U8SAVE.000 in the SAVEGAME directory (See:
Getting data from save games). FIXED.DAT contains all the objects that are in
a fixed position (Floor, walls, trees) and NONFIXED.DAT contains all the
objects that can be moved around and will stay where you put them (Swords,
keys, etc)
--- Header chunk ---
This tells you how many maps there are, the file positon of the maps and the
size of each map
Offset Size Description
85 2 Number of maps in file (m) (Should be 256)
129 m*8 Map information chunks
--- Map information chunk ---
There should be 256 maps in the file. The first map is Map 0 in the game and
the 256th map is Map 255 in the game.
Offset Size Description
1 4 Position in file of beginning of map
(Add 1 to this number for actual file position)
5 4 Size in bytes of map
--- Map format ---
To work out how many objects in the map there are, divide the size of the map
by 16
Each object in the map is defined by:
Offset Size Description
1 2 Map X position
3 2 Map Y position
5 1 Map Z position
6 2 Type number
8 1 Frame number
9 2 ??? Unknown ???
11 2 * Glob number
13 1 ** NPC number
14 1 ** Map number
15 2 ??? Unknown ???
* Only applies if object is a glob. I think the object is a glob (See:
GLOB.FLX format) if the type number is 2, but there's still parts missing when
you try draw the map
** Only applies if object is a NPC. All of the NPC information is stored in
map 0 of NONFIXED.DAT
To convert the map XYZ coordinates to screen XY coordinates, use these
formulas:
ScreenX = (MapX - MapY) / 4
ScreenY = (MapX + MapY) / 8 - MapZ
GLOB.FLX format
===============
This file contains predefined map sections (Such as floors and walls) and can
be found in the STATIC directory.
--- Header chunk ---
Offset Size Description
85 2 Number of globs in file (g)
129 g*8 Glob information chunks
--- Glob information chunk ---
Offset Size Description
1 4 Position in file of beginning of glob
(Add 1 to this number for actual file position)
5 4 Size in bytes of glob
--- Glob format ---
Offset Size Description
1 2 Number of objects in GLOB.FLX (n)
3 n*6 Object information chunks
--- Object information chunks ---
Offset Size Description
1 1 Map X position
1 1 Map Y position
1 1 Map Z position
1 2 Type number
1 1 Frame number
To convert the map XYZ coordinates to screen XY coordinates, use these
formulas:
ScreenX = (MapX - MapY) / 2
ScreenY = (MapX + MapY) / 4 - MapZ
If you're adding it into the map, use the following formulas:
MapX = MapX * 2 + OriginalMapX
MapY = MapY * 2 + OriginalMapY - 576
MapZ = MapZ + OriginalMapZ
ScreenX = (MapX - MapY) / 4
ScreenY = (MapX + MapY) / 8 - MapZ
OriginalMapX, OriginalMapY and OriginalMapZ are the coordinates given when
the object in FIXED.DAT or NONFIXED.DAT is a glob. Also these formulas only
draw the map and it sort of looks right from memory of what the map looked
like, so don't take it as a precise formula.
ITEMCACH.DAT format
===================
This file seems to be a temporary item cache for the current map you are on.
I'm guessing that once you go to another map its data is dumped into the
NONFIXED.DAT file. It's found in the GAMEDAT directory or inside U8SAVE.000
in the SAVEGAME directory (See: Getting data from save games).
--- Header chunk ---
Offset Size Description
85 2 Number of files inside ITEMCACH.DAT (Should be 2)
129 n*8 Information chunks
--- Information chunk ---
Offset Size Description
1 4 Position in ITEMCACH.DAT of beginning of file
(Add 1 to this number for actual file position)
5 4 Size in bytes of file
I'm not sure what the data in the second file is yet, but I know a bit about
the format of the first file. It has information on 9216 objects stored in it
in the following format:
If the object is not an NPC:
Offset Size Description
1 18432 X positions of objects (9216 2 byte numbers)
18433 18432 Y positions of objects (9216 2 byte numbers)
36865 9216 Z positions of objects (9216 1 byte numbers)
46081 18432 Type numbers of objects (9216 2 byte numbers)
64513 9216 Frame numbers of objects (9216 1 byte numbers)
73729 36864 ??? Unknown ???
110593 9216 * NPC number (9216 1 byte numbers)
119809 9216 * Map number (9216 1 byte numbers)
129025 18432 ??? Unknown ???
* Only applies if object is a NPC. It seems the first 256 objects are reserved
for the NPCs
Getting data from save games
============================
The format of a savegame is as follows
Offset Size Description
1 23 Id = `Ultima 8 SaveGame File.'
24 1 Null byte (0)
25 1 Number of files inside savegame file
Offset Size Description
1 4 Length of file name (f)
5 f File name (Null terminated string)
5+f 4 Length of data (d)
9+f d Data for file
The original files are stored in U8SAVE.000 in the SAVEGAME directory
