Ashen reverse engineering

Reverse engineering of an N-Gage game Ashen

• Can extract game resources

Usage

Setup

1. Place the ROM

   mkdir rom/
   cp /path/to/packfile.dat rom/packfile.dat

Extracting files

File parsing is in test suite only, for now.

• Unpack game resources
  1. Run deflate test

     cargo test --release -- --ignored parse_rom_packfile

  • This will split and deflate game files into output/deflated/ directory.
  • Files are named with the address as they appear in the asset table.
  • Files that begin with decompression signature are automatically decompressed and named with -deflated suffix. This automatic decompression doesn't work well for collection assets such as textures.
• Parse resources (make sure to unpack first)
  1. Run parsing tests

     cargo test --release -- --ignored parse_rom_asset

  • This will parse select few game files into output/parsed/ directory
  • Directions on how to opened parsed files are available here

Roadmap

File formats and extraction

• Gamma table
  • Purpose
    • Look up table for brightness when changing gamma in settings
  • Output format
    • PNG image
• Color map
  • Purpose
    • Look up table for 12-bit RGB colors, because textures are stored in 256 indexed color format
    • There is also ghost version for when you use Ghost Vision Goggles in game
    • There are unique color maps for monsters, pick-ups (and some other models), UI sprites, and levels
  • Output format
    • PNG image
• Model
  • Purpose
    • Texture, geometry, and model data
  • TO DO
    • Figure out what to do with pre-calculated face and vertex normals
  • Output format
    • Blender Python script that can be executed with

      blender -P /path/to/script.py

    • Automatically sets up Cycles material and animations as shape keys in dope sheet's shape key editor
• Sky
  • Purpose
    • Color map and skybox texture
  • Output format
    • PNG image
• Skins
• Level geometry
• Level collision
• Level waypoints
• Sprite
• Texture
  • Purpose
    • Texture info - offsets, texture dimensions
    • Texture data - color indeces
  • Output format
    • PNG image
    • GIF image for animated textures
• Music and sound effects
  • Purpose
    • Sound effects
    • Music
  • TO DO
    • Improve mixer with pitch, pan, and other sound effects
    • Support sustained instruments
    • Set correct tempo
  • Output format
    • WAV audio file
• String table
  • Purpose
    • Printable strings in UI
  • TO DO
    • Figure out weird non-text characters (probably for controlling in-game events)
  • Output format
    • Plain text

File structure

Important

I use the packfile that comes with Ashen 1.06. Your packfile may have different order, I didn't test with different versions.

Address (HEX)	Asset
00	gamma table
01	creature colormap
02	creature colormap (ghost)
03	ghost creature colormap (ghost)
04	pickup colormap
05	pickup colormap (ghost)
06	jacob colormap
07	level colormap (ghost)
08	player hands colormap
09	player hands colormap (ghost)
0A	aquagore
0B	broodmaw
0C	cryptcrawler
0D	firedeacon
0E	hunter
0F	psistalker
10	stormfluke
11	tentacle
12	wraith
13	primeentity
14	playermodel
15	vanessa
16	rocket
17	grenade
18	fxblast
19	aquagore shot
1A	broodmaw shot
1B	cryptcrawler shot
1C	firedeacon shot
1D	gib generic 1
1E	gib generic 2
1F	gib generic 3
20	blood generic 1
21	charles
22	human gib generic 1
23	human gib generic 2
24	human gib generic 3
25	pickup ammo pistol
26	pickup ammo double pistol
27	pickup ammo shotgun
28	pickup ammo machinegun
29	pickup ammo sniper
2A	pickup ammo grenade
2B	pickup ammo rocket
2C	pickup ammo gatlinggun
2D	pickup weapon pistol
2E	pickup weapon double pistol
2F	pickup weapon shotgun
30	pickup weapon machinegun
31	pickup weapon sniper
32	pickup weapon grenade
33	pickup weapon gatlinggun
34	pickup weapon shockwave
35	pickup ghostvision
36	pickup focitalisman
37	pickup letter
38	pickup key1
39	pickup flakjacket 25
3A	pickup flakjacket 50
3B	pickup flakjacket 100
3C	level1 sky
3D	level2 sky
3E	level3 sky
3F	level4 sky
40	level5 sky
41	level6 sky
42	level1 sky palette (ghost)
43	level2 sky palette (ghost)
44	level3 sky palette (ghost)
45	level4 sky palette (ghost)
46	level5 sky palette (ghost)
47	level6 sky palette (ghost)
48	jacob skin red
49	jacob skin green
4A	jacob skin blue
4B	jacob skin yellow
4C	level1a
4D	level1a collision
4E	level1a waypointnav
4F	level1a colormap
50	level1b
51	level1b collision
52	level1b waypointnav
53	level1b colormap
54	level2a
55	level2a collision
56	level2a waypointnav
57	level2a colormap
58	level2b
59	level2b collision
5A	level2b waypointnav
5B	level2b colormap
5C	level3a
5D	level3a collision
5E	level3a waypointnav
5F	level3a colormap
60	level3b
61	level3b collision
62	level3b waypointnav
63	level3b colormap
64	level4a
65	level4a collision
66	level4a waypointnav
67	level4a colormap
68	level4b
69	level4b collision
6A	level4b waypointnav
6B	level4b colormap
6C	level5a
6D	level5a collision
6E	level5a waypointnav
6F	level5a colormap
70	level5b
71	level5b collision
72	level5b waypointnav
73	level5b colormap
74	level6
75	level6 collision
76	level6 waypointnav
77	level6 colormap
78	level7
79	level7 collision
7A	level7 waypointnav
7B	level7 colormap
7C	level8
7D	level8 collision
7E	level8 waypointnav
7F	level8 colormap
80	leveldm1
81	leveldm1 collision
82	leveldm1 colormap
83	leveldm2
84	leveldm2 collision
85	leveldm2 colormap
86	leveldm3
87	leveldm3 collision
88	leveldm3 colormap
89	leveldm4
8A	leveldm4 collision
8B	leveldm4 colormap
8C	levelmonsters
8D	levelmonsters collision
8E	levelmonsters waypointnav
8F	leveldoors
90	leveldoors collision
91	leveldoors waypointnav
92	sprites
93	texture info
94	sprite texture info
95	textures
96	sprite textures
97	sound data
98	stringtable english uk
99	stringtable english us
9A	stringtable french
9B	stringtable italian
9C	stringtable german
9D	stringtable spanish

Discoveries

• Test level for enemies
  • There is a pool with fish enemies, which I don't remember seeing in the game
• Test level for doors
  • Collision by itself works with other level geometry, geometry by itself also works, but not together

Resources

• Post by HoRRoR
• Debug Windows build with symbols
• Manual