Alan Wake 2

[Scobalula]

On 9/1/2025 at 4:05 PM, bladers said:

I hope you are successful but i tried for a month even using AI for help. There are just several different types of models, up to 6 or more. Lod offset and Vertex Offset are just not reliable as the data are stacked in different order depending on the type of model.

So I'm interested to know how you are doing it, i tried to unpack the .exe and really didn't see anything in there that was helpful

There is only 1 model format to my knowledge that is used in the game, there is another present in the game files but it seems to just be left over data from older versions of Northlight (Control, Quantum, etc.) used in the game.

The format is variable length and there are tons of checks based off data presence it does (for example a particular block of data isn't present if a count in the header is not present, and then other data will not be present if another check doesn't pass based off previous data) which probably adds to the complexity of parsing it.

Each individual mesh also has variable arrays within it (for example vertex attribute tables).

I'm still working on this but last few weeks we've had a few big projects at work and I've taken some OOH work for OT so time is a little scarce atm.

Edited 22 hours ago by Scobalula

[bladers]

9 hours ago, Scobalula said:

There is only 1 model format to my knowledge that is used in the game, there is another present in the game files but it seems to just be left over data from older versions of Northlight (Control, Quantum, etc.) used in the game.

The format is variable length and there are tons of checks based off data presence it does (for example a particular block of data isn't present if a count in the header is not present, and then other data will not be present if another check doesn't pass based off previous data) which probably adds to the complexity of parsing it.

Each individual mesh also has variable arrays within it (for example vertex attribute tables).

I'm still working on this but last few weeks we've had a few big projects at work and I've taken some OOH work for OT so time is a little scarce atm.

I guess thats one way to look at it, one model format with different types. But yeah all of what you described is what i see in the model data files. That's what makes it so hard to build a script for.

You end up with a model definition from the files like :

mesh index

lodId

vertCount

 faceCount

 bytes to skip to vertex offset - distance into the UV and Vertex sections, respectively, measured within the current LOD’s section (i.e., NOT absolute file positions). These are cumulative within an LOD group except for the first mesh in that LOD.

bytes to skip to vertex offset 2 - distance into Vertex sections

byteForFace

face_offset - count of indices to skip after the vertex data within the LOD section (in INDICES, not bytes). To convert to bytes, multiply by byteForFace.

bonesPerVertex

Vertex Size

UV Size

LOD offset (start of the mesh’s LOD block)

 

You can even compute and  Validate all “bytes to skip” and “face_offset” fields against vert/face count.

Mesh Example: 

Mesh 1:

offset: 0x353 → mesh index = 4
offset: 0x357 → lodId = 3
offset: 0x35b → vertCount = 324
offset: 0x35f → faceCount = 232
offset: 0x363 → bytes to skip to vertex offset = 0
offset: 0x367 → bytes to skip to vertex offset 2 = 0
offset: 0x36b → byteForFace = 2
offset: 0x36f → face_offset = 0
offset: 0x373 → bonesPerVertex = 1
Vertex Size = 12
UV Size = 8

Mesh 2:
offset: 0x3ca → mesh index = 0
offset: 0x3ce → lodId = 2
offset: 0x3d2 → vertCount = 542
offset: 0x3d6 → faceCount = 465
offset: 0x3da → bytes to skip to vertex offset = 2592
offset: 0x3de → bytes to skip to vertex offset  2 = 3888
offset: 0x3e2 → byteForFace = 2
offset: 0x3e6 → face_offset = 696
offset: 0x3ea → bonesPerVertex = 1
Vertex Size = 12
UV Size = 8

Mesh 3:
offset: 0x441 → mesh index = 0
offset: 0x445 → lodId = 1
offset: 0x449 → vertCount = 974
offset: 0x44d → faceCount = 932
offset: 0x451 → bytes to skip to vertex offset = 6928
offset: 0x455 → bytes to skip to vertex offset 2 = 10392
offset: 0x459 → byteForFace = 2
offset: 0x45d → face_offset = 2091
offset: 0x461 → bonesPerVertex = 1
Vertex Size = 12
UV Size = 8
 

And here for validation:

## PRE-COMPUTED MESH SIZES
Mesh 1:
- UV data: 324 vertices × 8 bytes = 2,592 bytes 
- Vertex data: 324 vertices × 12 bytes = 3,888 bytes 
- Face data: 232 faces × 3 indices × 2 bytes = 1,392 bytes 
- Total Mesh 1 size = 7,872 bytes 

Notice the 2,592, and 3,888 matches the skip bytes #1 and #2 for mesh 2.

Mesh 2:
- UV data: 542 vertices × 8 bytes = 4,336 bytes 
- Vertex data: 542 vertices × 12 bytes = 6,504 bytes 
- Face data: 465 faces × 3 indices × 2 bytes = 2,790 bytes 
- Total Mesh 2 size = 13,630 bytes 

Notice adding the UV size of both mesh 1 & mesh you (2,592 + 4,336), and vertex size of both mesh 1 & mesh 2 (3,888 + 6,504) you end up matching the skip bytes #1 and #2 for mesh 3.

Mesh 3:
- UV data: 974 vertices × 8 bytes = 7,792 bytes 
- Vertex data: 974 vertices × 12 bytes = 11,688 bytes 
- Face data: 932 faces × 3 indices × 2 bytes = 5,592 bytes 
- Total Mesh 3 size = 25,072 bytes 

..similar thing to validate faceoffset.

But even with all of this info and then some, because of how the data is layers, its impossible to figure out the entire thing looking at the data files itself. So how are you discovering the model format by looking at the executable, are you running a disassembler or decompiler or something? How are you doing it.