AVFX files are organized as a nested series of blocks, with each block following the format:

Name: 4 bytes
Size: 4 bytes
Contents: [Size] bytes

The contents of a block can further contain other blocks. It is also worth noting that the name of a block is reversed from its actual meaning. For example, the "top-level" block for an AVFX file is "XFVA"(AVFX reversed). Names which are fewer than 4 character are also padded out to 4 bytes. Blocks are also padded out to be 4-aligned, so even if Sizeis 3, there will be an extra 00 before the next block starts.

Overview

Note: the names of the blocks are reversed for readability. Also, the notation TmLn[], for example, simply means several sequential TmLn blocks, one directly after the other. There is no "list" structure in AVFX files.

The structure is also abridged for brevity, the full list of parameters can be found at the link below.

AVFX:
    Ver: the AVFX version used?
    
    ...parameters....
    
    ScCn: number of schedulers in this file (always 1)
    TlCn: number of timelines
    EmCn: number of emitters
    PrCn: number of particles
    EfCn: number of effectors
    BdCn: number of binders
    TxCn: number of textures
    MdCn: number of models
    
    Schd: a scheduler block
    TmLn[]: a list of timeline blocks
    Emit[]: a list of emitter blocks
    Ptcl[]: a list of particle blocks
    Efct[]: a list of effector blocks
    Bind[]: a list of binder blocks
    Tex[]: a list of texture blocks
    Modl[]: a list of model blocks

(Full structure)

Scheduler (Schd)

Schd:
    ItCn: item count
    TrCn: trigger count, always 12
    Item[]: a list of items
    Trgr[]: a list of triggers, always 12 Trgr blocks

Items and Triggers

The way Item and Trgr blocks are organized is somewhat unintuitive. Both of them have an identical structure:

Item or Trgr:
    bEna: enabled
    StTm: start time
    TlNo: timeline index

However, each subsequent Item/Trgr will have the data of the previous appended to it. For example:

Item:
    bEna
    StTm
    TlNo
    
Item:
    bEna : from item #0
    StTm : from item #0
    TlNo : from item #0
    bEna
    StTm
    TlNo
    
  Item:
    bEna : from item #0
    StTm : from item #0
    TlNo : from item #0
    bEna : from item #1
    StTm : from item #1
    TlNo : from item #1
    bEna
    StTm
    TlNo  

For this reason, the easiest way to read a list of Item is to take the last one, and split it into 3-block chunks.

Timeline (TmLn)

TmLn:
    ...parameters...
    
    TICn: number of items
    CpCn: number of clips
    
    Item[]: list of item blocks
    Clip[]: list of clip blocks

(Full structure)

Timeline Items

Timeline items have this structure, and are similar to scheduler items in that each item contains the data of the previous ones as well.

Timeline clips

Timeline clips are different in that the data they contain is not organized into blocks, but is rather one continuous 164-byte:

4-byte string, reversed
4 4-byte ints
4 4-byte floats
4 32-byte strings

Emitter (Emit)

Emit:
    SdNm: the path to a sound file (.sdm)
    
    ...parameters....
    
    PrCn: number of particles
    EmCn: number of emitters
​
    ...animation curves...
    
    ItEm[]: list of emitter items
    ItPr[]: list of particles items
    
    Data: depends on the emitter type

(Full structure)

The Data block contains information relevant to the emitter's type (specified in the EVT parameter). Depending on the type, the Data block may not exist at all (structures).

Emitter/Particle Items

ItEm and ItPr blocks share the same basic structure, but follow the same pattern as items and triggers within schedulers, where previous items' data is appended to each subsequent one. However, in an emitter, all of the ItEm data is included in the ItPr data. As an example:

ItEm:
    [ItEm data #0]
    
ItEm:
    [ItEm data #0]
    [ItEm data #1]
    
ItEm:
    [ItEm data #0]
    [ItEm data #1]
    [ItEm data #2]
    
ItPr:
    [ItEm data #0]
    [ItEm data #1]
    [ItEm data #2]
    [ItPr data #0]
    
ItPr:
    [ItEm data #0]
    [ItEm data #1]
    [ItEm data #2]
    [ItPr data #0]
    [ItPr data #1]

Particle (Ptcl)

Ptcl:
​
    ...parameters...
    
    UvSN: number of UV Sets
    
    ...more parameters...
    
    ...animation curves...
    
    Smpl: Simple animations (optional)
    
    UVSet[]: a list of UVSet blocks
    
    Data: depends on particle type
    
    TC1: texture color 1
    TC2: texture color 2 (optional)
    TC3: (optional)
    TC4: (optional)
    TN: texture normal
    TR: texture reflection
    TD: texture distortion
    TP: texture palette

(Full structure)

Like with emitters, the contents of the Data block depends on the particle type (parameter PrVT ). Some particle types do not contain a Data block (structures).

• ​Simple animation structure​

• ​UV Set structure​

• ​Texture color 1 structure​

• ​Texture color 2, 3, and 4​

• ​Texture normal​

• ​Texture reflection​

• ​Texture distortion​

• ​Texture palette​

Particle Simple Animations

The Smpl block contains 2 unique parameters: Cols and Frms. Cols is 16 bytes, where each 4 bytes represent an rgba color (each byte is one channel). Frms is 8 bytes, where each 2 bytes is an integer.

Effector (Efct)

Efct:
    ...parameters...
    
    Data

(Full structure)

As with emitters and particles, the Data block (structures) depends on the type of effector, and may not exist.

Binder (Bind)

Bind:
    ...parameters...
    
    PrpS: Start binder properties
    Prp1: binder properties 1
    Prp2: binder properties 2
    PrpG: Goal binder properties
    
    Data

(Full structure)

Data is, once again, dependent on the type of binder, and may not exist (structures). Each of the binder properties have this structure.

Texture (Tex)

Texture blocks are simply paths to atex files within the game's internal file structure.

Model (Modl)

The embedded models have 4 possible blocks within them: VNum , VDrw , VEmt, and VIdx . All 4 of the blocks can be in the same model, however VNum and VEmt are always paired, as are VIdx and VDrw .

VIdx

This is a list of 2-byte integers, where each 3 integers represents a triangle in the model. The integers themselves are the indexes of vertices within VDrw .

VDrw

VDrw is a list of vertices, where each vertex is 36 bytes long with the following format:

4 2-byte floats: position
4 1-byte ints: normal
4 1-byte ints: tangent
4 1-byte ints: color
4 2-byte floats: uv1
4 2-byte floats: uv2

VEmt

This is a list of 28-byte vertices, with the following format:

3 4-byte floats: position
3 4-byte floats: normal
4 1-byte ints: color

VNum

This is a list of 2-byte integers, where each integer corresponds to a vertex in VEmt (so the length of elements in VNum always equals the number in VEmt).

Curves

Curves have the following structure:

[Curve Name]:
    ....parameters...
    
    Keys

(Full structure)

The name of a curve varies, but some examples are X ,RGB , SclA , etc. They are used to animate motion over time. Keys is a single block which contains the information on the shape of the curve. Every 16 bytes in Keys corresponds to a single keyframe, with the following format:

2-byte integer: time
2-byte integer: type
4-byte float: X
4-byte float: Y
4-byte float: Z