MOD file

MOD Format

The MOD format is a proprietary binary data structure used to represent and serialize 3D model data, including geometry, textures, materials, and metadata. It employs a chunk-based architecture where each chunk represents a specific data category or type, enabling modular and efficient parsing and serialization.

Alignment

Chunks are written at addresses that are a multiple of `0x20` (32), using `00` bytes to pad as necessary. This is done for efficiency during reading and writing operations.

Chunk Structure

Although every individual chunk is unique, they all follow a similar structure:

Header

Each chunk begins with a header consisting of:

• Opcode (4 bytes): Identifies the chunk type.
• Length (4 bytes): Specifies the size of the chunk payload, excluding the header.

Chunk Types

Below is a list of chunk types with links to detailed descriptions:

• Header (0x00)
• Vertex (0x10)
• VertexNormal (0x11)
• VertexNBT (0x12)
• VertexColour (0x13)
• TexCoord0 to TexCoord7 (0x18 to 0x1F)
• Texture (0x20)
• TextureAttribute (0x22)
• Material (0x30)
• VertexMatrix (0x40)
• MatrixEnvelope (0x41)
• Mesh (0x50)
• Joint (0x60)
• JointName (0x61)
• CollisionPrism (0x100)
• CollisionGrid (0x110)
• EndOfFile (0xFFFF)

Chunk Details

Header (0x00)

• Description: Contains minimal metadata about the MOD file, including creation date and flags.
• Contents: (To be filled)

Vertex (0x10)

• Description: Contains vertex position data for the 3D model.
• Contents: (To be filled)

VertexNormal (0x11)

• Description: Contains normal vector data for vertices, used for lighting calculations.
• Contents: (To be filled)

VertexNBT (0x12)

• Description: Stores additional data such as binormal and tangent vectors for vertices.
• Contents: (To be filled)

VertexColour (0x13)

• Description: Contains color information for vertices, often used for vertex shading.
• Contents: (To be filled)

TexCoord0-7 (0x18 to 0x1F)

• Description: Stores texture coordinate set 0 to 7 for mapping textures onto geometry.
• Contents: (To be filled)

Texture (0x20)

• Description: Contains texture data used for rendering the model.
• Contents: (To be filled)

TextureAttribute (0x22)

• Description: Stores attributes and metadata related to textures.
• Contents: (To be filled)

Material (0x30)

• Description: Defines materials, including shaders and associated textures.
• Contents: (To be filled)

VertexMatrix (0x40)

• Description: Stores transformation matrices for vertices.
• Contents: (To be filled)

MatrixEnvelope (0x41)

• Description: Defines envelopes for vertex weighting and deformation.
• Contents: (To be filled)

Mesh (0x50)

• Description: Contains data for geometric objects, including faces and connectivity.
• Contents: (To be filled)

Joint (0x60)

• Description: Stores joint data for skeletal animation.
• Contents: (To be filled)

JointName (0x61)

• Description: Contains names of joints for animation and rigging purposes.
• Contents: (To be filled)

CollisionPrism (0x100)

• Description: Defines collision prisms used in physics calculations.
• Contents: (To be filled)

CollisionGrid (0x110)

• Description: Contains data for collision grids, used for spatial partitioning.
• Contents: (To be filled)

EndOfFile (0xFFFF)

• Description: Marks the end of the MOD file.
• Contents: (To be filled)

Additional Notes

• Alignment ensures optimal performance with the GameCube and Wii, where aligned data loads quicker as they directly fall onto cache lines.