CMDL (Tropical Freeze)

See CMDL (File Format) for the other revisions of this format.

Tropical Freeze features a new model format (necessitated by the hardware jump from Wii to Wii U) that bears little-to-no resemblance to the CMDL format of past games. There are three extensions used for models:

• CMDL: Generic models
• SMDL: Skinned models (ie. animated characters)
• WMDL: World models (ie. level geometry)

All three share the same basic format, with SMDL and WMDL each containing an extra data chunk at the start of the file.

This file format needs more research There's a lot of unknown data.

Format

File layout:

Type/Name	Notes
Form Descriptor	Form ID is CMDL, SMDL, or WMDL.
Skinned Model Header	Only present in SMDL files
World Model Header	Only present in WMDL files
Model Header
Material Data
Render Meshes
Vertex Buffers
Index Buffers
GPU Data

Skinned Model Header

Offset	Type	Count	Name	Notes
0x0	Chunk Descriptor	1	SKHD Chunk Descriptor	Data type is SKHD
0x18	u32	1	Unknown
0x1C	End of Skinned Model Header

World Model Header

Type	Count	Name	Notes
Chunk Descriptor	1	WDHD Chunk Descriptor	Chunk ID is WDHD
u8	1	Unknown
Render Octree	1	Render Octree
u32	1	Unknown AABox Count
AABox	Unknown AABox Count	Unknown AABox Array
u32	1	Unknown Float Count
float	Unknown Float Count	Unknown Float Array

Render Octree

This seems to be an updated version of the AROT format seen in previous Retro games.

Offset	Type	Count	Name	Notes
0x0	FourCC	1	Magic	Always AROT (Area Octree)
0x4	u32	1	Unknown	Always 1. Version number?
0x8	u32	1	Unknown
0xC	u32	1	Unknown
0x10	u32	1	Unknown
0x14	AABox	1	Octree Bounding Box	Bounds of the entire octree; matches the bounding box from the main model header.
0x2C	u32	1	Unknown Count A
0x30	u32	Unknown Count A	Unknown Array A
	u32	1	Unknown Count B
	u8	Unknown Count B	Unknown Array B
	u32	1	Unknown AABox Count
	AABox	Unknown AABox Count	Unknown AABox Array

Model Header

Offset	Type	Count	Name	Notes
0x0	Chunk Descriptor	1	HEAD Chunk Descriptor	Chunk ID is HEAD
0x18	u32	1	Unknown
0x1C	u32	1	Unknown
0x20	u32	1	Unknown
0x24	u32	1	Unknown
0x28	u32	1	Unknown
0x2C	AABox	1	Model Bounding Box
0x44	u32	1	Model Data Source Count
0x48	Model Data Source	Model Data Source Count	Model Data Source Array

Model Data Source

Offset	Type	Name	Notes
0x0	u32	Model Data Source Type	Controls the type of data present in this data source. Valid values are 0, 1, 2, or 3.
0x4		Model Data Source Data	Structure and size varies depending on Model Data Source Type. See below.

Type 0: UV Animation

To do: Needs research. The loader function doesn't reveal much because the game just loads all the data into a couple big buffers.

Type 1: Wind

Type	Count	Name	Notes
u32	1	Wind Set Count	Count of Wind Set elements in the next array.
Wind Set	Wind Set Count	Wind Set Array
u32	1	Unknown Count
u8	Unknown Count	Unknown Data

Wind Set

Offset	Type	Name	Notes
0x0	Vector3f	Unknown
0xC	Vector3f	Unknown
0x18	float	Unknown
0x1C	End of Wind Set

Type 2: Caustic

Type	Count	Name	Notes
u32	1	Unknown Count
u32	Unknown Count	Unknown Array

Type 3: Fur

Type	Count	Name	Notes
u32	1	Unknown Count A
float	Unknown Count A	Unknown Array A
u32	1	Unknown Count B
float	Unknown Count B	Unknown Array B
u32	1	Unknown Count C
float	Unknown Count C	Unknown Array C

Material Data

The MTRL section has a 32-bit material count, then lays out its materials one after the other. Materials are composed of basically a MTRL asset ID which contains the shader the material is rendered with, then per-instance material parameters (textures, scalar/color parameters, etc).

Type	Count	Name	Notes
string	1	Material Name	Zero-terminated string
Asset ID (MTRL)	1	Material Shader Asset ID	Points to the MTRL file containing the shader for this material.
FourCC	1	Material Type	Can be PHNG (Phong), LAMB (Lambert), SURF (Surface), FURM (Fur), or REFL (Reflect). REFL may be unused.
u32	1	Material Flags	Bitfield used to toggle various settings on the material. None of the flags are known.
u32	1	Parameter Count	Count of parameters in this material definition.
Material Parameter	Parameter Count	Parameter Array

Material Parameter

Each parameter has a fourCC parameter ID as well as a parameter type enum. There are five possible parameter types that each have a different layout in the file.

Offset	Type	Count	Name	Notes
0x0	FourCC	1	Parameter ID
0x4	u32	1	Parameter Type	Determines what type of data this parameter contains. Can be either 0, 1, 2, 4, or 5. (Note: 3 is an invalid value, not an unused type.)
0x8			Parameter Data	Structure and size varies depending on Parameter Type. See below.

Type 0: Texture Token Data

Offset	Type	Count	Name	Notes
0x0	Asset ID (TXTR)	1	Texture ID	Texture asset ID.
0x10	Texture Usage Info	1	Texture Usage Info	Note: Not present if the TXTR asset ID is invalid.
End of Texture Token Data

Type 1: Color Data

Offset	Type	Count	Name	Notes
0x0	Color4f	1	Color Value
0x10	End of Color Data

Type 2: Scalar Data

Offset	Type	Count	Name	Notes
0x0	float	1	Scalar Value
0x4	End of Scalar Data

Type 4: Layered Texture Data

Offset	Type	Count	Name	Notes
0x0	u32	1	Unknown
0x4	Color4f	1	Unknown Color
0x14	Color4f	1	Unknown Color
0x24	Color4f	1	Unknown Color
0x34	u8	1	Unknown
0x35	Texture Token Data	1	Unknown Texture Token Data
	Texture Token Data	1	Unknown Texture Token Data
	Texture Token Data	1	Unknown Texture Token Data
End of Layered Texture Data

Type 5: Int4 Data

Offset	Type	Count	Name	Notes
0x0	u32	4	Int4 Value
0x10	End of Int4 Data

Texture Usage Info

Offset	Type	Count	Name	Notes
0x0	u32	1	Unknown
0x4	u32	1	Unknown
0x8	u32	1	Unknown
0xC	u32	1	Unknown
0x10	u32	1	Unknown
0x14	End of Texture Usage Info

Render Meshes

The MESH section defines render meshes.

Type	Count	Name	Notes
Chunk Descriptor	1	MESH Chunk Descriptor	Chunk ID is MESH
u32	1	Render Mesh Count
Render Mesh	Render Mesh Count	Render Mesh Array

Render Mesh

Offset	Type	Count	Name	Notes
0x0	u32	1	Unknown	Always 3?
0x4	u16	1	Material Index
0x6	u8	1	Vertex Buffer Index
0x7	u8	1	Index Buffer Index
0x8	u32	1	Start Index	This is basically an offset into the selected index buffer.
0xC	u32	1	Index Count	Number of indices for this mesh in the index buffer.
0x10	u32	1	Unknown
0x14	bool	1	Unknown
0x15	End of Render Mesh

Vertex Buffers

The VBUF section defines vertex buffers; each buffer can have different vertex types, with different strides and attributes.

Type	Count	Name	Notes
Chunk Descriptor	1	VBUF Chunk Descriptor	Chunk ID is VBUF
u32	1	Vertex Buffer Count
Vertex Buffer	Vertex Buffer Count	Vertex Buffer Array	The model will contain a separate vertex buffer for every unique vertex configuration needed.

Vertex Buffer

Type	Count	Name	Notes
u32	1	Vertex Count	Number of vertices in the buffer.
u32	1	Vertex Component Count	Number of components in each vertex.
Vertex Component	Vertex Component Count	Vertex Component Array	Definitions for each component in the vertex.

Vertex Component

Offset	Type	Count	Name	Notes
0x0	u32	1	Unknown
0x4	u32	1	Offset	Offset of this component within the vertex.
0x8	u32	1	Stride	Distance in bytes between elements of this component within the vertex buffer. (This is equivalent to the full size of a single vertex.)
0xC	u32	1	Unknown
0x10	u32	1	Unknown	Likely component type/format
0x14	End of Vertex Component

Index Buffers

Just like how the VBUF section defines vertex buffers, the IBUF section defines index buffers. Each index buffer only has one value associated with it, so it's fairly simple, and you generally will only see one or two index buffers per file (as there's only two possible index buffer configurations).

Type	Count	Name	Notes
Chunk Descriptor	1	IBUF Chunk Descriptor	Chunk Descriptor is IBUF
u32	1	Index Buffer Count
Index Buffer	Index Buffer Count	Index Buffer Array

Index Buffer

Offset	Type	Name	Notes
0x0	u32	Format	1 means unsigned short; 2 means unsigned long.
0x4	End of Index Buffer

GPU Data

The GPU section contains raw buffer data that's fed to the GPU. It's essentially just a giant blob with all the vertex and index buffers laid out next to each other. The tricky part is, all the buffer data is LZSS-compressed, and the metadata needed to decompress it is stored in the pak rather than in the files themselves; not only that, but that metadata is also the only way to distinguish the different buffers from each other.

As such, this section can't be read correctly if the model file is unpacked and completely left as-is; it needs to be either read directly from the pak, or the metadata needs to be added to the file in some way. A good unpacker should append the metadata to the end of the file; a pre-decompressed file needs the buffer sizes or offsets inserted into the file data somewhere.

PAK Metadata

The PAK metadata for the model formats contains mainly information related to the size and layout of the GPU section, and the metadata required to locate and decompress specific buffers within it.

Type	Count	Name	Notes
u32	1	Unknown	Always 4?
u32	1	GPU Section Offset
u32	1	Read Buffer Count	Number of read buffers making up the GPU section.
Read Buffer Info	Read Buffer Count	Read Buffer Array	Definitions for each read buffer.
u32	1	Vertex Buffer Count	Number of vertex buffers in the model.
Buffer Info	Vertex Buffer Count	Vertex Buffer Info Array	Array containing all data needed to decompress each vertex buffer.
u32	1	Index Buffer Count	Number of index buffers in the model.
Buffer Info	Index Buffer Count	Index Buffer Info Array	Array containing all data needed to decompress each index buffer.

Read Buffer Info

For large models, the GPU section may be split into multiple read buffers. All offsets into the GPU section will be relative to the beginning of the chosen buffer.

Offset	Type	Name	Notes
0x0	u32	Size	Size of the buffer.
0x4	u32	Offset	Offset of the buffer within the GPU section.
0x8	End of Read Buffer Info

Buffer Info

This structure is used for both vertex and index buffers.

Offset	Type	Name	Notes
0x0	u32	Read Buffer Index	The read buffer that this buffer is inside of.
0x4	u32	Start Offset	Starting offset of this buffer, relative to the start of the chosen read buffer.
0x8	u32	Compressed Size	Size of the compressed data.
0xC	u32	Decompressed Size	Size of the data after being decompressed.
0x10	End of Buffer Info