MDL0 (File Format)

This page describes the Mario Kart Wii MDL0 file format, as found within BRRES files.

File Format

File Header

Offset	Type	Description
0x00	String	The magic "MDL0" to identify the sub file. See »BRRES Sub Files« for other magics.
0x04	UInt32	Length of the sub file.
0x08	UInt32	Sub file version number. The number of sections (N) is dependent of this version number. See »BRRES Sub Files« for details.
0x0C	Int32	Offset to outer BRRES File.
0x10	Int32[N]	N section offsets. N is implied in the version number (offset 0x08).
0x10+N*4	Int32	String offset to the name of this sub file. This name equal to the name of the entry name of the BRRES Index Group pointing to this data.
0x14+N*4	End of this header

• All offsets are relative to the start of the header.
• MKW uses MDL0 v11 with (N=) 14 sections.
• The section offsets point to BRRES Index Group structures for the directories, which in turn point to the actual data sections within the MDL0 file.
• Sections are linked by names. The names are stored in a common string pool for all BRRES sub files. MDL0 itself stores only 32-bit offsets into the common string pool.

The meaning of each section is defined by numbers as below:

Section	description
0	Draw lists
1	Bones
2	Vertices
3	Normals
4	Colors
5	Texture coordinates
6	Fur vectors (seen in v10+ MDL0's)
7	Fur layers (seen in v10+ MDL0's)
8	Materials
9	TEV's (shader-like operations)
10	Objects (Polygons)
11	Texture links
12	Palette links (Not seen in Mario Kart Wii)
13	Unknown (not seen in Mario Kart Wii or v9 MDL0's)

MDL0 header

Following the section offsets there is a MDL0 header structure.

Offset	Size	Description
0x00	4	Header length (0x40)
0x04	4	File header offset
0x08	4	Unknown
0x0C	4	Unknown
0x10	4	Vertex count
0x14	4	Face count
0x18	4	Unknown
0x1C	4	Bone count
0x20	4	Unknown (0x01000000)
0x24	4	Bone table offset
0x28	12	Minimum (float3)
0x34	12	Maximum (float3)

All offsets are relative to the start of the header.

Bone-link table

The bone-link table usually follows directly after the MDL0 header. However, its offset also lies within the header. The table below describes how the IDs of bone sections are related to their indices. If the Wii needs a specific bone, it looks up the ID from this table, and then, it loads the bone from the index given.

Offset	Size	Description
0x00	4	Entry count
0x04	4 * Entry count	Node index (-1 for not present)

notes:
If a model has 5 bones, and 9 weights, and bones 0 and 3 do not affect geometry the block would look like this:

00000001 00000002 00000004 FFFFFFFF
FFFFFFFF FFFFFFFF FFFFFFFF 00000000
00000003

So the weights with one bone affecting geometry come first, then the weights with multiple influences (all as 0xFFFFFFFF), and finally the weights for joints with no geometry.

The indexes in the Nodemix block will match up to the weights' position here, and the 0x10 block in a joint will be the index of its weight as it appears here (so the value of 0x10 in joint 0 above would be 0x00000007).

BRRES Index Group

Following the bone-link table, one BRRES Index Group for each non empty section is defined. The sections in the MDL0 header link to the groups.

Section order

In Mario Kart Wii we can find some old (unused) v8 MDL0 files (old_mario_gc_*.szs; 11 sections) and v11 (the rest of them; 14 sections).

The v8 MDL0 files use sections 0–9, but not 10. The general section order is: 9, 0, 1, 6, 7, 8, 2, 3, 4, 5. All the v11 ones use sections 0–5 and 8–11, but not 6, 7, 12 and 13. The general order here is 11, 0, 1, 8, 9, 10, 2, 3, 4, 5.

If creating a new v11 MDL0 file, it is recommended to use this section order: 11, 0, 1, 6, 7, 8, 9, 10, 2, 3, 4, 5. The order of sections 12 and 13 is unknown.

Section formats

Section 0 - Draw Lists

The draw list format is poorly understood. It is known to control the fundamentals of how things are rendered, and in a specified order. It is used to link polygons to materials. The format is simply a series of command bytes followed by a variable amount of parameters. Known commands are listed below.

Code	Parameters bytes							Description
	00	01	02	03	04	05	06
0x01	None							End of commands. Keep reading until encountered.
0x02	Weight index		Parent weight index		None			Bone mapping
0x03	Weight ID		Weight count	Table ID		weight * 4 bytes		Weighting
0x04	Object index		Material index		Bone index		Unknown	Draw polygon. Draws polygon
0x05	Weight ID		Weight index		None			Indexing

Section 1 - Bones

The bone files are used to describe the structure of polygons within the model, in order to allow character animations. It is also used in Mario Kart Wii by map_model.brres to describe the map placement in courses. It is still not completely understood.
The bones obey a tree structure, using the parent, first child, next child and previous child offsets to point to other bones in the tree. Most files have their first bone named the same as the entire MDL0 file, and having no transformation, and they use child bones to perform transformations. 0 means no bone for these offsets.

Offset	Size	Description
0x00	4	Length of data structure (0xD0)
0x04	4	MDL0 offset
0x08	4	Name offset
0x0C	4	Index
0x10	4	ID
0x14	4	Unknown flags (0x31f typical)
0x18	4	Billboard setting 0x0000 = None. 0x0001 = Influenced by rotation of the parent node. The z-axis direction is parallel to the camera lens axis. 0x0002 = Influenced by rotation of the parent node. The z-axis direction points toward the camera direction. 0x0003 = Not influenced by the rotation of the parent node and restricted by the camera's Up vector. The z-axis direction is parallel to the camera lens axis. 0x0004 = Not influenced by the rotation of the parent node and restricted by the camera's Up vector. The z-axis direction points toward the camera direction. 0x0005 = Influenced by the rotation of the parent node and rotates only around the y-axis. The z-axis direction is parallel to the camera lens axis. 0x0006 = Influenced by the rotation of the parent node and rotates only around the y-axis. The z-axis direction points toward the camera direction.
0x1C	4	Padding
0x20	12	A 3D scaling vector (float3).
0x2C	12	A 3D rotation vector (float3, Euler rotation in degree).
0x38	12	A 3D translation vector (float3).
0x44	12	Minimum (float3), not always set.
0x50	12	Maximum (float3), not always set.
0x5C	4	Parent offset
0x60	4	First Child offset
0x64	4	Next Sibling offset
0x68	4	Previous Sibling offset
0x6C	4	Part 2 offset
0x70	48	Transformation matrix, 12 floats organized in 3 rows with 4 column values. It is a clockwise/left-handed rotation with Euler angles and x-y-z convention. A fourth matrix line is assumed to be always "0 0 0 1", but not stored. The matrix can be calculated by Scale (0x20), Rotation (0x2c) and Translation (0x38). All tests to modify the matrix had not any impact. It seems, that the matrix is calculated after loading.
0xA0	48	This is the Inverse matrix of Transformation matrix (0x70), organised in the same way. Again, the fourth matrix line is assumed to be always "0 0 0 1" without storing the data. All tests to modify the matrix had not any impact. It seems, that the matrix is calculated after loading.

All offsets are relative to the start of the file.

Section 2 - Vertices

The vertex section contains information of the vertices in the model. Each polygon specifies which vertex group is it going to use, and indexes the items within.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Data offset
0x0C	4	Name offset
0x10	4	Index
0x14	4	Component count Enum Size Description 0x0 Format*2 XY position 0x1 Format*3 XYZ position
0x18	4	Format (data type) Format Stride Description 0x0 0x3 u8 0x1 0x3 s8 0x2 0x6 u16 0x3 0x6 s16 0x4 0xc float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	1	Divisor
0x1D	1	Stride
0x1E	2	Vertex count
0x20	12	Minimum (float3)
0x2C	12	Maximum (float3)

All offsets are relative to the start of the file.
After the header, at the data offset (0x40 typical) there is vertex data.

Section 3 - Normals

The normal section contains information of the normals in the model. Each polygon specifies which normal group is it going to use, and indexes the items within.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Data offset
0x0C	4	Name offset
0x10	4	Index
0x14	4	Component count Enum Size Description 0x0 Format*3 Normal 0x1 Format*9 Normal Bi-normal Tangent 0x2 Format*3 Normal or Bi-normal or Tangent
0x18	4	Format (data type) Format Stride Description 0x0 0x3 u8 0x1 0x3 s8 0x2 0x6 u16 0x3 0x6 s16 0x4 0xc float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	1	Divisor
0x1D	1	Stride
0x1E	2	Normal count

All offsets are relative to the start of the file.
After the header, at the data offset (0x20 typical) there is normal data.

Section 4 - Colors

The color section contains information of the colors in the model. Each polygon specifies which color group(s) is it going to use, and indexes the items within.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Data offset
0x0C	4	Name offset
0x10	4	Index
0x14	4	Component count Enum Size Description 0x0 Format (0, 1, or 2) RGB color 0x1 Format (3, 4, or 5) RGBA color Both component types can range in byte sizes from 2 to 4.
0x18	4	Format Format Stride Description Red Green Blue Alpha 0x0 0x2 RGB565 5 bits 6 bits 5 bits – 0x1 0x3 RGB8 (RGB24) 8 bits 8 bits 8 bits – 0x2 0x4 RGBX8 (RGBX32) X values discarded. 8 bits 8 bits 8 bits 8 bits (ignored) 0x3 0x2 RGBA4 (RGBA16) 4 bits 4 bits 4 bits 4 bits 0x4 0x3 RGBA6 (RGBA24) 6 bits 6 bits 6 bits 6 bits 0x5 0x4 RGBA8 (RGBA32) 8 bits 8 bits 8 bits 8 bits
0x1C	1	Stride
0x1D	1	Unknown
0x1E	2	Color count

All offsets are relative to the start of the file.
After the header, at the data offset (0x20 typical) there is color data.

Section 5 - Texture coordinates

The texture coordinate section contains information of the texture UV coordinates in the model. Each polygon specifies which texture coordinate group(s) is it going to use, and indexes the items within.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Data offset
0x0C	4	Name offset
0x10	4	Index
0x14	4	Component count Enum Size Description 0x0 Format*1 S coord 0x1 Format*2 ST coord
0x18	4	Format (data type) Format Stride Description 0x0 0x2 u8 0x1 0x2 s8 0x2 0x4 u16 0x3 0x4 s16 0x4 0x8 float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	1	Divisor
0x1D	1	Stride
0x1E	2	Texture coordinate count
0x20	8	Minimum (float2)
0x28	8	Maximum (float2)

All offsets are relative to the start of the file.
After the header, at the data offset (0x40 typical) there is texture coordinate data.

Section 6 - Fur vectors

(Seen in "smallbard.mdl0" v11 (Ridley's pre-mature form) from Super Smash Bros. Brawl).

This section is assumed to draw fur bases on vectors at specific points on the model's surface.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Data offset
0x0C	4	Name offset
0x10	4	Index
0x14	2	Texture coordinate count
0x16	10	Padding (possible unknown values)

Following this there are (float3) vectors.

Section 7 - Fur layers

This section is assumed to contain the shelling vectors for the fur vectors section which is assumed to be used to draw a line-strip from each vector.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Data offset
0x0C	4	Name offset
0x10	4	Index
0x14	4	Component count
0x18	4	Format (data type) Format Stride Description 0x0 0x2 u8 0x1 0x2 s8 0x2 0x4 u16 0x3 0x4 s16 0x4 0x8 float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	1	Divisor
0x1D	1	Stride
0x1E	2	Vector count
0x20	12	Minimum (float3)
0x2C	12	Maximum (float3)

Layering info:

Offset	Size	Description
0x00	4	Layer count
0x04	4	Layer size
0x08	24	Padding (possible unknown values)

Following this there is layer-vector data ( data_type * vector_count * layer_count ) NOTE: The layer's size may mean there's padding in some cases.

Actual tests for these fur sections have not been performed yet. It is unsure if the vector positioning here is local to the fur vectors (like normals), or globally oriented.

Section 8 - Materials

The material section contains information about the texturing of models. The draw list commands specify which polygons are linked to which materials.

The following table describes the general layout of MDL0 v11 section 8. All Mario Kart Wii files use exactly this layout:

Size	Description
0x418	Basic data structure. The first 32 bit value is the size of the complete section.
N * 0x34	N * layer data. N is a 32 bit number in the range 0 to 6 read from 'base+0x2c'. The start offset is stored at 'base+0x30' and is 0 (if N is 0) or 0x418 for all Mario Kart Wii files.
0..0x1c	Alignment to a multiple of 0x20 (relative to MDL file start) for the next field.
0x180	Setup Code. The start offset is stored at 'base+0x3c'.

Basic data structure

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Name offset
0x0C	4	Index (0..0x1e)
0x10	4	XLU-Material (0x0 for disabled or 0x80000000 for enabled)
0x14	1	Texgens
0x15	1	Light channels
0x16	1	Shader stages
0x17	1	Indirect textures
0x18	4	Cull-mode
0x1C	1	Alpha function
0x1D	1	Lightset
0x1E	1	Fogset
0x1F	1	Unknown (always 0)
0x20	4	Unknown (always 0)
0x24	4	Unknown (always 0xffffffff)
0x28	4	Shader offset
0x2C	4	Amount of textures
0x30	4	Layer offset
0x34	4	Part 2 offset
0x38	4	Display list offset 8_9
0x3c	4	Display list offset 10_11
0x40	360	Unknown (always 0)
0x1a8	4/8*4	4 bit layer flags value; 1 for each layer with the msb containing the last layer. Bit (lsb = 0) 2 Description 0 Enable layer 1 Scale fixed 2 Rotation fixed 3 Translation fixed
0x1ac	4	Unknown Flags
0x1b0	20 * 8	8 copies of the following structure Offset Size Description 0x00 8 Scale coordinate (float2) 0x08 4 Rotation coordinate (float) 0x0C 8 Translation coordinate (float2)
0x250	52 * 8	Texture matrix - 8 copies of the following structure Offset Size Description 0x00 1 Unknown texture 1 (0xff typically) 0x01 1 Unkown texture 2 (0xff typically) 0x02 1 Unkown texture 3 (0x0 typically) 0x03 1 Unknown texture 4 (0x1 typically) 0x04 48 float4x3 Texture matrix
0x3f0	4	Unknown flags (0x3f typically)
0x3f4	36	Lightings Offset Size Description 0x00 4 Color0Color 0 0x04 4 Color0Color 1 0x08 2 Padding 0x0a 2 Color0Enums 0 and 1 0x0c 2 Padding 0x0e 2 Color0Enums 2 and 3 0x10 4 Unknown flags 0x14 4 Color0Color 0 0x18 4 Color0Color 1 0x1c 2 Padding 0x1e 2 Color0Enums 0 and 1 0x20 2 Padding 0x22 2 Color0Enums 2 and 3

All offsets are relative to the start of the file.

Layers

Normally immediately after this data there is layer information. It is at the layer offset. Each layer information structure is described as below.

Offset	Size	Description
0x00	4	Name offset; used as link into section 11
0x04	4	Unknown (0x0 typical)
0x08	4	Unknown (0x0 typical)
0x0c	4	Unknown (0x0 typical)
0x10	4	Layer 1
0x14	4	Layer 2
0x18	4	X texture address settings
0x1c	4	Y texture address settings
0x20	4	MinFilter, 00 05 is used to load smaller mipmaps the further ahead the texture is.
0x24	4	MagFilter
0x28	4	LOD bias
0x2c	4	Maximum anisotropy filtering. Can improve texture quality, but not recommended to use on many materials. Can be 00 00 for one, 00 01 for two and 00 02 for four times anisotropic filtering.
0x30	1	Clamp bias, true (1) or false (0).
0x31	1	Texel interpolate, true (1) or false (0).
0x32	2	Unknown (0x0 typically)

All offsets are relative to the start of the layer section.
The X and Y texture settings values are given below.

Settings	Description
0x0	Clamp
0x1	Repeat
0x2	Mirror

Shader

Always after the layer information (and padding to 0x20) there is shader data, directly at its offset. This is Wii Graphics Code which describes how the material is created. It is split down into four basic sections.

Offset	Size	Description
0x000	0x20	Mode information
0x020	0x80	Tev regs
0x0a0	0x40	Texture transformations
0x0e0	0xa0	Texture matrices
0x180	End of shader

Section 9 - TEV's

This section has information about how the color and texture informations are combined in the Wii's GPU. Each material has a link to a TEV structure. Several materials often share the same TEV. The structure is often referenced many times in the index group too. Most large MDL0's may only have three or four structures, but many more appear in the file tree due to repeats. The repeats always ensure that each material has a structure with the same name, which it links to.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Index
0x0c	1	Layer count (material flag)
0x0d	1	Res0 (0x0 typically)
0x0e	1	Res1 (0x0 typically)
0x0f	1	Res2 (0x0 typically)
0x10	1 * 8	[TRef0:TRef7] (0x0 typically, 0xff for unused layers)
0x18	8	Padding

All offsets are relative to the start of the file.
After this section follows Wii Graphics Code, which describes how information is transformed into colors by the graphics card. The length of this code is Length - 0x20.

Section 10 - Objects (Polygons)

The objects section describes how vertex data is combined optionally with colors, texture coordinates and normals, as well as bones and materials in order to produce the rendered model.

Offset	Size	Description
0x00	4	Length
0x04	4	MDL0 offset
0x08	4	Bone index (for single bone references) (-1 for table usage)
0x0c	4	CP_Vtx (0x4400 typically)
0x10	4	CP_Tex (0x2 typically)
0x14	4	XF_Nor_Spec (0x11 typically)
0x18	4	Vertex declaration size (0xe0)
0x1c	4	Unknown flags (0x80 typically)
0x20	4	Vertex declaration offset (0x68 typically)
0x24	4	Vertex data size
0x28	4	Vertex data size
0x2c	4	Vertex data offset (0x13c typically)
0x30	4	XF_Flags (0x2a00 typically)
0x34	4	Unknown (0x0 typically)
0x38	4	Name offset
0x3c	4	Index
0x40	4	Vertex count
0x44	4	Face count
0x48	2	Vertex group index
0x4a	2	Normal group index
0x4c	2 * 2	2 color group indices
0x50	2 * 8	8 texture coordinate group indices
0x60	4	Unknown (-1 typically) (Not seen in version 9 MDL0's)
0x64	4	Bone table offset

All offsets are relative to the start of the file, except the vertex declaration and vertex data offsets. The vertex declaration offset is relative to 0x20, itself. The vertex data offset is relative to 0x24.
Normally directly after the header, there is a bone table, at its offset. This table is only used in objects which use multiple bones, and therefore have -1 value in their bone offset field. The use of this table is still not fully understood.

Offset	Size	Description
0x00	4	Entry count
0x04	2 * Entry count	Bone ID

After the bone table there is vertex declaration. This is Wii Graphics Code which describes the format of each vertex in the polygon. This is at the vertex declaration offset.
After the vertex declaration there is vertex code. This is Wii Graphics Code which describes how the model is rendered. It contains commands such as triange drawing. The indices of the points are also here.

Section 11 - Texture links

There is one texture link section for each texture used in the model. Each section contains a table with links (offset values) into material sections. These section has no names.

Offset	Size	Description
0x00	4	Entry count
0x04	8 * Entry count	Entry count copies of the following structure: Offset Size Description 0x00 4 Offset relative to section start into a material section (#8). 0x04 4 Offset relative to section start into a material layer. The layer is part of the material section above.

All offsets are relative to the start of the file.

Tools

The following tools can handle MDL0 files:

• BrawlBox, by Kryal & BlackJax
• CTools, by Chadderz
• SZS Modifier, by Chadderz
• Wiimms SZS Tools, By Wiimm

All about BRRES files

BRRES file — Index Group — Sub Files

CHR0 — CLR0 — MDL0 — PAT0 — SCN0 — SHP0 — SRT0 — TEX0