MDL0 (File Format)

Overview

This article 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.
• Mario Kart Wii 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	User Data. 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	UInt32	Header length (0x40).
0x04	Int32	File header offset.
0x08	UInt32	Scaling Mode Value Description 0x0 Standard 0x1 SoftImage 0x2 Maya
0x0C	UInt32	Texture Matrix Mode Value Description 0x0 Maya 0x1 XSI 0x2 3ds Max
0x10	Int32	Vertex count.
0x14	Int32	Face count.
0x18	Int32	Unused. Offset to absolute path of intermediate file.
0x1C	UInt32	Matricies count.
0x20	Byte	Requires normalized matricies array if not 0.
0x21	Byte	Requires texture matrices array if not 0.
0x22	Byte	Enable bounding volume data if not 0.
0x23	Byte	Unknown. Padding?
0x24	Int32	Offset to matricies table.
0x28	Float[3]	Bounding volume minimum.
0x34	Float[3]	Bounding volume maximum.

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 game needs a specific bone, it looks up the ID from this table, and then loads the bone from the index given.

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

If a model has five bones and nine 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

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

The indices 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 and 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	Length	Parameters bytes									Description
		00	01	02	03	04	05	06	07	08
0x00	0x1	None									No operation.
0x01	0x1	None									End of commands. Keep reading until encountered.
0x02	0x5	Bone index		Parent matrix index		None					Node mapping.
0x03	0x4+0x6*N	Weight ID		N + Weight count	Table ID		N * Weight				Weighting.
0x04	0x8	Object index		Material index		Bone index		Priority	None		Draw polygon.
0x05	0x5	Matrix ID		Weight index		None					Indexing.
0x06	0x5	To matrix		From matrix		None					Duplicate matrix.

Section 1 - Bones

The bone files are used to describe the structure of polygons within the model, in order to allow CHR0 animations. It is also used in Mario Kart Wii by map_model.brres to describe the map placement in courses.

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. 0 means no bone for these offsets.

Offset	Size	Description
0x00	UInt32	Length of data structure (0xD0).
0x04	Int32	MDL0 offset.
0x08	Int32	Name offset.
0x0C	UInt32	Index.
0x10	UInt32	ID.
0x14	UInt32	Flags. Bit f e d c b a 9 8 Meaning Unused Is a Child of Billboard Bone Is Display Matrix Is Visible Bit 7 6 5 4 3 2 1 0 Meaning Disable Classic Scale Apply Child Scale Compensate Apply Scale Compensate Scale Uniform Scale Isotropic Rotation Isotropic Translation Isotropic Use Identity
0x18	UInt32	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	UInt32	Billboard transformation of this bone if parent is a Billboard bone.
0x20	Float[3]	A 3D scaling vector
0x2C	Float[3]	A 3D rotation vector (in degrees).
0x38	Float[3]	A 3D translation vector.
0x44	Float[3]	Bounding volume minimum.
0x50	Float[3]	Bounding volume maximum.
0x5C	Int32	Parent offset.
0x60	Int32	First Child offset.
0x64	Int32	Next Sibling offset.
0x68	Int32	Previous Sibling offset.
0x6C	Int32	User Data offset.
0x70	MTX34	Transformation matrix, 12 floats organized in 3 rows with 4 column values. It is a clockwise Rotation matrix with Euler angles and x-y-z convention. A fourth matrix line is assumed to always be "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 did not have any impact. It seems, that the matrix is calculated after loading.
0xA0	MTX34	This is the Inverse matrix of Transformation matrix (0x70), organised in the same way. Again, the fourth matrix line is assumed to always be "0 0 0 1" without storing the data. All tests to modify the matrix did not have 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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Data offset.
0x0C	Int32	Name offset.
0x10	UInt32	Index.
0x14	UInt32	Component count. Enum Size Description. 0x0 Format*2 XY position. 0x1 Format*3 XYZ position.
0x18	UInt32	Format (data type): Format Stride Description 0x0 0x3 UInt8 0x1 0x3 Int8 0x2 0x6 UInt16 0x3 0x6 Int16 0x4 0xc Float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	Byte	Divisor.
0x1D	Byte	Stride.
0x1E	UInt16	Vertex count.
0x20	Float[3]	Bounding volume minimum.
0x2C	Float[3]	Bounding volume maximum.

All offsets are relative to the start of the file.
After the header, at the data offset (0x40 typically) 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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Data offset.
0x0C	Int32	Name offset.
0x10	UInt32	Index.
0x14	UInt32	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	UInt32	Format (data type): Enum Stride Description 0x0 0x3 UInt8 0x1 0x3 Int8 0x2 0x6 UInt16 0x3 0x6 Int16 0x4 0xc Float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	Byte	Divisor.
0x1D	Byte	Stride.
0x1E	Uint16	Normal count.

All offsets are relative to the start of the file. After the header at the data offset (0x20 typically) 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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Data offset.
0x0C	Int32	Name offset.
0x10	UInt32	Index.
0x14	UInt32	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	UInt32	Format Enum 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	Byte	Stride.
0x1D	Byte	Padding.
0x1E	UInt16	Color count.

All offsets are relative to the start of the file. After the header at the data offset (0x20 typically) 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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Data offset.
0x0C	Int32	Name offset.
0x10	UInt32	Index.
0x14	UInt32	Component count. Enum Size Description 0x0 Format*1 S coord. 0x1 Format*2 ST coord.
0x18	UInt32	Format (data type): Enum Stride Description 0x0 0x2 UInt8 0x1 0x2 Int8 0x2 0x4 UInt16 0x3 0x4 Int16 0x4 0x8 Float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	Byte	Divisor.
0x1D	Byte	Stride.
0x1E	UInt16	Texture coordinate count.
0x20	Float[2]	Bounding volume minimum.
0x28	Float[2]	Bounding volume maximum.

All offsets are relative to the start of the file. After the header at the data offset (0x40 typically) 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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Data offset.
0x0C	Int32	Name offset.
0x10	UInt32	Index.
0x14	UInt32	Fur Vector count.

Following this, there are (float3) vectors.

Section 7 - Fur Layer Positions

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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Data offset.
0x0C	Int32	Name offset.
0x10	UInt32	Index.
0x14	UInt32	Component count. Enum Size Description. 0x0 Format*2 XY position. 0x1 Format*3 XYZ position.
0x18	UInt32	Format (data type): Format Stride Description 0x0 0x3 UInt8 0x1 0x3 Int8 0x2 0x6 UInt16 0x3 0x6 Int16 0x4 0xc Float For all formats except float, the value is divided by 2 ^ divisor.
0x1C	Byte	Divisor.
0x1D	Byte	Stride.
0x1E	UInt16	Vertex Count in fur layer.
0x20	UInt32	Number of fur layers.
0x24	UInt32	Offset to fur layer.

Following this there is layer-vector data (data_type * vector_count * layer_count). The layer's size may mean there is 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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Name offset.
0x0C	UInt32	Index.
0x10	UInt32	Material Flags. Axxxxxxx xxxxxxxx xxxxxxxx BCDEFGHI. A - XLU Material. B - Do not send texture matrix data. C - Do not send texture coordinate data. D - Do not send generator mode data. E - Do not send lighting channel data. F - Do not send indirect matrix data. G - Do not send texture coordinate scale data. H - Do not send TEV color data. I - Do not send pixel display data.
0x14	Byte	Texgens.
0x15	Byte	Light channels.
0x16	Byte	Shader stages.
0x17	Byte	Indirect textures.
0x18	UInt32	Culling. ID Description 0x0x None. 0x01 Front. 0x02 Back. 0x03 All.
0x1C	Byte	Depth test.
0x1D	Byte	Lightset Index.
0x1E	Byte	Fog Index.
0x1F	Byte	Padding.
0x20	Byte[4]	Indirect Method. ID Description 0 Wrap 1 Normal map 2 Normal map specular 3 Fur 4 Reserved 5 Reserved 6 User 0 7 User 1
0x24	Byte[4]	Light normal map reference, used by indirect stages.
0x28	Int32	Shader offset.
0x2C	UInt32	Amount of textures.
0x30	Int32	Layer offset.
0x34	Int32	Fur data offset. (version 10 and 11 MDL0s). User Data (version 8 and 9 MDL0s).
0x38	Int32	Display list offset (version 8 and 9 MDL0s). User Data (version 10 and 11 MDL0s).
0x3c	Int32	Display list offset (version 10 and 11 MDL0s).
0x40	UInt32	Bitflag. Used texture maps. Bit 0 (LSB) means texture map 0 is used, bit 1 - texture map 1 etc.
0x44	Byte[8][32]	Precompiled code space containing texture information.
0x144	UInt32	Bitflag. Used palletes. Bit 0 (LSB) means pallete 0 is used, bit 1 - pallete 1 etc.
0x148	Byte[8][12]	Precompiled code space containing palette information.
0x1a8	UInt32	Bit flag. Bit Description 0 Enable layer. 1 Scale fixed. 2 Rotation fixed. 3 Translation fixed.
0x1ac	UInt32	Texture matrix mode Value Description 0 Maya 1 XSI 2 3DS Max
0x1b0	20 * 8	8 copies of the following structure: Offset Size Description 0x00 Float[2] Scale coordinate. 0x08 Float Rotation coordinate. 0x0C Float[2] Translation coordinate.
0x250	52 * 8	Texture matrix - 8 copies of the following structure: Offset Size Description 0x00 SByte SCN0 camera reference 0x01 SByte SCN0 light reference 0x02 Byte Map mode: Value Description 0 Texture coordinates 1 EnvCamera 2 Projection 3 EnvLight 4 EnvSpec 0x03 Byte Enable identity matrix effect 0x04 MTX34 Texture matrix.
0x3f0	20 * 2	Lighting channels: Offset Size Description 0x00 UInt32 Flags Bit Description 0 Material color enabled. 1 Material alpha enabled. 2 Ambient color enabled. 3 Ambient alpha enabled. 4 Raster color enabled. 5 Raster alpha enabled. 0x04 RGBA Material color. 0x08 RGBA Ambient color. 0x0c UInt32 Color light channel control. 0x10 UInt32 Alpha light channel control.

All offsets are relative to the start of the file.

Texture References

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	Int32	Name offset, used as link into section 11.
0x04	Int32	Palette name offset, used as link into section 12.
0x08	Int32	Texture data offset.* 0x0 typically.
0x0c	Int32	Palette data offset.* 0x0 typically.
0x10	UInt32	Texture data ID, indexes an entry in the texture information list.
0x14	UInt32	Palette data ID, indexes an entry in the palette information list.
0x18	UInt32	U texture wrapping mode.
0x1c	UInt32	V texture wrapping mode.
0x20	UInt32	Minification texture filtering. Enum Description 0x00 Nearest 0x01 Linear 0x02 Nearest Mipmap Nearest 0x03 Linear Mipmap Nearest 0x04 Nearest Mipmap Linear 0x05 Linear Mipmap Linear
0x24	UInt32	Magnification texture filtering. Enum Description 0x00 Nearest 0x01 Linear
0x28	Float	LOD bias.
0x2c	UInt32	Max Anisotropy filtering. Can improve texture quality, but not recommended to use on many materials. Enum Description 0x00 One 0x01 Two 0x02 Four
0x30	Byte	Clamp bias.
0x31	Byte	Texel interpolate.
0x32	Byte[2]	Padding.

• These offsets are calculated by the game during track load, whether or not non-zero values are kept is unknown.

Wrapping modes

Settings	Description
0x0	Clamp.
0x1	Repeat.
0x2	Mirror.

Fur Data

This section appears right after the texture references only if a material uses fur.

Offset	Type	Description
0x00	Float	Maximum length to which fur can grow.
0x04	UInt32	Number of fur layers.
0x08	UInt32	Type of spacing between fur layers. Enum Description 0x0 Uniform interval. 0x1 More dense at tips.
0x0C	Float	Alpha curvature parameter.
0x10	Float	Specular lighting curvature parameter.

Shader

After the layer information (and padding to 0x20), there is always shader data directly at its offset. This is the 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 color regs.
0x0a0	0x40	Indirect texture transformations.
0x0e0	0xa0	Texture matrices.
0x180	End of shader.

Section 9 - TEVs

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	UInt32	Length.
0x04	Int32	MDL0 offset.
0x08	Int32	Index.
0x0C	Byte	TEV Stage Count.
0x0d	Byte[3]	Padding.
0x10	Byte[8]	[TexScale0:TexScale7] (0xff for unused references). Indices to a material layer.
0x18	Byte[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. Normally those commands control color and alpha blending, indirect texture mapping and color channel swapping.

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 a value of -1 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 the 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 also the Wii Graphics Code, which describes how the model is rendered. It contains commands such as triangle 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 sections have 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.

Section 12 - Palette Links

There is one palette link section for each palette used in the model. Each section contains a table with links (offset values) into material sections. These sections also have 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.
• BrawlCrate, by soopercool101.
• CTools, by Chadderz.
• SZS Modifier, by Chadderz.
• Wiimms SZS Tools, by Wiimm.

Links

All about BRRES files

BRRES file — Index Group — Sub Files

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