MDL0 (File Format)

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Revision as of 20:08, 8 October 2018 by NintenHero (talk | contribs) (Explaned what 0x04 of the Layers section means.)
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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. Always 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 if 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.
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 typically).
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 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 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 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 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 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 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 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 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, one 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 Unknown texture 2. 0xff typically.
0x02 1 Unknown texture 3. 0x0 typically.
0x03 1 Unknown texture 4. 0x1 typically.
0x04 48 Texture matrix (float4x3).
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 Palette offset, used as link into section 12.
0x08 4 Unknown. 0x0 typically.
0x0c 4 Unknown. 0x0 typically.
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.

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 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:

All about BRRES files

BRRES file — Index Group — Sub Files

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

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