Materials (Metroid Prime 3)

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Revision as of 23:09, 17 May 2015 by >Aruki (→‎PASS: Previewing is a good idea)
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The format for materials saw a dramatic overhaul in Metroid Prime 3. The format is seen in both the CMDL and MREA formats and is identical in both. This particular material format appears in Metroid Prime 3: Corruption and Donkey Kong Country Returns.


This file format needs more research
Need to find TEV values for each subsection type


Material Set Format

Materials come as part of a set; although most files will only have one set, some CMDLs will have more, as indicated by a count value in the header. The set format is merely a 32-bit count value followed by that number of materials.

Material Format

The material format starts with a 28-byte header, then after that is broken up into a bunch of subsections.

Header

Offset Type Size Description Notes
0x0 u32 4 Material size Does not include size value
0x4 u32 4 Material flags Only bottom 17 bits are valid
0x8 u32 4 Group index Denotes groups of materials that share the same settings, but different textures.
0xC u32 4 Unknown Value is possibly unused; the material loading code seems to skip it
0x10 u32 4 Vertex attribute flags Functionality is identical to Metroid Prime 2
0x14 u32 4 Unknown Value is possibly unused; the material loading code seems to skip it
0x18 u32 4 Unknown
0x1C u32 4 Unknown
0x20 End of header

Flags

Known flag values:

Bit Hex Description
0 0x1 Unknown
1 0x2 Unknown
2 0x4 Unknown
3 0x8 Unknown
4 0x10 Unknown
5 0x20 Enable additive blending (probably - needs verification)
6 0x40 Unknown
7 0x80 Unknown
8 0x100 Shadow occluder mesh; meshes using this material are not rendered, but can be used to cast dynamic shadows on actors
9 0x200 Unknown
10 0x400 Unknown
11 0x800 Unknown
12 0x1000 Unknown
13 0x2000 Unknown
14 0x4000 Unknown
15 0x8000 Unknown
16 0x10000 Unknown
17+ - Unused

Subsections

The rest of the material data is made up of a number of subsections. These subsections generally set different texture slots, as well as other parameters like Konst colors and material opacity. There's no count for the number of subsections; it needs to be read in using a while loop. The "END " section denotes the end of the material.

The order of the subsections doesn't matter. One material can only have one of each type of subsection; if there's any additional ones, they will overwrite the previous ones.

There are three subsection types (aside from END): PASS, CLR, and INT. Each of these types has a number of subtypes.

PASS

The PASS sections set up a single rendering pass, consisting of one TEV stage and potential other data to go with it (like a UV animation). One pass is 32 bytes (without the animation) and is structured as follows:

Offset Type Size Description Notes
0x0 u32 4 PASS subsection size
0x4 char[4] 4 Section subtype fourCC See below for possible subtypes
0x8 u32 4 Pass Flags Only bottom 5 bits are valid
0xC TXTR 8 Texture ID
0x14 u32 4 UV Source Only bottom 4 bits are valid
0x18 u32 4 UV Animation Size

If there's a UV anim, it is structured like this:

Offset Type Size Description
0x0 u16 2 Unknown
0x2 u16 2 Unknown
0x4 u32 4 Animation Type

List of possible PASS subtypes:

Type Description
DIFF Lightmap
BLOL Bloom lightmap
CLR Diffuse map
TRAN Greyscale opacity map
INCA Emissive map
RFLV Specular map
RFLD Reflection/sphere map
LRLD See RFLD
LURD See RFLV
BLOD See BLOL
BLOI See BLOL
XRAY Sphere map for X-Ray models; similar to RFLD
Flags

Known flag settings:

Bit Hex Description
0 0x1 Unknown
1 0x2 Unknown
2 0x4 Unknown
3 0x8 Unknown
4 0x10 On TRAN, indicates that the texture map is inverted (ie. white is transparent, black is opaque).
5+ - Unused

CLR

Offset Type Size Description Notes
0x0 char[4] 4 Section subtype fourCC See below for possible subtypes
0x4 u32 4 Color value 32-bit RGBA value

List of possible CLR subtypes:

Type Description
CLR Unknown
DIFB Lightmap multiplier color

INT

Offset Type Size Description Notes
0x0 char[4] 4 Section subtype fourCC See below for possible subtypes
0x4 u32 4 Value Actually an 8-bit value; the top 24 bits are ignored

List of possible INT subtypes:

Type Description
OPAC Sets the opacity of the entire material
BLOD
BLOI
BNIF
XRBR