Materials (Metroid Prime 3)

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Revision as of 23:24, 14 May 2015 by >Aruki (→‎Material Set Format)
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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 Flags Only bottom 17 bits are valid
0x4 u32 4 Group index Denotes groups of materials that share the same settings, but different textures.
0x8 u32 4 Unknown Value is possibly unused; the material loading code seems to skip it
0xC u32 4 Vertex attribute flags Functionality is identical to Metroid Prime 2
0x10 u32 4 Unknown Value is possibly unused; the material loading code seems to skip it
0x14 u32 4 Unknown
0x18 u32 4 Unknown
0x1C End of header

Flags

Known flag values:

Bit Hex Description
0 0x1 Unknown
1 0x2 Unknown
2 0x4 Unknown
3 0x8 Enable punchthrough alpha
4 0x10 Unknown
5 0x20 Enable additive blending (probably - needs verification)
6 0x40 Unknown
7 0x80 Unknown
8 0x100 Unknown
9 0x200 Shadow occluder mesh; meshes using this material are not rendered, but can be used to cast dynamic shadows on actors (it's either this or bit 8)
10 0x400 Unknown
11 0x800 Unknown

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

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 Unknown 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 animations size Needs verification; only bottom 8 bits are valid

List of possible PASS subtypes:

Type Description
DIFF Lightmap
BLOL Bloom lightmap
CLR Diffuse map
TRAN Greyscale opacity map; white indicates transparent, black indicates opaque (Retro is backwards)
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

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
DIFB

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