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Swatch textures (.pb and .swatchbin)

ForzaTechTexturesApplies toFH6

A texture is a Grub bundle holding a TXCB blob with the mip chain, whose TXCH metadata is the PC texture content header. Track textures are .pb files named <name>_<guid>_qualityN.pb (some use a short id instead of a GUID, such as _bclr_tupfjgh); shared engine textures are .swatchbin entries in zips. Observed A texture’s game path is game:\media\<rel>\<name>_<guid>.swatchbin, which is what material parameters hash (Materials). Observed The SourceHash of the track’s asset manifest is the same hash. Proven

A texture bundle holds exactly one blob, TXCB, with exactly one metadata record, TXCH version 0. Proven · every texture of the install The TXCB blob’s version names the header: 0.0 the PC header below, 2.0 the Durango (Xbox One) header. Proven · every texture of the install

The install (build 25588841) holds 318,129 textures: 169,351 .pb in GeoChunk0 to GeoChunk3, all PC, and in its zips 22,251 .pb and 126,527 .swatchbin, of which 148,767 are PC and 11 are Durango (all .swatchbin in WeatherTextures.zip). The file extension does not tell the container: a zip holds both. Every one of them reads under the rules below with no refusal and no byte of any header unaccounted for. Proven · all 318,129 textures

Section titled “Header”
TXCH metadata (PC)variableFH694% known

Offsets are from the start of the TXCH metadata. Little-endian. The header ends exactly after the last mip record.

ProvenObservedSourcedInferredUnknownNot described
OffsetSizeTypeFieldConfidenceNotes
0x04u32 = 0x38slice list offsetProven
0x44u32first mip record linkProventhe offset of the first mip record plus 4
0x816u8[16]guidProvena Windows GUID; the (last) GUID in the file name when the name holds one, on 219,951 of the 220,008 textures whose name holds one; 54 of the other 57 (car scene textures in five car zips) hold 00000000-0000-0000-0000-000000000001 and the last 3 (the test*_diff swatches of DefaultTextures and a cinematic library) all hold 25C29A40-AA32-4334-933F-DC8EB3D663A0
0x184u32widthProven
0x1C4u32heightProven
0x204u32depthProven1, or the number of layers every mip holds (9, 60 and 128 occur); it does not shrink from mip to mip
0x242u16slice countProven1, the array size or 6 for a cube; at most 128
0x261u8mip countProven
0x271u8flagsObserved0, 1, 4, 5 or 6; bit 0 set only on 6-slice textures
0x284u32transcodingProven0 on every texture
0x2C4u32second colour profileUnknownequal to the colour profile at 48 on every texture
0x304u32colour profileProven0 linear, 1 sRGB; selects the sRGB DXGI format where one exists
0x344u32address modeObserved0 on every texture of a zip; 0 or 1 on the GeoChunk .pb (1 on 98,049 of 169,351)
0x384u32 = 0x40slice list offset againProven
0x3C4u32 = 0x44slice list linkProven
0x4012 per slicebytesslice recordsProven{ u32 encoding, u32 offset of the slice's first mip record, u32 next slice record offset + 4 or 0xFFFFFFFF on the last }
after the slice records12 per mip per slicebytesmip recordsProven{ u32 size, u32 offset into the TXCB data, u32 next mip record offset + 4 or 0xFFFFFFFF on the very last }; one list runs through every slice, largest mip first

The slice count is a whole u16: bits 14 and 15 are 0 on every texture (no platform bits). Proven · all 318,118 PC textures A mip record’s size is the bytes its format needs for that level, times the depth: max(1, width >> level) by max(1, height >> level) pixels, a block-compressed level a whole number of 4 × 4 blocks and at least one. Proven · every mip of every slice of all 318,118 PC textures The mips follow one another in the TXCB data with nothing between, from offset 0 to the end of the data, slice by slice. Proven · all 318,118 PC textures An independent reading of where the mips lie, ForzaTools.TexConv’s DDS writer read back by BCnEncoder.Net (which takes each mip’s size from the DXGI format alone), gives the same bytes for every mip of a sample of textures of depth 1. Observed · a sample of PC textures Flag bit 0 is set only on textures of 6 slices (cube maps), and not on every texture of 6 slices. Proven · all 318,118 PC textures Whether the other flag bits mean “premultiplied” or anything else is not established. Unknown

The pixel format is the first slice’s encoding, and it is sRGB only when the colour profile is 1. Proven · every PC texture; the same formats as ForzaTools and Doliman’s tables

Encoding Format DXGI (linear / sRGB)
0 BC1 71 / 72
1 BC2 74 / 75
2 BC3 77 / 78
3 / 4 BC4 UNORM / SNORM 80 / 81
5 / 6 BC5 UNORM / SNORM 83 / 84
7 / 8 BC6H UF16 / SF16 95 / 96
9 BC7 98 / 99
10 / 11 / 12 R32G32B32A32 float / R16G16B16A16 UNORM / R16G16B16A16 float 2 / 11 / 10
13 R8G8B8A8 28 / 29
14 / 15 B5G6R5 / B5G5R5A1 85 / 86
19 / 20 R8 / A8 61 / 65

Counted by the first slice’s encoding, the 318,118 PC textures are: BC7 212,892; BC1 30,374; BC4 UNORM 26,382 and SNORM 5,344; BC5 UNORM 14,035 and SNORM 2,583; R8 8,955; R16G16B16A16 float 6,618 and UNORM 935; BC6H UF16 5,064; R8G8B8A8 4,860; A8 51; BC3 19; BC2 4; R32G32B32A32 float 2. No slice of any texture has an encoding of 16 to 18, 21 or 22 (the reader refuses them), and no texture’s first slice is BC6H SF16, B5G6R5 or B5G5R5A1. Proven · all 318,118 PC textures Sources list 21 as R8G8 and 22 as a high-quality BC7 encode; neither occurs in this install. Sourced · ForzaTools Transcoding 1 (“BcBlockRle”) exists in the enum but no PC texture uses it. Proven · all 318,118 PC textures

The address mode (offset 52) over the 169,351 GeoChunk .pb textures is 0 (wrap) for 71,302 and 1 (clamp) for 98,049, and 0 on all 148,767 PC textures of the zips (.pb or .swatchbin); mode 2 never occurs. Proven · all 318,118 PC textures Clamp is on the per-cell terrain maps (mainmap_*, submap_*, autouberglossmap_*, whose half-texel border makes neighbouring cells share edge texels) and on most ub_* far-LOD swatches; tiling surfaces, detail maps, normal maps and swatch-tint palettes are wrap. Observed Whether the run-time sampler of every slot honours the texture’s own mode is not established; materials also carry sampler-state parameters. Unknown

Durango header

Section titled “Durango header”

A texture whose TXCB blob is version 2.0 has a 35-byte TXCH payload: the GUID (16 bytes), the base mip’s width and height (u16 each), the slice count (u16), the full texture’s width and height (u16 each), a u16, the mip count, the full mip count and the base mip (u8 each), and a u32 of bit fields. Proven · the 11 Durango textures of the install The bit fields are the console tile mode (bits 0 to 4; 13 on all 11), the encoding (5 to 10), the transcoding (11 to 16; 0) and the colour profile (20 to 22). Proven · the 11 Durango textures of the install The payload is tiled for the console, and where each mip lies in it is not stored in the file. Observed

Quality tiers

Section titled “Quality tiers”

The quality tiers _qualityN are the same image at different sizes (q1 smallest, up to q5 for terrain cell maps); every texture has at least its q1 tier in GeoChunk0. Observed A texture id in other files is PVSTextureIndex << 4 | (quality − 1). Observed

Sampling rules

Section titled “Sampling rules”

A shader reads a texture according to its stored format: *_SRGB formats are converted from sRGB to linear by the GPU, all others are read raw. A decoder keeps each texture’s format and picks the colour space from it, not from what the slot is used for. Observed BC4 and BC5 SNORM have signed endpoints (−127..127 → −1..1, D3D palette rules, −128 clamps to −127); decoding them as UNORM corrupts the data (the environment deposit maps are BC4 SNORM). Observed

Several data maps are sRGB (Mask_MetalnessATexture, ubershader_default_roughnessmetala, the road roadmodneutral modulate); the projection_lod *_rough maps are BC5 SNORM. Filtering happens after the per-texel decode on the GPU, which differs from filtering an 8-bit sRGB image first by up to 0.29 at a 0/1 edge of a metal mask and up to 0.07 for colour. Observed

Formats with no 8-bit path (BC6H HDR emissive maps and lightmaps, R16G16B16A16) are in use by the game; BC6H carries the emissive and lightmap data. Observed

Normal maps

Section titled “Normal maps”

Every family except snow decodes a tangent-space normal map the same way:

x = 2·s.r − 1,  y = 2·s.g − 1,  z = sqrt(saturate(1 − x² − y²))        blue and alpha are not normal data
n = T·x − B·y + N·z,   B = cross(N, T) · T.w                           N, T = normalised world normal and tangent

s is the sampled value, so a SNORM map gives x = 2v − 1 on the signed value. Observed On the game’s meshes T = +dP/du and cross(N, T) × w = +dP/dv, with D3D’s v pointing down the image (73,176 triangles of 242 meshes, 99.6% agree); so −B·y makes green+ point to the top of the image: the maps are Y+ (“OpenGL”), and green is not inverted. Observed Two independent checks agree: a MikkTSpace tangent frame built from the mesh UVs on 1,997 real triangles puts green as stored a median 0.03° from the game’s normal against 34° inverted; and of the 209 Tokyo normal maps where a curl-free test is decisive, 197 are Y+ and 12 Y−. Observed

snow reads its normal map raw (normalize(s.rgb) in tangent space, no 2v − 1): its shipped map averages (0.5, 0.5, 1), which tilts every normal about 35° toward T + B. Observed

Placeholder and default textures

Section titled “Placeholder and default textures”

The data contains textures that stand in for missing art. Markers: near-uniform images in a saturated colour (red, green, magenta, olive, cyan), images of 8 px or less, and names containing default, testb, flat, placeholder, debug or missing. Early road dashes and facade dashes of the Tokyo map were such placeholders; the red ubershader_default_diffusea on road decals is the default of the TerrainGlossTexture slot (0xAE91CDD4), a wetness and gloss map that never reaches the colour in dry weather. Observed The engine’s neutral modulate texture greyscale_grey128 has RGB 127/255, which is a brightness and saturation shift of 0.002, below one 8-bit step. Observed A window glass default is #2A3038. Inferred

The default of an unset normal-map slot is a SNORM map whose texels all hold the neutral normal. Over the Shibuya Scramble box, four BC5 SNORM textures are bound to a normal-map slot of the environment, environment_plot, environment_signage, glass, environmentdeferreddecal, window_linecastroom and uber_roaddecal families, and none holds a negative texel. Observed The 32 × 32 TriPlanarNormalTexRef default has one value in all 1,024 texels (the decoded bytes are 191 and 192, signed +0.498 and +0.506), so x = 2v − 1 is −0.004 and y is +0.012: a flat normal. Observed The 16 × 16 default of the NormalHeightTexture slot has bytes 184 to 198 (red) and 186 to 196 (green), so 2v − 1 lies within ±0.11 and its mean is 0.499: close to flat, but not one value. Observed The 128 × 128 default of the Blend2TextureSet slots has bytes 151 to 231, so 2v − 1 reaches ±0.63: it is a detailed normal map, not a flat default. Observed All four store only the positive half of the signed range, which fits the read 2v − 1: a negative v would give a component below −1. Inferred

215 texture paths referenced by car materials are in no archive of the install (referenced 396 times from materials of 142 cars: mostly badge and symbol labels, car_standard alpha, normal and roughness maps, interior LOD maps, the pg_hatchback_lip_ao back normal of seven lamp lenses); what the engine binds for a missing texture is run-time only. Observed In the world, 81 distinct texture hashes of the Tokyo core are in no archive (festival banners, flags, projection-LOD textures). Observed

Other texture containers

Section titled “Other texture containers”

Livery decals (media\Livery\Decals.zip: 270 BC7 sRGB decalNNN.swatchbin, DecalsHiRes.zip: 188) and livery masks (2,048 × 1,024 BC4 UNORM per region in each car archive) use the same container. Observed The pause-map tiles are 1,024 px swatches (The map). Observed

What does the second colour profile field mean?

Offset 44 equals the colour profile at offset 48 on every PC texture, so no texture says what it would be if it differed; only the profile at 48 selects a format.