Swatchbin Viewer

The Swatchbin Viewer page lets you open, inspect, and export .swatchbin and .pb texture files used throughout the Forza titles. It handles both PC format textures and Xbox (Durango) format textures, and can batch-convert Xbox tiles to a PC-compatible bundle.

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Opening Files

• Drag and drop one or more supported files directly onto the page.
• Click the Open button in the toolbar to browse.

Supported Input Types

Type	Description
.swatchbin	Single-texture Grub bundle containing one TXCB texture blob
.pb	Multi-texture Grub bundle (Packed Bundle). Same binary format as .swatchbin but may contain multiple TXCB blobs. Each blob is split out into a separate viewer entry automatically
.zip	Standard ZIP archive. Any .swatchbin entries are extracted individually. Any .pb entries are parsed and split per texture blob
.minizip	Playground MiniZip (PGZP) streaming archive. Entries with resource type Texture (type code 5) use the .pb extension. All texture bundles are extracted and each TXCB blob is added as a separate viewer entry
Forza asset bundle	Any raw Grub bundle file containing one or more TextureContentBlob (TXCB) blobs

When an archive or bundle with multiple textures is opened the viewer extracts each texture to a temporary directory and populates the texture selector dropdown at the top of the page.

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Texture Selector

If more than one texture was loaded, a ComboBox at the top lets you switch between them. Each entry shows a generated display name:

• If the texture blob carries an IdentifierMetadata tag, the name is tex_0x<id-hex>.
• If a TextureContentHeader is present and contains a GUID, the name is tex_<guid>.
• Otherwise the name falls back to tex00, tex01

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Info Panel

The right-hand panel displays the parsed texture metadata:

Field	Description
Texture ID	GUID from the TextureContentHeader (PC) or Durango header, or blank if absent
Dimensions	Width, Height, Depth
Mip Levels	Number of mip levels stored in the file
Encoding	Block-compression or uncompressed pixel format (see table below)
DXGI Format	Numeric DXGI format code and its name string
Color Profile	Linear, sRGB, or other colour space hint
Flags	Texture Cube, 3D Texture, Premultiplied Alpha
Bundle Version	Major.Minor of the enclosing Grub bundle
Blob Version	Major.Minor of the TXCB blob version 1.x = PC, version 2.x = Xbox/Durango

Encoding Formats

Code	Name	Description
0	BC1	DXT1, opaque or 1-bit alpha, 4 bpp
1	BC2	DXT3, explicit 4-bit alpha, 8 bpp
2	BC3	DXT5, interpolated alpha, 8 bpp
3	UnsignedBC4	Single-channel unsigned, 4 bpp
4	SignedBC4	Single-channel signed, 4 bpp
5	UnsignedBC5	Two-channel unsigned (normal maps), 8 bpp
6	SignedBC5	Two-channel signed, 8 bpp
7	UnsignedBC6H	HDR unsigned half-float, 8 bpp
8	SignedBC6H	HDR signed half-float, 8 bpp
9	BC7	High-quality RGBA, 8 bpp
10	R32G32B32A32Float	128 bpp uncompressed float
11	R16G16B16A16	64 bpp uncompressed half
12	R16G16B16A16Float	64 bpp float
13	R8G8B8A8	32 bpp uncompressed
14	B5G6R5	16 bpp no alpha
15	B5G5R5A1	16 bpp 1-bit alpha
16	DCT	Discrete Cosine Transform (lossy)
17	IntegerDCT	Integer DCT variant
18	Procedural	Procedurally generated, no raw pixel data

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Viewport

The decoded texture is rendered in the central image viewer:

Action	Control
Pan	Left mouse button + drag
Zoom	Scroll wheel
Reset view	Double-click

The zoom level is shown in the status bar. The viewer preserves the aspect ratio and uses nearest-neighbour scaling by default.

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Platform Detection: PC vs. Xbox (Durango)

The viewer automatically detects the texture platform from the TXCB blob version:

• Blob version 1.x - PC format. Pixel data is stored linearly and can be decoded or exported directly.
• Blob version 2.x - Durango / Xbox format. Pixel data is stored in a GPU-specific tiled layout. The viewer calls the native xg.dll (shipped with ForzaTech Studio) to detile the texture before display.

Durango Tile Metadata

Xbox textures carry extra tiling fields in their TextureContentHeader:

Field	Description
Tile Mode	XG tile mode constant (e.g. XG_TILE_MODE_2D_THIN_1)
Tile Relative Mip Levels	How many mip levels are physically tiled
Tile Relative Dimensions	Width, Height, Depth as stored in the tiled surface

The detile pipeline uses xg.dll (XGComputeTextureLayout) to compute the exact per-mip memory layout, then copies each mip from the tiled buffer to a linear DDS layout.

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Export

Export as DDS

Saves the raw pixel data with a standard DDS header built from the texture metadata. The exported file can be opened in tools such as DirectXTex texconv, Paint.NET (with the DDS plugin), or GIMP.

Note: Xbox format textures are automatically detiled before export. The exported DDS is always in linear (PC) layout.

Export as PNG

Decodes the block-compressed data to RGBA8 using the BCnEncoder library and saves as a 24- or 32-bit PNG. Supported for all BC1-BC7 formats. HDR and float formats are tone-mapped to 8-bit.

Xbox to PC Conversion (Save as Swatchbin)

The Convert to PC button (shown only for Durango format files) runs the full conversion pipeline:

1. Detile the tiled pixel data via xg.dll.
2. Dealign row pitches to match linear DDS layout.
3. Build a new DDS byte array.
4. Re-encode the result back into a PC-format Grub bundle (TXCB blob version 1.x).
5. Save as a .swatchbin file.

The output file can be dropped directly into a car ZIP archive and referenced by the game engine.

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The .pb Texture Bundle Format

A .pb file (Packed Bundle) is a Grub bundle using exactly the same container format as .swatchbin, .modelbin, and all other ForzaTech gruB files. The only meaningful difference from a .swatchbin is that a .pb can contain more than one TXCB texture blob, making it a multi-texture bundle in a single file.

Where .pb Files Are Found

.pb files appear in two main locations:

• Inside .minizip streaming archives - MiniZip entries with resource type code 5 (Texture) use the .pb extension. These archives are the chunk-based world streaming format used by Forza Horizon titles (see the Create Zip page for MiniZip details). The viewer detects Grub bundle magic bytes on any entry whose type is not explicitly .swatchbin or .pb, so it can also surface texture bundles in entries without names.
• Inside standard .zip car archives - A single .pb file inside a car zip can carry multiple textures that would otherwise each require their own .swatchbin. This is common for track and environment texture sets.

How the Viewer Handles .pb Files

Because a single .pb can hold several independent textures, the viewer always splits it on load:

1. The bundle is parsed and all TXCB blobs are enumerated.
2. Each blob is wrapped in its own minimal Grub bundle and written to a temporary .swatchbin file on disk.
3. Each temporary file is added to the texture selector as a separate entry, labelled with the source file name and the per-blob texture identifier (GUID or hash ID if present, otherwise a sequential index).

This means a .pb containing four textures appears as four distinct entries in the selector, each with its own info panel and export options. The temporary files are cleaned up automatically when the page is navigated away from or the application closes.

Identifying the Texture Name

The name assigned to each extracted entry follows the same priority as a regular .swatchbin:

1. If the blob carries an IdentifierMetadata tag, the name is tex_0x<id-hex>.
2. If the TextureContentHeader contains a GUID, the name is tex_<guid>.
3. Otherwise the name falls back to tex00, tex01, etc.

The source file name is prepended in square brackets so you can tell which .pb or archive the texture came from, for example [GeoChunk0.minizip] entry_0012.pb tex_0x1A3F9C00.

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File Format Reference

A .swatchbin file is a Grub bundle (the same container format used by .modelbin, and other asset types). The bundle wraps a single TextureContentBlob (TXCB tag 0x54584342), which carries:

• A TextureContentHeader metadata entry (TXCH tag) containing all dimension, format, and platform-specific fields.
• An optional IdentifierMetadata entry, a 32-bit hash ID used by the asset pipeline.
• The raw pixel data as the blob payload.

A .pb file uses the same structure but can contain multiple TXCB blobs in sequence within one bundle.

[Bundle Header]  magic "Grub" (0x47727562)  VersionMajor / VersionMinor
    TXCB Blob  (VersionMajor 1=PC, 2=Durango)
        TXCH Metadata  (dimensions, format, tile info, GUID)
        IDEN Metadata  (optional 32-bit hash)
        Pixel Data     (tiled on Xbox, linear on PC)
    [TXCB Blob]  (additional blobs present only in .pb files)
    ...