Valve Texture Format

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The Valve Texture Format (VTF) is the proprietary texture format used by the Source engine. VTF files are generally referenced in a Material instead of being accessed directly, which allows re-use in different ways.

VTF files can be created from TGA images using the Source SDK Tool Vtex, or from most common image formats with third-party tools. Both textures and materials are stored in subfolders of game_dir/materials/.

Note.png Note: All block-compressed VTF files (such as those which use DXT compression) must have dimensions that are a multiple of 4. Although VTF dimensions are usually restricted to powers of two, some third-party tools can import and export non-powers of two textures. If you opt to use non-power-of-two textures, expect texture filtering to break (this can be "remedied" by setting the point sampling flag on the texture).
Tip.png Tip: It is possible, to an extent, to restore DXT compressed VTF files (i.e. removing compression artifacts) by using an AI.

Storage capabilities

The VTF image format can store either a flat texture, an environment map, or a volumetric texture. Each of these can have multiple frames.

  • Textures up to 4096x4096 pixels.
Note.png Note: Textures with dimensions larger than 4096 pixels can be created, if a few conditions are met. The resulting .vtf should be below 33 MB (or 33,554,432 bytes), the resolutions used is a powers of two and isn't exceeding 65,536 pixels in either dimension and the total amount of pixels of the image should be below 16.7 megapixels: For example, a texture the size of 512x32,768 will work, because 512 multiplied by 32,768 equals 16.7 megapixels.
  • An environment map is a six-faced cube map, unless the version is less than 7.5 and the first frame in the header is -1, then it will be seven-faced.
  • A volumetric texture is a texture with depth, where each frame is a "layer" which are layered in the third dimension. So a 16x16x16 volumetric texture has 16 separate 16x16 textures stacked to give depth. This format is used internally by Source, and you shouldn't have any need to actually create one yourself.
  • For each frame and face, the VTF file contains both the basic original source-image data (pixel map) and a series of mipmaps used for rendering the texture over varying distances. Because each successive mipmap is exactly 1/2 the dimension (height and width) of the previous one, the source-image dimensions must be a multiple of 4. Although the source-image may be rectangular, square mipmaps are stored more efficiently in the VTF.
  • Start frame (for animations)
  • Bump map scale
  • A Reflectivity value for use by VRAD
  • A very low resolution copy of the VTF for color sampling by the engine.


VTF 7.3 added an extensible "resource data" system. Anything can be added, but Source will recognise only the following:

  • A CRC value, for detecting data corruption.
  • An U/V LOD control. This is the highest mipmap which should be loaded when the game's Texture Detail setting is "High" (mat_picmip 0). An U LOD Control value of 11 will select the mipmap which is 2048 pixels (211) across at the "High" texture setting, and 4096 pixels across at the "Very High" (mat_picmip -1) texture setting.
    Note.png Note: Since users are currently only presented with one texture detail setting above High, there is little point setting this value to anything except 50% or 100% of your texture's size. Otherwise, the user would need to manually set theirmat_picmipto a lower value to see the full-res texture, like in Team Fortress 2, which requiressv_cheatsin most other titles.
  • Animated particle sheet data.
  • Expanded texture settings. This is a collection of 32 flags, none of which are in use by Valve. Unlike the built-in VTF flags these can be defined on a game-by-game basis.

Image data formats

The VTF image format can store image data in a variety of formats. Some formats were meant for the engine, some only as an interim format for conversions. The uncompressed formats are not lossy and the compressed (DXT) formats are.

Note.png Note: The VTF format can actually store many more formats than those listed below -- consult your engine branch's public/bitmap/imageformat.h to see exactly what it supports. However, these formats are not GUARANTEED to work and their enum values are prone to being shuffled around between engine branches.

Image data format table

Format Red Bits Green Bits Blue Bits Grey Bits Palette Bits Alpha Bits Total Bits Compressed Supported Comments
A8 0 0 0 N/A N/A 8 8 False True
ABGR8888 8 8 8 N/A N/A 8 32 False True Uncompressed texture with 8-bit alpha
ARGB8888 8 8 8 N/A N/A 8 32 False True
BGR565 5 6 5 N/A N/A 0 16 False True Uncompressed texture, limited color depth
BGR888 8 8 8 N/A N/A 0 24 False True Uncompressed texture
BGR888_BLUESCREEN 8 8 8 N/A N/A 0 24 False True
BGRA4444 4 4 4 N/A N/A 4 16 False True Uncompressed texture with alpha, half color depth
BGRA5551 5 5 5 N/A N/A 1 16 False True
BGRA8888 8 8 8 N/A N/A 8 32 Either True Compressed HDR texture with no alpha or uncompressed SDR texture with 8-bit alpha
BGRX5551 5 5 5 N/A N/A 1 16 False True
BGRX8888 8 8 8 N/A N/A 8 32 False True
DXT1 N/A N/A N/A N/A 4 0 4 True True Standard compression, no alpha
DXT1_ONEBITALPHA N/A N/A N/A N/A 4 1 4 True True Standard compression, 1-bit alpha
DXT3 N/A N/A N/A N/A 4 4 8 True True Standard compression, uninterpolated 4-bit Alpha
DXT5 N/A N/A N/A N/A 4 8 8 True True Standard compression, interpolated 8-bit alpha (recommended)
I8 N/A N/A N/A 8 N/A N/A 8 False True Luminance (Grayscale), no alpha
IA88 N/A N/A N/A 8 N/A 8 16 False True Luminance (Grayscale), 8-bit alpha
P8 N/A N/A N/A N/A 8 N/A 8 False False Paletted
RGB565 5 6 5 N/A N/A 0 16 False True
RGB888 8 8 8 N/A N/A 0 24 False True
RGB888_BLUESCREEN 8 8 8 N/A N/A 0 24 False True
RGBA16161616 16 16 16 N/A N/A 16 64 False True Integer HDR Format
RGBA16161616F 16 16 16 N/A N/A 16 64 False True Floating Point HDR Format
RGBA8888 8 8 8 N/A N/A 8 32 False True
UV88 8 8 N/A N/A N/A N/A 16 False True Uncompressed du/dv Format
UVLX8888 N/A N/A N/A N/A N/A N/A 32 False True
UVWQ8888 N/A N/A N/A N/A N/A N/A 32 False True
Comparison of how DXTn compression affects different types of images

HDR compression

HDR textures can be stored in compressed form using the BGRA8888 format.

The formula to convert these colors back to integer HDR is:

RGB = RGB * (A * 16)

and for floating point HDR:

RGB = (RGB * (A * 16)) / 262144

Additional data formats

These are additional image formats that are found in imageformat.h of Source 2013 Source 2013 and Alien Swarm engine branch Alien Swarm engine branch.

Formats found in Source 2013
Format Red Bits Green Bit Blue Bits Alpha Bits Total Bits Compressed Supported Comments
R32F 32 0 0 0 32 False ? Single-channel 32-bit floating point
RGB323232F 32 32 32 0 48 False ? 32-Bit Floating point HDR
RGB32323232F 32 32 32 32 64 False ? 32-Bit Floating point HDR w/alpha channel
Formats found in Alien Swarm engine branch
Format Red Bits Green Bit Blue Bits Alpha Bits Total Bits Compressed Supported Comments
RG1616F 16 16 0 0 32 False ? Dual-channel 16-bit floating point
RG3232F 32 32 0 0 64 False ? Dual-channel 32-bit floating point
RGBX8888 8 8 8 8 32 False ?
RGBA1010102 10 10 10 2 32 Either ? 10 bit-per component render targets
BGRA1010102 10 10 10 2 32 Either ? 10 bit-per component render targets
R16F 16 0 0 0 16 Either ? 16 bit floating point

Additionally, Portal 2: Community Edition Portal 2: Community Edition adds support for additional compression formats:

Formats found in Portal 2: Community Edition
Format Red Bits Green Bits Blue Bits Grey Bits Palette Bits Total Bits Compressed Supported Comments
ATI1N N/A N/A N/A N/A 4 4 True True AKA BC4, greyscale; Identical to alpha channel of DXT5
ATI2N N/A N/A N/A N/A 8 8 True True AKA BC5, Red and Green; equivalent to two ATI1N textures
BC6H N/A N/A N/A N/A 8 8 True True Block-compressed 16-bpc HDR textures; no alpha channel
BC7 N/A N/A N/A N/A 8 8 True True High-quality block compression; alpha channel optional
Hardware decoding requires DX11; converted to RGBA8888 in DX9 mode.

Choosing an image format

Though the VTF image format provides support for a wide range of image data formats, there are only a handful of image data formats you are likely to use. These formats and their criteria are described below:

  • BGR888: use this format for textures with no alpha channel and very fine gradients (i.e. normal maps or light halos).
  • BGRA8888: use this format for textures with an alpha channel and very fine gradients (i.e. normal maps or light halos). It can also be used to produce Very High quality textures.
  • DXT1: use this format for typical textures with no alpha channel. (Also known as BC1.)
Note.png Note: DXT1 supports 1 bit of alpha precision. However, any areas of 0 alpha will be fully black. This functionality is therefore best used for textures using $alphatest.
  • DXT3: DXT5 should almost always be used over DXT3, but DXT3 is acceptable (not necessarily better) for textures with an alpha channel with sharp gradients. (Also known as BC2.)
  • DXT5: use this format for typical textures with an alpha channel. (Also known as BC3).
  • I8: use this format for greyscale textures with no alpha channel and very fine gradients (i.e. light halos).
  • IA88: use this format for greyscale textures with an alpha channel and very fine gradients (i.e. smoke or light halos).
  • RGBA16161616F: use this format for HDR textures.
  • UV88: use this format for DuDv maps.

Find technical details on the various DXT compression formats here and here.

Image flags

Tip.png Tip: Most shader settings are configured as material parameters, not texture flags.

A VTF file can contain the following flags (version 7.5):

Flag Value Comment
Point Sampling 0x0001 Disable Bilinear filtering for "pixel art"-style texture filtering. (Does not work with mipmaps, see $pointsamplemagfilter if using Counter-Strike: Global Offensive CS:GO branch).
Trilinear Sampling 0x0002 Always use Trilinear filtering, even when set to Bilinear in video settings.
Clamp S 0x0004 Clamp S coordinates.
Clamp T 0x0008 Clamp T coordinates.
Anisotropic Sampling 0x0010 Always use Anisotropic filtering, even when set to Bilinear or Trilinear in video settings.
Hint DXT5 0x0020 Used in skyboxes. Makes sure edges are seamless.
PWL Corrected 0x0040 Purpose unknown.
SRGB n/a Uses space RGB. Useful for High Gamuts. Deprecated in 7.5.
No Compress 0x0040 No DXT compression used. Deprecated
Normal Map 0x0080 Texture is a normal map.
No Mipmaps 0x0100 Render largest mipmap only. (Does not delete existing mipmaps, just disables them.)
No Level Of Detail 0x0200 Not affected by texture resolution settings.
No Minimum Mipmap 0x0400 If set, load mipmaps below 32x32 pixels.
Procedural 0x0800 Texture is an procedural texture (code can modify it).
One Bit Alpha 0x1000 One bit alpha channel used.
Eight Bit Alpha 0x2000 Eight bit alpha channel used.
Environment Map 0x4000 Texture is an environment map.
Render Target 0x8000 Texture is a render target.
Depth Render Target 0x10000 Texture is a depth render target.
No Debug Override 0x20000 To do: Add description
Single Copy 0x40000 To do: Add description
Pre SRGB 0x80000 SRGB correction has already been applied
One Over Mipmap Level In Alpha 0x80000 Fill the alpha channel with 1/Mipmap Level. Deprecated (Internal to VTEX?)
Premultiply Color By One Over Mipmap Level 0x100000 (Internal to VTEX?)
Normal To DuDv 0x200000 Texture is a DuDv map. (Internal to VTEX?)
Alpha Test Mipmap Generation 0x400000 (Internal to VTEX?)
No Depth Buffer 0x800000 Do not buffer for Video Processing, generally render distance.
Nice Filtered 0x1000000 Use NICE filtering to generate mipmaps. (Internal to VTEX?)
Clamp U 0x2000000 Clamp U coordinates (for volumetric textures).
Vertex Texture 0x4000000 Usable as a vertex texture
SSBump 0x8000000 Texture is a SSBump. (SSB)
Border 0x20000000 Clamp to border colour on all texture coordinates

File format

The VTF image format is described as follows.

VTF layout

7.2 7.3 +
  1. VTF Header
  2. VTF Low Resolution Image Data
  3. For Each Mipmap (Smallest to Largest)
    • For Each Frame (First to Last)
      • For Each Face (First to Last)
        • For Each Z Slice (Min to Max; Varies with Mipmap)
          • VTF High Resolution Image Data
  1. VTF Header
  2. Resource entries
    • VTF Low Resolution Image Data
    • Other resource data
    • For Each Mipmap (Smallest to Largest)
      • For Each Frame (First to Last)
        • For Each Face (First to Last)
          • For Each Z Slice (Min to Max; Varies with Mipmap)
            • VTF High Resolution Image Data

VTF enumerations

enum CompiledVtfFlags
	// Flags from the *.txt config file

	// These are automatically generated by vtex from the texture data.

	// Newer flags from the *.txt config file
        TEXTUREFLAGS_UNUSED_00100000 = 0x00100000,
	TEXTUREFLAGS_UNUSED_00200000 = 0x00200000,
	TEXTUREFLAGS_UNUSED_00400000 = 0x00400000,


	TEXTUREFLAGS_UNUSED_01000000 = 0x01000000,

	TEXTUREFLAGS_SSBUMP = 0x08000000,			

	TEXTUREFLAGS_UNUSED_10000000 = 0x10000000,


	TEXTUREFLAGS_UNUSED_40000000 = 0x40000000,
	TEXTUREFLAGS_UNUSED_80000000 = 0x80000000,

VTF header

typedef struct tagVTFHEADER
    char            signature[4];       // File signature ("VTF\0"). (or as little-endian integer, 0x00465456)
    unsigned int    version[2];         // version[0].version[1] (currently 7.2).
    unsigned int    headerSize;         // Size of the header struct  (16 byte aligned; currently 80 bytes) + size of the resources dictionary (7.3+).
    unsigned short  width;              // Width of the largest mipmap in pixels. Must be a power of 2.
    unsigned short  height;             // Height of the largest mipmap in pixels. Must be a power of 2.
    unsigned int    flags;              // VTF flags.
    unsigned short  frames;             // Number of frames, if animated (1 for no animation).
    unsigned short  firstFrame;         // First frame in animation (0 based). Can be -1 in environment maps older than 7.5, meaning there are 7 faces, not 6.
    unsigned char   padding0[4];        // reflectivity padding (16 byte alignment).
    float           reflectivity[3];    // reflectivity vector.
    unsigned char   padding1[4];        // reflectivity padding (8 byte packing).
    float           bumpmapScale;       // Bumpmap scale.
    unsigned int    highResImageFormat; // High resolution image format.
    unsigned char   mipmapCount;        // Number of mipmaps.
    unsigned int    lowResImageFormat;  // Low resolution image format (always DXT1).
    unsigned char   lowResImageWidth;   // Low resolution image width.
    unsigned char   lowResImageHeight;  // Low resolution image height.

    // 7.2+
    unsigned short  depth;              // Depth of the largest mipmap in pixels. Must be a power of 2. Is 1 for a 2D texture.

    // 7.3+
    unsigned char   padding2[3];        // depth padding (4 byte alignment).
    unsigned int    numResources;       // Number of resources this vtf has. The max appears to be 32.

    unsigned char   padding3[8];        // Necessary on certain compilers

VTF Resource Entry

struct ResourceEntryInfo {
	unsigned char	tag[3]; 		// A three-byte "tag" that identifies what this resource is.
	unsigned char	flags;			// Resource entry flags. The only known flag is 0x2, which indicates that no data chunk corresponds to this resource.
	unsigned int	offset;			// The offset of this resource's data in the file. 
{ '\x01', '\0', '\0' } - Low-res (thumbnail) image data.
{ '\x30', '\0', '\0' } - High-res image data.
{ '\x10', '\0', '\0' } - Animated particle sheet data.
{ 'C', 'R', 'C' } - CRC data.
{ 'L', 'O', 'D' } - Texture LOD control information.
{ 'T', 'S', 'O' } - Game-defined "extended" VTF flags.
{ 'K', 'V', 'D' } - Arbitrary KeyValues data.

VTF lo-res image data

Tightly packed low resolution image data in the format described in the header. The low resolution image data is always stored in the DXT1 compressed image format. Its dimensions are that of the largest mipmap with a width or height that does not exceed 16 pixels. i.e. for a 256x256 pixel VTF: 16x16, for a 256x64 pixel VTF: 16x4, for a 1x32 pixel VTF: 1x16, for a 4x4 pixel VTF: 4x4.

VTF hi-res image data

Tightly packed interleaved high resolution image data in the format described in the header. Common image formats include DXT1, DXT5, BGR888, BGRA8888 and UV88. All dimensions must be a multiple of 4.

Version history

To do: Address game-specific compatibility issues


  • Incompatible with Half-Life 2 Half-Life 2, Counter-Strike: Source Counter-Strike: Source and Team Fortress 2 Team Fortress 2. Textures with VTF version 7.5 used by materials in those games need to be converted using a tool such as VTFVer. This is useful when e.g. mounting content from Counter-Strike: Global Offensive Counter-Strike: Global Offensive or Black Mesa Black Mesa into older games.
    • Common errors encountered when using VTFVer to convert Counter-Strike: Global Offensive textures to v7.4:
      • In some cases, an "Exception could not be handled" error manifests during texture conversion. It is not confirmed what causes this at the current time.
      • Additionally, some of Counter-Strike: Global Offensive envmap textures, such as materials/environment maps/metal_generic_xxx.vtf, fail to be converted properly and must be reconstructed in an older vtf version. This can be done by simple exporting as .tga and re-importing and saving as v7.4 or earlier.
  • Released July 19th, 2010 as part of Alien Swarm Alien Swarm.
  • Bitwise equivalent to v7.4.
  • Redefines and revises two texture flags.
  • Spheremaps now officially redundant.
  • Most changes internal to the VTF creation process with VTEX, e.g. MipMap fading, Alpha decay and Xbox 360 XBox360 formats.


  • Released October 10th, 2007 as part of The Orange Box.
  • Bitwise equivalent to v7.3.
  • Addresses issues related to how gamma-correction is performed on textures for TV-output on XBOX 360 combined with hunting down OS Paged Pool Memory.


  • Added an extensible resource orientated structure.
  • Added CRC, Texture LOD Control and Sheet resources, along with backwards compatible Image and Low Resolution Image resources.
  • Added several vendor specific depth-stencil formats (for internal engine use), along with normal map formats and linear uncompressed formats.
  • Released September 18th, 2007 as part of the Team Fortress 2 Team Fortress 2 beta.


  • Added volumetric texture support.
  • Released September 23rd, 2005 as a Steam engine update.


  • Added spheremap support to environment maps. (This was intended for DirectX 6 support which was later cut.)


  • Initial release. (Internal release only, though some v7.0 textures made it to the published title.)


An example Steam independent implementation of the VTF image file format can be found in the LGPL C/C++ library VTFLib.


Windows thumbnail handler (Windows XP+)
VTF Explorer (Windows; can explore inside GCFs)
gdk-pixbuf-vtf (Gnome\Nautilus\Eog)
IrfanView plugin
Leadworks Image Viewer [dead link] (supports VTF)
VTFEdit (GUI) and VTFCmd (command line)
Photoshop Plug-in (6 and up)
GIMP Plug-in
Paint.NET Plug-in [dead link] – the official website
Paint.NET Plug-in – archive on Wayback Machine
3DSMax plugin (versions 6 to 2009)
Batch Conversion
7.5 to 7.4 Batch Converter

See also