NSBTX Files (NITRO-System Binary Texture) store a set of 3D textures. It follows the [NNS G3D Binary File Format|G3D Binary File Format] with the signature {{{"BTX0"}}}. An NSBTX file must contain only a {{{TEX0}}} block.

!!TEX0 Block

The {{{TEX0}}} block stores the texture data. It takes the following structure:

||Offset||Type||Meaning
| 0x00   | u32 | Texture VRAM key (set at load time)
| 0x04   | u16 | Size of texture data, right-shifted 3 places
| 0x06   | u16 | Offset to the texture dictionary relative to the beginning of this structure.
| 0x08   | u16 | Texture flags. Set to 0 in file, gets set to 1 when loaded.
| 0x0A   | u16 | 
| 0x0C   | u32 | Offset to texture data.
| 0x10   | u32 | Compressed texture VRAM key (set at load time).
| 0x14   | u16 | Size of compressed texel data, shifted right 3 places.
| 0x16   | u16 | Offset to the compressed texture dictionary. Set to 0 if not present.
| 0x18   | u16 | Compressed texture flags. Set to 0 in file, set to 1 when loaded.
| 0x1A   | u16 | 
| 0x1C   | u32 | Offset to compressed texture data.
| 0x20   | u32 | Offset to compressed texture index data.
| 0x24   | u32 | Texture palette VRAM key (set at load time).
| 0x28   | u16 | Size of texture palette data, right-shifted 3 places.
| 0x2A   | u16 | Texture palette flags. Set to {{{0x8000}}} if there exists palettes for {{{palette4}}} textures (since this imposes new position requirements in VRAM).
| 0x2C   | u16 | Offset to texture palette dictionary. Set to 0 if not present.
| 0x2E   | u16 | 
| 0x30   | u32 | Offset to texture palette data.
| 0x34   | ... | Texture dictionary
| ...    | ... | Texture palette dictionary
| ...    | ... | Texture data
| ...    | ... | Compressed texture data
| ...    | ... | Texture index data
| ...    | ... | Texture palette data

!Texture Dictionary

Each entry of the texture dictionary takes the following structure:

||Offset||Type||Meaning
| 0x00   | u32 | Teximage_Param
| 0x04   | u32 | Extra texture parameters. The lowest 11 bits are the texture's source width. The next 11 bits are the texture's source height. These may be smaller than the real texture dimensions. The most significant bit is set when the real dimensions (in the Teximage_Param) match these.

!Texture Palette Dictionary

Each entry of the palette dictionary has an entry of the following structure:

||Offset||Type||Meaning
| 0x00   | u16 | Offset, right-shifted 3 places. 
| 0x00   | u16 | Flags. Least significant bit set marks a palette for a {{{palette4}}} texture.