Texture formats overview

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Direct X Texture formats (DXTn) are licensed use of S3 Graphics Ltd S3 Texture Compression (S3TC) technology.

S3TC Format Comparison

S3TC (aka DXTn or DXTC)

DXT4/5 use an interpolated alpha scheme, they generally produce superior results for alpha (transparency) gradients than DXT2/3.
Some consider DXT5 to be the most flexible general purpose compression codec.

FOURCC FS versions Description Alpha premultiplied? Compression ratio Texture Type
DXT1 All ¹ 1-bit Alpha / Opaque N/A 8:1 Simple non-alpha
DXT2 Not supported Explicit alpha Yes 4:1 Sharp alpha
DXT3 All Explicit alpha No 4:1 Sharp alpha
DXT4 Not supported Interpolated alpha Yes 4:1 Gradient alpha
DXT5 FSX only Interpolated alpha No 4:1 Gradient alpha

Notes

  • ¹ DXT1 with an alpha may cause transparency issues in FSX SP2.
  • Mixing DXT1 & DXT3 textures may cause performance problems.
  • For any packages requiring dual FS9 & FSX compatibility, to minimize any transparency issues, recommend using DXT3 type .
  • For conversion utilities, see the Tools section below.

Alpha Types

INSERT explanation of alpha types, or a link to.

  • 1-bit Alpha - placeholder
  • Explicit alpha - placeholder
  • Interpolated alpha - placeholder
  • Simple non-alpha - placeholder
  • Sharp alpha - placeholder
  • Gradient alpha - placeholder

Tools

Tool Description Rating Availability URL
Image Tool Official - All formats manipulation * * * * * SDK SDK Installation (FSX)
DXTBmp 16/24/32 bit and DXT Extended Bitmap Manipulation ²     * * * Freeware Click button at foot of page (SizeMb)
Tool Name Descriptive blurb ????? Payware Download Page (SizeMb)
ColorPix Colour grabbing tool. * * * * * Freeware Download Page (SizeMb)
  • ² DXTBmp - Not suitable for generating FSX DDS textures, (incompatible type output).
  • ColorPix - Useful for colour-matching when correcting overlaid transparency issues.

Related

Internal

External

  • Direct3D - Exposes the advanced graphics capabilities of 3D graphics hardware, including z-buffering, anti-aliasing, alpha blending, mipmapping, atmospheric effects, and perspective-correct texture mapping.
  • Bump Mapping - A technique to add details to shading without using more polygons.
  • Normal Mapping - An enhancement of bump mapping.
  • DirectDraw Surface (aka .dds) - A file format used for storing textures and cubic environment maps, both compressed and uncompressed.
  • 3Dc - A lossy data compression algorithm for normal maps invented and first implemented by ATI. It builds upon the earlier DXT5 algorithm and is an open standard. 3Dc is now implemented by both ATI and NVIDIA.