Difference between revisions of "Choose the right DXTC compression algorithm"
Choose the right DXTC compression algorithm (edit)
Revision as of 16:20, 3 December 2006
, 16:20, 3 December 2006no edit summary
imported>Deathbane27 |
imported>Blade9722 |
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The DXT1A is often described as "RGB texture with one-bit-depth alpha". Actually, for each pixel there are two available configurations: | The DXT1A is often described as "RGB texture with one-bit-depth alpha". Actually, for each pixel there are two available configurations: | ||
if the alpha channel is set to 1 (white), RGB channels store usual color info | if the alpha channel is set to 1 (white), RGB channels store usual color info. Instead if the alpha channel is set to 0 (black), upon saving the texture RGB channel are set to 0 as well. In other words, each pixel could contain color info only if the alpha channel is set to white. | ||
if the alpha channel is set to 0 (black), upon saving the texture RGB channel are set to 0 as well. In other words, each pixel could contain color info only if the alpha channel is set to white. | |||
This makes a sense, as a black alpha channel usually means that the pixel is completely transparent (invisible), so there's no need to store color info. | This makes a sense, as a black alpha channel usually means that the pixel is completely transparent (invisible), so there's no need to store color info. | ||
This algorithm is tipically used for icons, decals, blood, tatoos, i.e. texture with a completely transparent part. | This algorithm is tipically used for icons, decals, blood, tatoos, i.e. texture with a completely transparent part. | ||