Difference between revisions of "Choose the right DXTC compression algorithm"
Choose the right DXTC compression algorithm (edit)
Revision as of 09:54, 23 November 2006
, 09:54, 23 November 2006no edit summary
imported>Blade9722 |
imported>Blade9722 |
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=Preface.= | =Preface.= | ||
Altough most of what I'm describing should appear obvious and trivial to those skilled in the arts, I noticed there are some common mistakes which regularly appears also in the work coming from well-experienced texturers. | Altough most of what I'm describing should appear obvious and trivial to those skilled in the arts, I noticed there are some common mistakes which regularly appears also in the work coming from well-experienced texturers, so I think there's need for some clarifications. | ||
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Compression ratio: 4:1. | Compression ratio: 4:1. | ||
This is often described as "RGB texture with interpolated alpha". The application field is the same of DXT3, theoretically this should be chosen if alpha channel is featuring slow gradients. Again, from my personal experience this | This is often described as "RGB texture with interpolated alpha". The application field is the same of DXT3, theoretically this should be chosen if alpha channel is featuring slow gradients. Again, from my personal experience this algorithm is better than DXT3 in most cases, so I recommend using DXT5 when a comparison is not available. | ||
Notice that DXT1 compression ratio is double than DXT3,DXT5, and so it generates half size dds files. | |||
'''The three algorithms are different only for the alpha channel compression, the RGB part is exactly the same for all three'''. So if you don't need alpha blending you should use DXT1, as using DXT3 or DXT5 will only double dds file size without any improvement in visual quality. Instead, I regularly find out in texture replacement lots of DXT5 compressed textures with the default white alpha channel. | |||
'''The most common mistake is this: some modders probably that DXT5 is increasing RGB visual quality, so they systematically use it caring whether alpha channel is used or not''' | |||
=Color map= | =Color map= | ||