When I should use DXT1,3 or 5?

[Noif de Bodemloze]

I have working on my better textures mod, but still I wonder during modding that when I know which dxt1,3 or 5 I should use in my texture?

[TuCoT]

For diffuse with alpha channels - DXT1 - 1 bit Alpha
For diffuse without alpha channels, gloss maps and specular maps - DXT1 - No alpha
For normal maps and mask maps - DXT3 - Explicit alpha

And some info about Rome II texture formats:

Diffuse: Main texture file, may include an alpha channel, all RGB channels active
Normal map: This is basically surface map, Blue channel always black, Red channel always white, only Green channel determines normal map. Also it must be include a reverted Green channel as an alpha channel.
Gloss map: Light map. Determines where and how your texture should receives light. Only red and green channels active, blue is off (black). Red means less light, green means more light.
Specular: Similar to gloss map but difference is this one determines reflection color on textures. For example, I have an iron helmet texture and I want it to shine grey, but coloring grey in diffuse isn't enough to do this, so in specular I must recolor helmet same as diffuse but a little bit lighter.
Mask: Generally for tunics, shields and trousers, determines where should faction or unit primary, secondary or tertiary color shown. I think this one uses four main colors: red (255,0,0) green (0,255,0) and yellow (255,255,0) and black (0,0,0).

[Noif de Bodemloze]

Thanks mate! I hope that I can get them work. Do you have a clue about dxt5? What it is for?