Like Callistonian said, AoMEd is unable to convert DDT files of the Extended Edition because they are in a completely different format. To convert AoM:EE DDT files, you need to use the command line tools located in the Tools sub-folder in the game's folder (usually "C:\Program Files (x86)\Steam\steamapps\common\Age of Mythology\tools".) There are 2 tools TextureCompiler.exe, which converts TGA files into AoM:EE DDT files and TextureExtractor.exe which converts AoM:EE DDT files into TGA files. If you are uncomfortable using the command line, you can use the Texture Conversion Tool interface which Callistonian has linked to.
Here is the thing: AoMEd converts DDT files into Bitmap files (or BMP files if you prefer), Bitmaps don't have an alpha channel (AKA transparency layer), so to represent the transparency/player color, the file is split in two, the upper half is the Diffuse map and the lower half if the alpha map. AoM:EE on the other hand converts DDT files into Truevision TGA files, TGAs support transparency, so the two layers are on top of each other, which is why it doesn't look the same.
To separate the diffuse and transparency map, this is what I do:
- Open the extracted TGA file (just the standard one, ignore Normal, Specular and Gloss,) with
GIMP.
- Right-click on the layer
- Click "Add Layer Mask..."
- Select "Transfer layer's alpha channel" then click "Add"
The diffuse and alpha are now separated, you can select the alpha channel and press delete to reveal the diffuse map in full.
The reason why your select circle looks like that is because TextureExtractor.exe is bugged, for some reason the alpha channel is split into columns and flipped horizontally. In the case of the select circle, the columns are 4 pixels wide, if you flip all the columns manually, you'll see it makes a circle.
Now, saving the textures in TGA format to convert back into AoM:EE DDT format is also tricky, but if you haven't had any trouble with that, then I won't go into it.[This message has been edited by Nick3069 (edited 08-01-2017 @ 06:39 PM).]