Earlier ago I made a tool that will come in handy while working with any graphics modding for the game. It enables Photoshop to open and save DDT files directly. With the saving options, you no longer need to work with the numbers inside the bracket after converting a DDT file to TGA with AoE3Ed's FileConverter. Here is showcase of the saving dialog:
Also, this plug-in generates higher quality MIP maps than both AoE3Ed and the original game. This will result in higher resolution textures to look better in-game. There is a controller below to increase/decrease the sharpness of the MIP maps depending on the resolution of your texture, or low/ high poly of the target model.
The plug-in requires Adobe Photoshop CS3 or later, for both x86 and x64 versions. Originally, the plug-in is intended to be used internally, but it's always good to share it with the whole game community. :)
Download Links:
Besides the plug-in, I've been working with Daniel to break the hardcode limitations of Age of Empires III, we've achieved to have more than 14 AIs in game, and revolutionary banners for user-created revolutions. Keep track of our project here:
Feel free to leave any feedbacks or suggestions. :)