I've been looking at the texture files in a hexeditor and comparing them, noticed some things. Between files of the same size and dxt type theres no change in the header, between files of the same size and different dxt types one byte changes, the 29th. This is 10 for DXT5 and 40 for DXT1. This applies to textures for units. Between textures for units ant those for other types of models, such as those in the attachment sets and new vegetations folder the 17th and 18th and 25th and 26th bytes change values.
My guess is that as the header is only changing between different types of models and dxt formats, it should be safe to strip out the header, edit the dds and reinsert the header and try it ingame. I've made an attempt to do this but I only have the demo and it doesnt seem to use unpacked files so it came to nowt. If anyone else wants to try it the file is here:
http://rapidshare.com/files/7762805/test.rar.html
Unzip into the data folder, it should replace french chivalric or dismounted knights.
I've only noticed one other byte changing between files, the 46th seems to change value depending on the size of the file, although I've noticed two files of different dimensions but same area having the same value. Likewise I've noticed two files of the same dxt type having different values for the 29th byte, 10 and 20. I havent noticed two different dxt formats using the same value though. The other two byte sequences dont seem to have any effect ingame if you change them to those used by another type of model. Other than that I havent noticed any other changes between the headers in different files than those 6 bytes.
