Some environment textures have been replaced with higher resolution versions. Texmod required to use this texture pack.
Use winrar or alternative extracting program to extract the file. Extract the file in a convenient folder where you may keep all other texture (tpf) downloads.
Reach your config files - C:\Users\(You)\Documents\WB Games\Batman Arkham City GOTY\BmGame\Config\
Make a back-up copy of any config files you edit.
Press Ctrl+F and search for 'MaxProcBuildingLODColorTextureSize'
Change value to 4096. Change line underneath 'MaxProcBuildingLODLightingTextureSize' value to 1024.
Save the file and set it to 'read-only' properties.
This config edit is required to avoid high resolution texture glitches.
Texture requires 'Texmod' to work. Download Texmod, run the application and select package mode. Select BatmanAC.exe as target application. Go to the smaller folder icon and use it to find the downloaded texture file. Run the game with selected textures. Don't choose any textures that will overlap each other. The bigger the texture size selected, the longer it will take for the game to load. Trying to find a work around on this, but would advise installing the game on your fastest drive.
Note: only a minor amount of textures (mainly exterior) have been replaced. Working on replacing more.