The Mega-Texture Editor lets you view and edit Mega-Texture files for Petroglyph's games.
To run, just unzip the archive to a location of your choice and start MtdEditor.exe.
A Mega-Texture consists of two files: a Mega-Texture Directory (.mtd) file and a Mega-Texture Image (.tga/.dds/etc) file.
To open a Mega-Texture, use the File > Open menu command. The editor will first prompt you for the .mtd file, and then the .tga file.
A Mega-Texture can be thought of as a container for many small images. After opening a Mega-Texture, the editor will list all images.
You can view an image by selecting it. Once selected, you can use the Edit menu to rename, delete or extract it.
To add new images, use the Edit > Insert Files menu command and select the images to add.
Please make sure that, when adding images, the transparency layer is set properly and the background of the image is black.