External Tools for Textures: Overview

All textures used by the Editor are also divided into smaller ones according to conventional map pieces and stored withtin the data\0_0 ... data\3_3 folders corresponding to these map pieces.

You can find them there as a set of .tga (or .dds) files.

As before, you can modify them not only by means of the Editor, but also in third-party tools that support .tga or .dds formats.

However, for some textures, you will probably want to modify the full-sized texture corresponding to the whole map and then divide it to map pieces.

That's what the Combine chunks in directory and Separate chunks from directory context menu commands are for.