                               OGF Tool                    
                       by Chris Ledwith aka Gwar
          ------------------------------------------------
                                 v0.5

                             README file

OGF Tool is a utility for converting textures in Descent 3 (.OGF 
files) to .TGA and other formats.


Current features include:
- OGF to TGA conversion, with mipmap support
- TGA to OGF conversion, without mipmap support

Features planned for next version:
- mipmap support for TGA to OGF (automatic mipmap generation)
- maybe some more file formats


Note on mipmaps:
Mipmaps are textures stored at a number of different resolutions. In 
Descent 3, each mipmap level is 1/4 the size of the preceding level. 
For example, a 128x128 texture with 5 mipmaps will look like this:

-----------------     ---------     -----     ---     --
|               |     |       |     |   |     | |     --
|               |     |       |     |   |     ---     8x8
|               |     |       |     -----    16x16
|               |     |       |     32x32
|               |     ---------
|               |       64x64
|               |
|               |
-----------------
    128x128

mipmap level 1: 128x128 (the original texture)
mipmap level 2: 64x64 (lower resolution, used by the game for somewhat 
                  a distant object)
mipmap level 3: 32x32 (smaller still, used for a more distant object)
mipmap level 4: 16x16 (for an object even further away)
mipmap level 5: 8x8 (an object on the very edge of vision)

All mipmaps for a given texture are stored in the same .OGF file. When 
converting from the .OGF format to a standard image format 
(like .TGA), OGF Tool gives you the option of saving the extra 
mipmaps, if any exist, to separate files.


Thank you for using OGF Tool.

-Gwar

Email: gwar@descent.org -OR- syrinx1@mindspring.com

URL: http://www.descent.org/descentia/


Thanks to Parallax Software for the Descent series and especially 
Outrage Entertainment for making Descent 3.