Optimising GTA 2 Maps

GTA 2 file formats are much more detailed than those for Grand Theft Auto 1 and it is very easy for them to grow to enormous sizes. However, there are tools for GTA 2 which use its excellent compression formats to produce sensible file sizes.

Landscapes (.gmp)

These will always be over six megabytes (6MB) if they are not compressed. Delfi has made a tool which works with the GTA 2 Map Editor to reduce these files:

GMP Optimise by Delfi

To use this tool you must open your map in the GTA 2 Map Editor. I normally make a little change (I normally move a light marker one block North then move it one block South) so that the mapper gets a good handle on the file. Then use to the File > Save As Compressed menu to get a Save As type of dialog box. It gives you some options, so I recommend you use these:

‘Save As’ dialog window.

If you select Remove hidden tiles then the editor will remove tiles which it thinks will never be seen or collided with. You can end up losing side texxtures where slopes meet each other which creates graphical glitches when playing the map. However, if you remove the textures from faces which do not actually need a texture and return the rotation of all these faces to zero, you can reduce a lot of file size. Just check all your slopes afterwards!

Texture Archive (.sty)

Raster (pixel) graphics take up a lot of data and in GTA 2 there are a lot of graphics. This is mainly because of all the special variants of the textures. If you have made your own textures, then Delfi has made a tool which allows you to delete pages which you are not using, which reduces file size.

One of the features in the GTA 2 map editor is an option to mark all unused tiles as shown here:

'Mark all unused tiles' option

If you are never going to use these tile textures, write down which ones they are and then delete them from the .sty file. This might not save any filesize unless you rearrange all the remaining tiles and delete any pages which are now empty. Doing this means you have to reset a LOT of textures in your map, which takes a very long time. If you have already made a big map, then doing this would not be a good idea!

What About Other Files?

No other files have GTA 2 compression functions written for them. The mission scripts, which use the .scr extension, are always about 80kB because that is their maximum size. Only the radio stations and special sounds are compressed using special audio filetypes and you cannot do much with these. Normal sounds are just archived in the .raw files and are not actually compressed.