how to edit graphics

graphic files can be edited..such as recently, some gravel , grass , cars etc have been available for down load....

my question is can someone guide me to the editors that do this...I know gp4master can extract them..next how to edit them ie: the tex files, i know how to do the tga files, with paint pro...what about the rest...

thanks
vito



My Machine,
MB K7VZA, AMD Athlon K7 Thunderbird 1.3g, 512ram, 20g wd hdd
CreAtive Sb Live 5.1, Nv Geforce 3 Ti 128ram with 30.42 drivers,
Windows ME (partioned) KeyBoard racing . frapps..29 to 32 frames

Well, if you know how to edit tga files (and their alpha channel) and you also know how to extract tex files with gp4master, i think you know all you nned to edit files.
The way to do it is the following one:
1 - Extract wad file in a folder with Gp4master Wad workshop
2 - Browse tex files in the just created folder and select the one you want to edit with Tex workshop
3 - Choose extract selected file with tex workshop and save the corresponding tga file somewhere on your hard drive
4 - Edit the TGA file with some editor (PSP, Photoshop...)
5 - Open again your tex file in GP4Master
6 - Choose Replace file in GP4Master's tex workshop and choose the downsample button to make low detail textures (or import them in separate TGAs)
7 - In the wad workshop, choose Make wad from a dir and put the path of the directory where you extract the wad in 1
8 - Found where has been create the wad you just created (in the last folder you open with GP4Master generally) and copy/ write on top of the original wad file in your GP4 dir
9 - Verify you did a good work, trying GP4 again
10 - Have a good day