Then use HLExtract.exe found in the bin directory to extract the necessary files from the .gcf file found in your steam/steamapps/[email protected]/ directory usage is something like:
HLExtract.exe -p "G:\Steam\SteamApps\source materials.gcf" -d g:\Half-life2-dcom\ -e root\
A lot of people use GCFScape but I think d/ling a 30 meg runtime library is well lazy programming on their part but then who wants to spend days programming for a simple app like this.
Textures for source come with .vmt and .vtf extensions, in the current SDK there is no tool to convert these .vtf to another format (vmt files are just text files you can ignore them for now well I do anyway), there is a program that can convert .vtf files into tga image files its called vtf2tga.exe and was one of the tools that came with the leaked version of HL2 I believe.
Once I’ve modified my texture I pop it in the steam/SteamApps/[email protected]/sourcesdk/cstrike_sample_content/materialsrc/sample1
Open a DOS prompt set VPROJECT=steam/……etc……./ cstrike_sample_content
Then use vtex.exe to convert it back to a vtf.
Then pop the vtf file in the same directory as it appeared in the gcf file but in the correct game directory for example if you were editing alyx texture from HL2 you would put it in:
/Steam/SteamApps/[email protected]/half-life 2/hl2/materials/Models/Alyx
This is the way im doing it Im only messing about so it probably isnt the right way.