This is a pack with the very basic assets for Indie game projects using the GPL Doom 3 (2004) engine (or any port). All inside pak_cc0stradex.pk4 and pak_cc0Snehk.pk4 is licensed as CC0 (public domain) so you can use it for whatever you want (commercial and non-commercial projects). But all inside doom3_data.pk4 is part of the Doom 3 assets and you cannot use it (the idea of this project is to come with a version without any Doom 3 asset, but by now still there're some little very basic Doom 3 assets.)
Just put pak_cc0stradex.pk4, pak_cc0Snehk.pk4 and doom3_data.pk4 inside your base folder (without any other .pk4 in the folder) and that's it.
All CC0 (public domain) assets this pack include (8.4mb):
Doom 3 stuff that isn't CC0: