The cop_plus_terrain.rar file you have requested: Call of Pripyat / Mods / CoP PLUS Terrain - 15.91mb is not available. Perhaps try browsing all files for the game S.T.A.L.K.E.R.: Call of Pripyat and upload any files you want to share or are missing. This is the only information we could locate:
This is simply a set of renamed textures for ground and pine tree branches which make the landscape in-game look a bit more "natural"