A rumor surfaced last week that S.T.A.L.K.E.R. was guilty of stealing graphic textures both Doom 3 and Half-Life 2. The story was reported around the internet with some websites, such as theinquirer.net, saying that "stunning similarities" occurred in the water textures of Stalker and the other previously mentioned game titles.
Apparently, the accusations are not only untrue; the so-called stolen textures come from a graphics software pack sold by Marlin Studios — which are supposed to be used in the development of game or graphics software titles.
Valve has chimed in and says that the textures in question were also used by them in developing Half-Life 2. As far as the Doom 3 texture, it was just a standard light texture available for anyone to use.
No harm, no foul.