As noted in the community Duke3D HRP thread, these assets were shared so others could "generate normal maps".
Locate your autoload or highres directory in your EDuke32 installation. 4182.rar
The file is a legacy asset package used in the Duke Nukem 3D High Resolution Pack (HRP) community, specifically shared by user Hendricks266 on the Duke4.net Forums . It contains source art assets intended for developers to generate high-quality normal maps for the game's 3D environment. Guide to Using 4182.rar Assets As noted in the community Duke3D HRP thread,