So terrain can have automatically placed detail sprites like grass. For this it uses a material called "detailsprites.vmt" linking to a texture called "detailsprites.vtf" in the folder "detail" under "materials". The combinations of sprites that are made from that material and used in maps are specified in "detail.vbsp" in the root folder of the game. Now it's possible to make a custom material/texture and a custom detail.vbsp file. All that should be required to use it after making those is to link to them in "map properties" in Hammer (last image of the first post in the link below). However this doesn't seem to work. It keeps using the standard files even if I tell it to use my files. At last I tested this by copying the standard files, leaving them in the same folders and simply renaming them and correcting their path references to the new names. I inverted the colors of the texture for a visual difference and changed the map properties to link to the new files, but it still used the old ones. If I remove the old ones, it uses none. Info on detail_sprites http://www.interlopers.net/forum/viewtopic.php?f=11&t=33402&hilit=custom+detail+sprite+material Still I remember seeing custom stuff in the past. Yet this should be so simple that I can't see where I could've done something wrong. Bug or me being very, very stupid ? Edit: nvm, it seems to require a pc reboot for some reason. Restarting Hammer alone isn't enough.