I've got a fairly rough surface that i'd like to try projecting decals on. I understand I'm supposed to make a _decal entity out of a patch mesh, cover it in the texture, and target it toward an info_null on the other side of my wall. So far so good...
Only I can't create the _decal entity directly. If I create a patch mesh, it comes out as a worldspawn object. If I select it (and only it) and bring up the key/value pair list and change "classname" to "_decal", it changes the classname of EVERY worldspawn entity (all my walls and brushes!). This is very annoying!
Since it's a rough surface, just creating a patch mesh near the wall is problematic. Any good ideas? What horribly obvious fact am I missing?