Making NPC walk/run/attack/whatever without nodes?

[I'm great]

I've seen some SNPCs that could walk only on noded maps, but as you see, HL2 NPCs such as combines can walk on the map without any nodes, and metrocops can run to player with stunstick without any nodes too.
Is this possible for SNPCs?

[Lenny.]

Use [URL="http://wiki.garrysmod.com/page/User:HighVoltage/Nextbot_Tutorial"]nextbots[/URL], you only need to generate a nav mesh using the concommand "nav_generate" (your game will freeze for some time depending on the size of the map).

[Rubat]

You can make nextbots move without nav_generate by the way - self.loco:Approach(), but it only follows straight lines.