I already have a navmesh for this map. I’m not giving it out, but I will give you something better.
I will tell you how to do it so you know.
Here’s a tip: You can’t do most large and intensive maps in Garry’s Mod, just crashes late in the process usually.
Download Source SDK Base 2007 in the tools tab in your game library. (I think it’s 2007, all I know is it’s not the 2013 one), launch the map through the console on the main screen by typing “map mapname” in the console without the quotations after you drag the map into the maps folder under the SDK Base directory. It will auto suggest the map in the console if you put it in the right place.
Then after you load in the map, ignore missing textures, that has no effect on the process. Type nav_quicksave 1 (this command is vital, and turning it on still provides all you need for walk/navigate/kill NPC’s. This will skip the analysis of the generation process, cutting the time taken WAAAAY down, nav meshes will be missing information for advanced AI planning that things like Counter-Strike bots use) in the console, then type nav_generate. It will begin sampling walkable space.
Depending on your processor and the map size, the time will vary. I have an i7-4770 at stock speeds, and rp_apocalypse took me about 5-7 hours. I tried another large map once that nobody knows about, and that took me about 12 hours.
I have navmeshes for rp_stalker, rp_apocalypse, Darkdolina, and a handful of other maps for our server. I’m assuming you’re obviously doing this for Nextbot AI. Works fine for our server and gives the NPC’s basic navigation skills for running, navigating around things, and attacking players.
If you plan on using advanced AI like coding them to climb/jump up walls and whatnot, then I would suggest generating one, and then learning how to manually edit them so the AI can take advantage of points like that.
Another thing, although you said it doesn’t matter, navmeshes usually don’t end up that large, not sure where the 250MB thing came from, unless he was doing the unnecessary full process nav generation. Our rp_apocalypse .nav is about 6.3mb, and it works fine.
Another thing to note, is with nav_mesh auto generation, it basically floods out from player spawn points and fills it in. It does not connect ladders or extremely elevated slopes, so for in rp_apocalypse’s case, the navmesh did not fill the bunker under the gas station, so NPC’s could not go down there. It did however fill just about every other area of the map that mattered.
Once the generation process is done, implying you used SDK 2007, the .nav file will appear in Steam\steamapps\common\Source SDK Base 2007\sourcetest\maps