Biomes would be nice to see, like Swamplands, Mountains, and Flatlands. All presets of course.

Not a suggestion but rather a question, would it be possible to get AI/npcs/snpcs to interpret the terrain? They can already sort of walk on it, but they can't quite understand it. I know source engines AI system can be VERY limiting due to nav meshes and ai nodes being baked into a map. But I just wonder if it would be possible? I'm assuming not since I doubt it would be possible to efficiently create a navmesh for this mod, since I don't even know how the hell that would work. THAT would be truly pushing the source engine to it's absolute limit. Anyways, if Mee sees this, i'd like to say. Your work continues to astound me and obviously the rest of the gmod modding community. Thank you for the black magic you have crafted.

Also, i'm a dumbss I just remembered that navmeshes aren't "baked" into a map they ARE technically a separate file. So... maybe it could work? Very unlikely, and that would be it's own black magic.

it would be nice if you could change what models were used for the rocks and trees if possible (though this might not be possible judging by how jank and complex the tree system already is based on what i heard)

ai is cursed, if there was an easy way to do it i would but i honestly dont know, can you even generate a navmesh on the fly?

as for trees, i am slowly rewriting the tree code to easily support different models, so that may come up eventually
(though youre right, the tree code is jank and complex)

A way to use an external heightmap texture would be interesting, not sure how feasible that would be though.

Something that would more interesting is a way to "paint" the terrain similar to a heightmap, like some terrain editors, although that is much more unlikely and harder I suppose.

Well technically you generate nav meshes IN game, but the server/map itself completely restarts for them to even take effect. So i'm not sure. It just seems there might be a way for npcs to walk on the surfaces consistently. I don't think it would ever be perfect but at the very least they can walk straight up a hill chasing you the player or going for some objective. One thing I know for a fact is NPC tool's "NPC path" can make npcs climb hills. So I think the only reasonable way to make npc's traverse the terrain is by overriding their comprehension of the terrain (similar to npc tools forcing them to walk from point a - b). My best theory is telling their A.I to ignore the terrain all together. I.E pretend it doesn't exist. But still have collisions with it. The issue is they THINK theres a wall in front of them when really it's fine to keep walking forward. I have no ♥♥♥♥♥♥♥ clue if that's possible but it's a theory. OR making some system to simulate a fake nav mesh ontop of the already working navmesh? But that ♥♥♥♥ would be insane so I have no clue. Idk if your interested in NPCs, those are my theories but I'd have no idea how realistically accomplish able anything is.

Perhaps add a feature to set the terrain physical properties. If one were to do sled build, they could have the entire world super-iced!

would be better, if skybox changed too. Sucks when there is mountains and trees that get cut by super flat terrain.

There should be something that spawns on the sky box or something, because the map just ends abruptly. Maybe have some generation at the skybox maybe?

now i know that i havent even tested addon, but i have a question
can you spawn buildings and props from other addons with editor?
and if not, could you add this ability?

Some way to continue the generation to the skybox? if even possible lol

Well I think it is possible, but you know how Stormfox and things like that change the skybox? It is doing it consistently but it still takes a toll on the source engine. Making it go into the skybox would be challenging and could have some impact of performance (even though it is static), but it would probably be worth a shot.

No idea if this is a small request or not, but if you ever port this to another map, could I suggest the gm_black maps or something similar? It has no lighting, but this means it could be possible to make prop lighting match up with the lighting of the terrain with a lamp entity - at the moment on flatgrass, it can look a little like fullbright. Also, and this one I know would definitely be a big ask, but perhaps a way to change lighting in some way through the menu (eg. sun angle + brightness)
Anyway even as it is right now it's still probably the best addon on the workshop - well done!