This is my map ... it has no ground and no sky because I won't be doing those any more.

I get this for free ... (automatically generated) ... the ground is automatically constructed from an initial rect the size of the map bounding box. Each entity (the lake is a func_group, the hill is a func_group) clips away from the initial rect creating more smaller rects <=== that is your ground. Then it takes everything and slams a skybox around it.

And with this compiler directive for the grass ...
"q3map_surfaceModelCollide models/outdoors/variousveg/tree_autosprite2_16_16_32.ase maps/_collide_2_2_32.ase 38 0.00625 8 16 1 122 1"
I get this ...

Edited 1.4 minutes after the original posting.

So many great options with these tools. This is a great example of how you can quickly prototype an idea.

Maybe coming out this month and will have Quake 1 monsters filling it.
Those mountains up top, them ain't skybox. One has a visible radar tower on it.
Edited 1.48 minutes after the original posting.

Wow. Surely one day we will go from .PNG to .map thanks to Gen-AI. Then I can finish the map of my high-school that I started more than 20 years ago and never finished :/

Makes me think of Serious Sam :)

Heh, .png to .map ... I coded 80% of that 2 weeks ago. I lost interest after deciding I wanted a maze generator and started coding that instead. Screenshot from June 12 ... I type "mazegen" in the console and the engine outputs a .map and then I run q3map2 ...

@Tig ..
I had to make about 20 different tools to get that mountain map so far. I used Terrain Generator, had to make a tool to convert upwards facing brushes from common/caulk to a regular texture. I then wrote a tool to detect transtitions from flat to non-flat surfaces and non-flat to flat surfaces and change the texturename (this edge detection changes the texture to have _trim in the name). I also have a "weld" tool that merges adjacent same texture triangles (within each func_group) into rects and then also find adjacent rects and merges them (triangle reduction).
Then the _trim shader had q3map_surfacemodel to plant vegetation.
Believe it or not, the entire map has 60,000 triangles due to q3map2's incredible optimizations (like discarding caulk triangles).
Edited 45 seconds after the original posting.
Edited 1.13 minutes after the original posting.