If you like the Q3 map format, you may be interested in QUALKER 0.3 total conversion that has one of the most complex Q3 maps ever made (there are 2 or 3 large maps, but the first map of the single player campaign to me is particularly remarkable):
Screenshot:
www.quaketastic.co...s/qualker_2.gif
Download (it's standalone, no Q1 or Q3 required):
www.moddb.com/mods...ads/qualker-v03
Mod author: KleskBY
Blender OBJ to Q3 converter used for this, as I understand:
github.com/c-d-a/io_export_qmap
Map compiler:
Netradiant Custom at github.com/Garux/netradiant-custom
Engine:
The map is using Zircon Engine (fork of DarkPlaces retaining full compatibility, although large number of user interface enhancements and some extra capabilities) at www.moddb.com/mods/zircon-engine
This map probably could eventually be made to load in Quake SandBox -- which has a high capacity Q3 engine that is a fork of Open Arena, but due to using q3map2.exe to target the DarkPlaces engine
---
I don't claim this is the most complex Q3 map ever made --- no doubt there are many fine and ambitious Q3 maps out in the wild -- but the complexity of the map and the terrain and the level of detail is quite high and the map was largely made in Blender (KleskBY can do things in Blender that would very difficult or maybe impossible to do in any of the Quake 3 map editors -- he once gave me a video of him working in Blender in real-time modifying an "outdoor pipe line system" in a map and was stunned). In fact, a year ago, QUALKER 0.2 ran using a Github Beta version of DarkPlaces with some stability issues and it was not using the Q3 map format at all, but rather the .OBJ model format (which DarkPlaces has been able to load for years).
Anyway, just sharing information for anyone taking the time to read this thread --- if you take the time to look at the screenshot and the sheer detail and terrain -- it is quite interest what can be done with the Q3 map format with the current toolset / compilers and using a high capacity engine to run the maps.

Hmm, it's interesting and i will test it now

hmm it's not quake 3 format or this use obj and modified q3map2 compiler, i want sources of this map

Hey noire, I didn't notice your reply because in September I was trying to get a mod out (didn't happen) and when I came up with the .map processor idea, I was coding furiously for an extended period.
When I load up the Qualker start map in Zircon (the qualker.exe is Zircon), I type "map":
Output ....

map is lost_village

supportwateralpha? Yes
vis data? Yes
num triangles 422459
num vertices 595090
normalmins -3840.0 -4096.0 -256.0
normalmaxs 5120.0 4352.0 1792.0
size 8960.0 8448.0 2048.0

Keys

mapversion "220"
classname "worldspawn"
tb_textures "textures;textures/common;textures/stalker"
ambient "5"
fog ".3 .3 .25 .2 .6 20 2000 1500 30"
message "Lost Village"
light_lev "25"
q3map2_cmdline "-bsp -meta; -vis; -light -fast"
q3map2_version "2.5.17n-git-5daf2e2"
I'm not as familiar with Quakesandbox engine as Zircon, but I see DarkPlaces fog numbers. Those are incompatible with stock Q3 (99% certain, I remember fog being a crasher when I was trying to get some of my maps loading in your game).
So the "fog" could be a load issue for Quake Sandbox.