I have a page set up with everything you need to know about KMQuake2 editing here: www.markshan.com/knightmare/editing.htm It's Radiant-centric, but the same surface flags shown in QERadiant should also be present in the Quake2-supporting TrenchBoom 2.
You should avoid using Quark for KMQuake2 mapping. Quark allows the making of maps with inefficient brush structure, which end up hitting the numerical limits of Q2's BSP format much sooner, around 2000 brushes, whereas with other editors you can easily go over 6000 brushes without hitting those limits.
I added the def file thats needed for gtkradiant in order to map for kmquake2,but when i open gtk it asks me what game do i wish to map for?Should i select quake2?Or should kmquake2 appear in the list of games to map for?Do the props and objects by any chance support any other format other than .md2?Can i use .ase or .obj or something like that?
Maybe i should explain this better,ehm.Im not exactly trying to map for q2 iam just using kmquake2 and putting in my PAK files,my own maps,my own AI,my own models,and my own textures.Iam making a game with kmquake2.Thats the thing.In what exact gtkradiant folder should i put the lazarus def?And do i need the kmq2bsp in order to compile the map i have made?
also another issue that iam facing is the missing cursors and stuff,i have ported vanilla q2 to kmquake2 just to test and i have noticed a lot of stuff being missing,for example guns bullets are in wireframe and it constantly says missing cursor.pcx or missing gfx/ui/cursor and stuff like that,what do i do?
The missing images are stuff that's in kmquake2.pk3. You need the contents of that pk3 in your game's files for KMQ2 to work properly.
The lazarus.def file's location needs to be specified in the "entitypath" key of the project settings (.proj file) you're using in GTKRaddiant, assuming the latest version of GTK Radiant still works like the previous ones. There shouldn't be a specific folder where it has to be.
You should probably contact TTimo or whoever else is in charge of GTKRadiant for advice on configuring it for your own stand-alone Q2 engine-based game. I've mostly used the old QERadiant 147 for Q2 mapping.
You should definitely use kmqbsp3 instead of regular qbsp3, as it's optimized for KMQ2. It's not exactly required, but will be a great help.