I think you need to go through the map yourself to see all the ground types, and then record the coordinates.
are you serious ?
just use processLineOfSight
This is a leaked script
https://forum.multitheftauto.com/viewtopic.php?f=91&t=73462
Don't know about others but personally i would not help you with this script.
iam using Txd Work shop to edit GTA3.img or IMG tool
I didn't ask you how you created your models, I just asked how you are testing your models
Like are you replacing your custom made models using engine functions or you are just replacing your models in your gta3.img