mmo – Extracting walkable coordinates from 3d scene

is there away to extract the walkable coordinates from 3d scene , so I can have server side validation ? or how would I achieve that with Godot?

EDIt (clarification):

I was just wondering how they are validating the movement from the server side , let’s say Fortnite,pubg or any MMORPG game , how they make sure that the player move from this position to this position? , what came in my mind was , if I can get the walkable points/coordinates save them to file , and on the server side , when a player wants to move from this point to this point , I check my map file , if this point is walkable then allow it , idk if there is any other way to do it.