Working in the CK i am wondering if there is a way to use the tools of the CK to cut a hole, either round or square or irregular..in the mesh....it seems like it might be possible to place a triangle of nodes in an area of solid existing mesh.....and then delete it and have a hole created with the yellow active edge? that would be the easiest way to create openings for new trees and buildings...and would not disturb the mesh as much as moving things manually. Any info on this?

Toggle lines with G, then create 4 points along those lines in the shape of a square, for example. Then I believe you can toggle triangles with T, select the triangles within the boundaries of your square, and delete them. Thus creating a hole in your navmesh.

There isn't a tool that you are speaking of, but try using vertex mode and place vertices along the lines of triangles as Alex pointed out, then once you have created a triangle of points simply select two of the points and hit delete.

Another tip, incase you make a whole that instead of being a neat square with 4 points, is a total mess with like 10 points; if you select two or more points, and hit Q it will combine them all into one point. As far as I can tell which point it combines too is random if you click+drag select, but if you select just one point then hold control to select more, it merges them all into that first point you selected.

Then you can clean up the hole you made so you dont have a bunch of extra triangles.

wow ..wonderful news! if this works it will be a major work around and speed up for editing mesh, what a great possiblity thanks so much guys for the help and info..i will try all of this out,

i did remember seeing that Q command in the tutorial last night as i was reading them all thru.... this is very promising...thanks again!

the key will be to see if the edges of the new hole are the activated yellow that we need for healthy mesh....i do hope so...i really do..