I have a floor tile which is basically a square, but isn't quite. I want to add a small strip around the side to be able to paint/texture this strip separately from the floor.
I've used some maths and the location of the other vertices to calculate the width of the strip. I've then manually added extra vertices to the edge of the square floor, and manually connected them to "next edge" and run them straight along the x/y axis until the intersect with the opposite edge, to form a straight line.
Problem: doesn't create a face; without a face, can't select in Texture Painting.
So I took the 4 vertices I'd created and hit F to form a new Face.
Problem: have new face (one edge of the outer strip of my square) directly overlapping the square that was there before.
I'm guessing they haven't auto merged some how?
How do I tidy this up while ensuring I maintain my outer strip?
I have checked for doubles etc.