I've been working a little bit on a pathfinder building game.
When you press the black box down at the bottom you can place a "Wall" piece anywhere on the layout. Left click the black box, right click anywhere to place the box. These boxes are supposed to be solid.
Press "P" to switch to play mode, when you are in play mode the player will be using Pathfinder to move around. The pathfinding works perfectly except the fact that the character totally ignores the walls he just moves right through them.
Press "B" to get into building mode. In building mode you can also move the player around.