So something unusual occurred today. I had a great idea! It occurred while manually setting up some Dynamic Light walls. Maybe it's already been discussed before, but I don't remember seeing it. Once you have your map lined up to the grid, temporarily change the Grid Size to 0.1 units. That way you can easily keep straight lines by using shift-click to attach to a nearby grid vertex. But it also grants a good amount of granularity where the lines are. Plus it makes working with curved and irregular walls easier, imo. If you're a Pro member, you can also use Aaron's amazing Walls script. But sometimes a map doesn't work well with that and it's easier to set up the walls manually. In that case, using the technique above might help. PS It's pretty important to have the map lined up to the grid at normal size first. Otherwise when you go back to normal size, your map and dynamic light lines can be offset from the grid.