Stacker Tool
How to Use
The Stacker tool lets you quickly duplicate a prop in a straight line, stacking copies along the direction you choose. It's a huge time-saver when building walls, floors, pillars, or anything else that needs lots of identical props lined up neatly.
Hold Q, select the Stacker tool from the list on the right, then aim at the prop you want to copy. Use the tool's options to set the count (how many copies), the direction to stack in, and any offset or rotation you need. Left click the prop to stack the copies.
Because the stacked props line up perfectly, the Stacker tool gives a much cleaner result than placing each prop by hand.