When you don't care about the exact position and orientation and species of each tree on your layout, but you want to fill in an area with trees to designate that you plan to put trees (or other vegetation) in that area, adding trees one at a time to the layout can be a pain and take a lot of time.

It would be fun to add a feature where a user can specify a rectangle that they want filled with random trees. Then BrickLayouts would randomly select trees to fill up that space. The user would be able to specify how "packed" the trees should be as well, since maybe they want some open space between trees, or they want them overlapping with each other a whole bunch. The added trees should be automatically grouped so they can be easily positioned.