Click

Place the piece (or remove, with Remove on)

Drag

Turn the view. Right-drag does the same.

Shift + drag, or middle-drag

Slide the view

Scroll

Zoom

W A S D

Move across the ground

Q / E

Turn the piece one step (22.5°, like the game). R turns it a quarter.

Right-click a piece

Remove it

Middle-click a piece

Build more of that piece

Hold Shift

Place freely, without snapping

[ and ]

Lower or raise the piece by half a metre

G

Half-metre grid on bare ground, on or off

F

Bring the whole build into view

V

Show structural support colours

1 to 8

Pick one of the recently used pieces

Ctrl + Z / Ctrl + Y

Undo, redo

On a touch screen: one finger turns the view, two fingers slide and zoom, a tap places.