Build Gun

The Build Gun is a tool engineers can use to place and dismantle buildings. It projects a hologram showing where the build-able structure will be placed, and highlighting key features such as belt inputs, outputs, and power sockets. It is also the same tool that does resource scanning. The engineer will equip the tool before exiting the drop-pod. The tool is not craft-able and will still be equipped even after the engineer respawns or dies.

Build menu
The build menu is unlocked after the engineer has hand-mined the Iron Ore for the first time.

The build menu is opened with the key by default. Here all the buildings the engineer has unlocked are sorted into tabs. Left-clicking a building will exit the menu and display a hologram version of the building. The engineer can then position it where they want and then left-click again to build.

Buildings can also be added to the To Do List from the build menu.

Snap to Guide Line
Thick turquoise line will be drawn if two buildings are aligned together.
 * While in build mode, press to align the hologram to building Guide Line. Snapping while aiming at the side surface of an existing building will align them side by side.
 * There are a few placement issue with this function though, such as unable to place upper-floor buildings such as fake 'Encroachment' issue or due to terrain features. In these cases, try rebuild without using the snap to guideline feature.

Pipeline pumps
Currently there is a glitch where a building hologram hovered around an existing Pipeline Pump will create annoying snap lines from various angles, even if not aligned orthogonally with the said Pipeline Pump.

Multiple-click building
Buildings such as Conveyor Poles or Pipeline Support need multiple clicks to complete the building. The first click will place it on the ground, then use mouse to adjust the pole's height. The 2nd click confirms the build. You can toggle this setting in the "Options" menu so that you don't have to click 2 times. (Click-drag-release).

Build mode
You can change build mode while building Pipelines and Hyper Tubes. Press while building them will cycle through one of the 4 modes: Default, Conveyor 2D, Vertical and Noodles. Changing build mode can solves some 'encroachment' or 'invalid shape' warning.

Dismantle mode
The Build Gun can be brought out in dismantle mode by pressing the key by default. Buildings that the player's cursor is over will be highlighted, and can then be dismantled by holding down left-click for 1 second. A blinking red border will appear around the screen to indicate that dismantle mode is active. Highlighted building in this mode will show you its name and refund cost. Dismantle a building give full refund.

Holding down while dismantle will enable mass-dismantle, up to 50 buildings at once. All buildings pointed by the mouse will be added to the dismantle list. You can release and then hold down the Ctrl key to 'skip' buildings.

Invalid dismantle targets

 * Deployed place-able equipment, such as Portable Miner, Statues, Beacons
 * Integrated building's attachment, such as HUB's Biomass Burner, Train Station's Integrated Platform Track, Railroad Switch Control
 * Crates
 * Crash Sites
 * Moving Trains
 * All non-buildings

Building query
By using the dismantle gun and aim at a building, you can query a building's input and output cargo items to know what is contained in the building. As the gun has a range of 100 meters, you can perform the query without moving near to the building and interact with it. This can be applied to multiple buildings by using the mass dismantling mode.
 * If the factory is producing item (and consuming input), its contained item counts will not be updated until you re-hover the build gun over the target. Take note when performing a speedrun.

Copy Building
While in build mode or dismantle mode, clicking mouse middle button then aim at a building to copy its hologram.
 * This only copy the building's hologram, its settings such as clock speed or current crafting recipe will not be copied.

Technical details
Placement and dismantle range is 100 meters (12.5 foundation lengths). Buildings can be rotated with by default, in increments of 10°, or 90° when placed on foundations.

Mass building
There are currently no systems in the game equivalent to blueprints (from Factorio) allowing for building multiple structures together. A blueprint system may be added post alpha.

Numeric Hot Keys
The numeric hotkeys have some initial defaults, but it can be customized at any time.

To add a building to a hotkey, open the build menu, hover over the desired building then press a number key. The building is then mapped into that number.

Using to cycle through different Hotbars.

Underwater building

 * While staying above water, buildings can be build underwater.
 * While swimming, the build menu is disabled.
 * While climbing on an underwater ladder, such as Stackable Conveyor Pole built up from the sea bed, you can use the build menu again.

Emote
Pressing the emote wheel and select 'twirl it' will display an animation showing engineer twirling the Build Gun.

Vehicle
Build mode is disabled while riding a vehicle or Hyper Tube. You cannot build while swimming as well.

Construction animation
During construction of a building, an animation displays, where building transition from hologram to solid building from bottom to top. For logistic buildings such as belt, it is according to the direction of built. Ingredients appear fly from the engineer to the building, but as soon as the building is placed down, it is function-able. For example, foundations have a build animation of about 1.5 seconds, but you can stand on it once it is built, no need to wait for its built animation.

Trivia

 * When exiting the drop pod at the start of the game, the engineer fastens a partly loose sticker on the Build Gun/Resource Scanner. The sticker is a picture of Box Boy from Coffee Stain Studios' very first game, I Love Strawberries, released in 2010.
 * The Build Gun has numerous lines of text printed on its casing.
 * SN: 0987654321
 * RU1F-M40
 * 41PH4-BUILD 1.0
 * 54L-T