The interface

From top to bottom: menubar, toolbar, the views between two side panels, and the status bar.

Views

Four views: 3D (perspective) top left, and three flat views: top, front and side. Click a view to give it the keyboard; it gets an outline. Drag the lines between views to resize them.

• M maximises the view under focus, and restores the four-way split. The ↗ button in a view's top right corner does the same for that view.
• The name in a view's top right corner says what it shows. Choose another to swap: the view you choose moves to this corner, and this one takes its place. The editor remembers the arrangement.
• The 2D views fill in the rooms cut at one depth. Drag from a ruler with the right mouse button to move the cut of the view across from it. See Camera.
• Each 2D view has rulers along its top and left edge. Click or drag in a ruler to move a working plane: the plane new brushes are drawn on in the other flat views. Or point at a face and press . to put the working plane through it: in a 2D view, that view's plane; in the 3D view, the plane of whichever view the face faces.
• The View dropdown in the 3D view's top left corner holds what that view draws: the visualisation mode, grid, wireframes and overlays. See Keyboard reference.

Menubar

Addons can add their own menus after these. Every item shows its key. See Keyboard reference for the full list.

Toolbar

Left to right:

The terrain, decal, lightmap and sky tools have no button. Use the Tools menu or their keys.

The Cells: dropdown colours the rooms in the 2D views by what a system knows about them. Interior / exterior is built in; addons add their own.

Play runs the selected entities, or every entity when nothing is selected. The editor's background turns red while running and orange while paused. Stop puts everything back.

Side panels

Each side panel is a stack of boxes, each under a dark header with its name. On a small screen, put them where you have room:

• Click a header to fold its box down to the header alone. Click it again to open it.
• Drag a header to move its box. A blue line shows where it will land, in either side panel.
• Right-click a header to fold it, move it up or down, or send it to the other side panel. Reset Panel Layout puts every box back where it started.

Drag the edge of a side panel to resize it. When the boxes are taller than the window, the panel scrolls. The editor remembers the widths, where each box is, and which are folded.

Where the boxes start:

Left panel

• Selection: what is selected, and the narrowing controls. See Selecting.
• The entity, prefab or prop browser, while its tool is active.
• Tool help: the active tool's name, what it expects next, and what each click and key does. Read this when a tool seems stuck.

Right panel, top to bottom:

• Active texture swatch. Click it to open the texture browser.
• Layers. See Layers.
• Problems, only when there are any. See Problems.
• Properties, the inspector, when something with properties is selected. See below.
• Tool options: the active tool's panel, including the audio and navigation tools' panels.

A box with nothing to show, such as Problems when there are none, is hidden along with its header.

Inspector

Shows the properties of what is selected. Change a value to change it on every selected object. Each change is one undo step.

• Entities: an Entity type picker, then the type's properties. A value the selection disagrees on is shown as mixed; setting it sets it on all of them. Hover a property's name for what it does.
• Running entities: a Runtime section with the live values, and a button for each action the entity offers. Actions are not undoable; Stop puts the entity back.
• Air brushes: Fill (what fills the room), and any sections addons declare, such as acoustics. A section appears only when it applies to every selected brush. See Fills.
• Several things selected: a list of them. Hover a row to light it up in the views, click it to select only that one.

Status bar

Left to right:

• Grid size, with − and + buttons.
• The latest message. Hover it to see the log. It flashes red when that message is an error.
• While the map is saving, a spinner and how far the save has got. Saving runs alongside the editor, but nothing can be edited until it is done. Once the map file is written, the first save of a session may compile the map's other variants for their worldrep caches, which on a large level takes a while; Cancel skips that, and they compile when the map is next loaded.

What is selected is shown in the Selection panel.

Right-click menu

With the Select tool active, right-click in a view without dragging for what can be done with what is under the cursor.

• Right-clicking something outside the selection selects it first.
• Right-clicking inside the selection keeps it, so the menu acts on all of it.
• Only what applies is listed. Entities also list their own actions and the Simulate / Pause / Stop and Reset controls for just that entity.

Command launcher

Press / (or Cmd Shift P) for a field that runs any command by name, in any tool. Type a few letters and press Enter to run the top match:

1. Select two brushes.
2. Press / and type me.
3. Merge Brushes is at the top. Press Enter.

• Letters match the start of any word, the initials (mb), or a word the command is known by (join). Every word you type has to match.
• ↑ ↓ choose another row. Esc or Cmd Shift P closes it.
• Each row shows the command's menu and its key, so you can learn the key.
• Commands that cannot run with what is selected are listed last, dimmed. Enter on one does nothing.
• What the selection's entities can be asked to do is listed too, as in the right-click menu.
• Commands you ran lately come first among equal matches.

Every command an addon or your game adds is in it as well.

UI size

View → Bigger UI (Cmd =) and Smaller UI (Cmd -) scale the editor's own interface. The editor remembers it, with panel widths and view toggles, between sessions.