Editor Overview
What is the Mars Editor?
The Mars Editor is a mesh-based level editor that's based on traditional level design principles, but with modern tools and conveniences. It is inspired by editors such as Valve's Hammer 5 (Source 2) and modelling software such as Blender.
The Mars Editor is built directly into the game engine, and can be accessed through the Editor option on the main menu, or by launching it via the console command "editor". You can load a map with the editor at the same time by adding the map name after the command, i.e. "editor my_level".
Overview
Toolbar
The top toolbar is where most common tools are located.
The first five icons are Manipulators, used for most common editing tasks. Select, Move, Rotate, Scale and Texture.
The next two are drop-downs for creating Geo and Entities (Objects).
Finally, the rest are toggles for Grid Space, Pivots, Snaps, Texture Locks and the Difficulty Filter. They are all covered in detail below under The Toolbar. This panel cannot be toggled.
Viewports
The main viewport is where you'll do the majority of your editing. By default it uses 4 viewports: Front, Right, Top and Perspective (or 3D). The currently active viewport will be highlighted with a yellow border.
Dragging the edges of a view pane will allow you to resize them, and Enter will maximise the current view pane.
You can swap a viewport with the Numpad 1 (front), Numpad 3 (right), Numpad 7 (top) and Numpad 9 (perspective/3D) hotkeys.
Holding Right-Click allows you to pan each viewport with the mouse.
Holding Right-Click or Shift and pressing W / A / S / D will also quickly pan the viewports.
You can use F to focus the viewport on the current selection.
F2 Toggle wireframe in any viewport, while F3 toggles textures, and F4 toggle lightmaps in the 3D viewport.
Outliner Panel
The Outliner Panel is where all the objects within a map are listed. It is the panel on the left of the editor screen. Objects in Mars Engine use a Scene Tree format, where objects exist in a hierarchy and can be grouped together, or nested (parented) to one another.
This is covered in more detail below under The Scene Tree.
Can be toggled with the O hotkey.
Inspector Panel
The Inspector Panel is where information and options relevant to an object are listed. It is the panel on the right of the editor screen. It populates with contextual information that depends on what object is currently selected, and is where all object scripting and Geo sculpting options will be located.
See Geo Editing and Geo Components for more information relevant to selected objects.
Can be toggled with the I hotkey.
Browser Panel
The Browser Panel is where you can browse all the defined objects and assets within Mars Editor. Textures, props and enemies can be dragged from the browser directly into the scene via any of the viewports. It is located on the bottom of the editor view.
Here you can also register new assets such textures, props and sounds. See Adding Custom Assets.
Can be toggled with the B hotkey.
The Toolbar
Manipulators
Select
The basic selection tool. Allows you to select any element in the world by clicking it in any of the viewports. Properties related to the object will then be shown in the Inspector Panel.
Can be activated with the Q hotkey.
Move
Moves the selected object. You can drag an object along a fixed axis or freely across the axis plane by dragging either the arrow, or the rectangular plane gizmos.
When in a Subobject Mode it will move the selected vertices, edges or faces instead.
Can be activated with the W hotkey.
Rotate
Rotates the selected object around its Pivot. You can rotate around each of the three axis' by grabbing their respective gizmo.
Holding the Z hotkey will allow you to drag a custom pivot point in any of the viewports to rotate around instead. The custom pivot will be lost when switching out of the Rotate manipulator.
When in a Subobject Mode it will rotate the selected vertices, edges or faces relative to each other instead.
Can be activated with the E hotkey.
Scale
Scale your selected object. Select any of the scale gizmos to stretch a Geo in that direction.
Holding Alt will proportionally scale it in all directions, while holding Control will proportionally scale it on the one axis.
When in a Subobject Mode it will scale the selected vertices, edges or faces relative to each other instead.
When non-scalable objects such as entities are selected, scaling will instead space the objects relative to the scale gizmo.
Can also be activated with the R hotkey.
Texture
Activates the global texture manipulator, allowing you to modify the texture placement of all Geo within in the level. Not to be confused with the local texture Subobject Mode.
This is a fairly complex texture tool with a lot of options covered in more detail in the Texturing Your Level page.
Can also be activated with the T hotkey.
Creation Tools
Create Geo
A drop-down for creating Geo shapes, covered in much more detail in the Geo Editing page.
Create Entity
A drop-down for creating game entities.
Toggles
Transform Space
Pivot Mode
Toggles between using the center (origin) of a Geo, or its user-set pivot. The pivot can be manually changed with the Edit Pivot button on the Inspector Panel. This is the point transformations to a Geo will occur around, for instance when using the Rotate Manipulator, or an Animatable Component.
Grid Snap
Toggles grid snapping. Clicking the arrow brings up more advanced settings. You can toggle between grid and vertex snapping, using metric or map units, as well the grid size and opacity.
The [ and ] hotkeys will scale the grid by powers-of-two (e.g. 8, 16, 32 etc.).
The Alt + [ and ] hotkeys will lower and raise the grid opacity.
Holding X will temporarily disable grid snapping, if it currently toggled.
Holding V will temporarily enable vertex snapping, if it is not already toggled.
Angle Snap
Toggles angle snapping while rotating. Clicking the arrow allows you set the snap amount.
The Control + [ and ] hotkeys will lower and raise the snapping by a value of 5 degrees.
Texture Lock
Toggles texture lock, preserving the alignment of textures when objects are moved and rotated.
Texture Scale Lock
Toggles texture scale lock, preserving the alignment of textures when objects are scaled.
Vertex Auto Merge
Toggle vertex auto-merging when objects are transformed. With this enabled overlapping vertices will be automatically welded whenever you move, rotate or scale a Geo. It allows for very rapid and tidy Geo sculpting, but is not always preferable.
Difficulty Filter
Toggles the difficulty filter. Clicking the arrow brings up options to filter out Easy, Normal and Hard entities. Setting the Difficulty Flags on entities will stop them showing up in the chosen difficulties. This can be done to all entity objects, not just enemies.
The Scene Tree
Nesting (Parents and Children)
As objects in Mars Engine are hierarchical, they can be nested together. Any object nested below another is a child, with the object at the top being the parent. Nesting can stack, so objects can be a child and a parent at the same.
The real power of this system is that children will respect the transformations of their parent, so for instance any object that is the child of a moving platform will move along with it. This can stack in extremely powerful ways, even respecting the enabling or disabling of parents, allowing you to toggle and swap out whole chunks of a level, including all the props, effects and monsters within!
The potentials of this system are covered more in the Geo Components page.
Groups
Objects can be grouped together to help organise and de-clutter the Scene Tree as they can be collapsed, hiding large amounts of objects from the list. Groups are purely organisational and have no local transforms, so objects within a group will not influence each other (unless they themselves are nested).
Objects are grouped together by selecting multiple objects within a viewport or the Outliner Panel and clicking Edit > Group Selected from the Menu Bar. Alternatively you can use Control + G to group objects, or Alt + G to ungroup them. You can also drag objects into existing groups within the Outliner Panel.