Advanced Settings

Example level

You can see all Selection Manager features and usage examples in the example level,
located in the plugin's Content folder.

Marquee Collision

If you do not provide custom settings when registering an object, Simple Collision will be used for selection box detection by default.

Simple Collision uses a single point at the center of the object. If this point is inside the selection box, the object will be selected. This is the most performant option, especially when you have many units.

You can create more complex selection collisions in the settings if you need more accurate selection. See the example level for a working setup.

For cursor selection, the plugin uses the object's own collision. Make sure the object's collision blocks the same trace channel that is set in the Selection Manager settings. By default, this is the Visibility channel.

Mode	Setting	Use it for
Simple	Use Simple Collision (+ Simple Collision Offset)	A single point at the object center. Fastest — best for large unit counts. Used automatically when no LODs are set.
Sphere LODs	Collision LODs	One or more spheres (Center Offset + Radius) per LOD. LODs switch by camera distance (Switching Distance LOD). Precise selection for varied shapes.
Dynamic	Use Dynamic Collisions	Collision returned every frame by Get Object Dynamic Collisions. For collision tied to moving parts or bones. Slowest.

Tuning collision visually

Assign BP_SM_Debugger to the manager's Debugger Class and enable Show Debug Collisions to see the spheres in play. The debugger also has an editor preview mode for authoring collision shapes and copy-pasting them into an object's Collision LODs.

Collision Settings

For more details, see: Collision Settings

Per-object options

Other fields in the Register Object Settings:

Setting	Description
Can Be Selected With Marquee	Allow / disallow selection by the selection box.
Can Be Selected Via Select All	Include the object in Select All.
Can Be Selected By Index	Allow selection by Select Objects By Index.
Selection Index	The object's index for index-based selection.
Selection Formation ID	Group id for "select together" cohesion (see below). -1 = ungrouped.

Selection Manager settings

Cursor

Setting	Description
Trace Channel	Collision channel used for cursor hits.
Trace Complex	Use per-poly mesh for cursor hits instead of simple collision.
Highlight Object Under Cursor	Auto-highlight the hovered object.
Actor Hit Priority	When both an actor and a component are hit, prefer the actor.
Minimum Drag Distance	Pixels the cursor must move before a click becomes a marquee drag.
Disable Cursor Interaction	Turn off cursor selection entirely (marquee only).

Marquee Tool

Setting	Description
Marquee Widget Class	The selection-frame widget. Defaults to WB_SM_MarqueeTool; assign your own to restyle it.
Enable Dynamic Object Highlighting	Highlight objects inside the frame live while dragging.
Snap Marquee Start Position	Anchor the frame's start to the clicked world point, so you can keep selecting while the camera moves.
Player Viewport Relative	For player-attached widgets in split screen.

Widget

You can swap the marquee widget during gameplay with Set Marquee Widget Class.

General

Setting	Description
Orthographic Projection	Enable when your camera is orthographic.
Prevent Reselection Flicker	Keeps the current selection on screen until a new selection is finalized, so it doesn't blink empty for a frame when you start selecting again.
Player Controller Index	Which player controller to use.

Selection Typse

The plugin supports three independent object grouping systems:

• Formation — if one unit is selected or highlighted, all units with the same Formation ID are also selected or highlighted.
• Selection Group — RTS-style control groups. You can bind selected units or buildings to a hotkey using Ctrl + 1...9, and then select that group by pressing the number key.
• By Index — fast selection of units or buildings of the same type,
  for example when double-clicking a unit or building.

Formation selection

When Select Entire Formation is enabled, hovering over or box-selecting any unit will highlight or select all units with the same Formation ID.

A Formation ID value of -1 means that the unit is not part of any formation.

Selection Manager functions for working with formations:

Name	Description
Select Entire Formation	Master toggle. When on, clicking / hovering / marqueeing any member selects the whole formation.
Selection Formation ID	The object's initial formation at registration. -1 = ungrouped.
Set Object Selection Formation	Push a new formation at runtime (unit joins / leaves). -1 to clear.
Get Object Selection Formation	Returns the object's current formation id, or -1 if ungrouped or not registered.
Get Object Formation Info	The object reports whether it's in a formation and which one. Read at registration and on refresh — not every frame.
Refresh Object Formation	Re-pull one object's formation from its Get Object Formation Info.
Refresh All Formations	Re-pull formations for all registered objects at once.
Get Selected Formation Indexes	Returns the distinct formation IDs currently selected.

Finish Selection also returns Selected Formation Indexes in its result (filled only when Select Entire Formation is enabled).

You also need to implement the Get Object Formation Info interface function by creating two variables.

You can use these variables for your own gameplay logic. If you change their values at runtime, call the appropriate Refresh function in the Selection Manager to apply the changes.

Selection Groups

You can create RTS-style control groups by pressing Ctrl + Number to assign the current selection to a group, and then pressing that number to select the group.
You can also set up double-click selection, allowing the player to select all units or buildings of the same type.

Name	Description
Make Selection Group	Save the current selection under a number.
Select Group	Recall a previously saved group by its number.

Selection by Index

Select every object of the same kind at once — for example, double-click one unit to select all units of that type.
When you register an object, set in its Settings:

• Selection Index — a category ID, give the same index to everything you want selected together (infantry = 1, cavalry = 2).
• Can Be Selected By Index — keep enabled, objects with it off are skipped.

Tip

The index is assigned at registration. To change it later, use Set Object Selection Index function

Call one of these on the Selection Manager:

Function	Use
Select Objects By Index	Select all registered objects with that index.
Select Objects By Same Index	Select everything sharing the given object's index - pass the clicked unit (great for double-click).
Select Objects By Indexes	Select several categories at once.

Each has a Selection Only On Screen parameter: when on, only objects currently visible on screen are selected.

Double-click selection by index

When Prevent Reselection Flicker is enabled in Selection Manager settings, a double-click must call Interrupt Selection before Select Objects By Same Index.

Optimization

For large numbers of selectable objects:

Setting	Description
Throttle Marquee Highlight + Marquee Highlight Update Interval	Update live marquee highlighting on an interval instead of every frame.
Use Spatial Grid (experimental)	Broad-phase grid for simple-collision marquee tests. Tune with Cell Size, Selection Plane Z, Bounds Padding, Rebuild Interval.

Debugging

The Selection Manager Component includes a debug mode that displays the collision data used for marquee selection.

Setting	Description
Show Debug Collisions + Debugger Class	Draw each object's selection collision / LODs in play.
Show Debug Spatial Grid + Debug Spatial Grid Draw Time	Draw occupied spatial-grid cells.

Debugger Class

Select BP_SM_Debugger as the debugger class. BP_SM_Debugger is included with the plugin.
You can adjust the visual style of the displayed collision volumes in the BP_SM_Debugger settings.

Modifying plugin assets

If you want to modify any plugin asset, make a copy of it and move the copy to your project folder.
Otherwise, your changes may be lost when the plugin is updated.