Placeables

This section documents the actors you place in a scene. Their settings live on the selected object, separate from the shared controls in Interface. Reusable Blueprint lighting and its components are covered in Prefabs.

Objects in Place Actors

Open Unreal's Place Actors panel and choose Spectral, or search for the actor by name.

Actor	Purpose
Spectral Probe Volume	A bounded grid of baked lighting samples for objects, fog, and other probe consumers
Spectral Box Capture	A box reflection capture with Spectral's face-resize handles
Spectral Fog Volume	A local region of fog with density, scattering, and distance controls

Editing box bounds

Select the actor or supported volume component to reveal its face handles. Drag a green handle to resize one side. The active handle turns yellow.

• Normal drag moves the grabbed face while the opposite face stays fixed. The box center moves.
• Hold Ctrl to resize symmetrically. Both sides change and the center stays fixed.
• You can press or release Ctrl during a drag without changing the current size abruptly.
• With editor grid snapping enabled, the full world-space size is snapped to the grid.

Use normal transforms to position and rotate the region. A resized box does not automatically create fresh lighting data. Probe bounds changes require a bake; fog density and bounds changes update the fog itself live.

Editor visualization is not rendered fog or lightingNote

Show Fill, Fill Color, probe marker size, and priority labels help you edit volumes. They do not change the rendered density or lighting strength.

Which action updates which object?

Object	Action after changing captured inputs
Probe Volume	Bake Lighting, then save the level/build data
Box Capture	Bake Reflections, then save the level/build data
Fog Volume	Edits update the fog; rebake only when the probe lighting it samples has changed

For a sequence that combines these objects, see Workflows.