Entities & Components

A Lumina world is a flat set of entities. An entity is just an id, it holds no data of its own. Everything about it, its position, its mesh, its behavior, lives in components attached to it. There is no “game object” base class; you compose an entity from the components it needs.

Entities

Create an entity from the Scene Outliner (the + button) or by right-clicking in the viewport. You can:

• Create an empty entity,
• Create one with a single component already on it,
• Create a primitive (cube, sphere, and so on), which is an entity with a mesh,
• Drag an asset (mesh or prefab) from the Content Browser into the scene.

Every entity is created with two components you do not manage by hand:

• Transform, its position, rotation, and scale.
• Name, the label shown in the Outliner (rename from the right-click menu).

Transform and hierarchy

The Transform’s Location, Rotation, and Scale are edited in the Details panel or with the viewport gizmo. These values are local, relative to the entity’s parent (or to the world if it has no parent). Lumina is left-handed and Y-up, in meters, see Worlds & Coordinates.

To parent one entity to another, drag its row onto another row in the Outliner. A child’s transform is then relative to its parent, so moving the parent moves the child.

Components

Select an entity, then click the + button in the Details panel header to add a component. Components are grouped by category and searchable. Once added, a component’s properties appear in Details, generated from reflection, and you edit them there. Property metadata drives the widgets: color pickers, value ranges and units, asset pickers, and an entity-reference picker for fields that point at another entity.

Common components

You will not need most of these at first. Browse the full list in the Add Component menu.

Rendering

Component	Does
Static Mesh	Renders a static mesh asset.
Skeletal Mesh	Renders and animates a rigged mesh.
Text	Draws a world-space text string.
Billboard	A camera-facing textured quad.
Decal	Projects a material onto surfaces.
Post Process	A volume that blends post-process settings.

Lights & environment

Component	Does
Directional / Point / Spot Light	The three light types.
Sky Light	Ambient and image-based fill light.
Environment	Sky background and image-based lighting.
Exponential Height Fog	Height fog and volumetric light shafts.

Camera

Component	Does
Camera	A camera with field of view and post-process settings.
Camera Follow	Eases a camera toward and faces a target.
Spring Arm	A third-person camera boom with collision.

Physics

Component	Does
Rigid Body	Makes the entity a physics body.
Box / Sphere / Capsule / Cylinder Collider	A collision shape.
Mesh Collider	Collision from mesh geometry.

Gameplay

Component	Does
Script	Attaches a Luau script.
Input	Per-entity gameplay input (see Scripting).
Audio Source / Listener	A positional sound, and the listener.
Rigid Body, characters, AI, particles	Movement, navigation, effects, and more.

Custom components without C++

You can define a brand-new component type from the editor. Create an Entity Component Type asset, open it, and add typed fields (bool, number, vector, string, asset reference, enum, and so on). The new type then shows up in the Add Component menu under the Data category and works like any built-in component, editable in Details and readable from scripts.

Prefabs

A prefab is a saved entity, with its children, that you can stamp into a world.

• Create one by selecting entities, right-clicking, and choosing Create Prefab from Selected. Children are captured automatically.
• Place one by dragging the prefab asset from the Content Browser into the viewport or onto an Outliner row.

Placed instances re-sync when you save the prefab, so editing the asset updates every instance, while each instance keeps its own placement. To turn an instance back into plain entities, right-click it and choose Detach from Prefab.