Spawn & arrange a scene

What you’ll build: a lit scene with three named cubes arranged in a triangle, saved to your level. This is your first interactive loop with ClaudeUnreal — drive the editor with plain English and verify each change with a follow-up tool call.

Time: ~20 minutes · Prerequisites: ClaudeUnreal installed, editor running, an empty level open.

Before you start

Verify the bridge is live:

ping

Expected: a JSON success payload that includes the editor version and the name of the current level.

Step 1 — Spawn the first cube

Try this prompt:

Spawn a cube at the world origin and name it CenterCube.

What Claude does

spawn_actor takes a fixed enum of actor types (StaticMeshActor, DirectionalLight, PointLight, …) — “Cube” isn’t a type of its own, it’s a static mesh asset. So Claude does two calls:

1. spawn_actor with type=StaticMeshActor and name=CenterCube to create an empty mesh actor.
2. set_actor_component_property on CenterCube’s StaticMeshComponent0 to set StaticMesh = /Engine/BasicShapes/Cube.Cube.

The actor appears in the Outliner immediately.

Verify

find_actors_by_name CenterCube

Expected: one entry for CenterCube at location=(0, 0, 0) with class StaticMeshActor.

Step 2 — Spawn two more cubes in a triangle

Try this prompt:

Spawn two more cubes — LeftCube at (300, -300, 0) and RightCube at (300, 300, 0).

What Claude does

Repeats the two-call pattern from Step 1 (spawn StaticMeshActor, then assign the cube mesh) for each new cube. Because ClaudeUnreal uses UE’s Z-up left-handed coordinates in centimeters, (300, -300, 0) means 300 cm forward and 300 cm to the left of origin — see Coordinate system.

Verify

find_actors_by_name Cube

Expected: three rows — CenterCube, LeftCube, RightCube.

Step 3 — Add a directional light

Try this prompt:

Add a directional light named TutorialSun, rotated to shine from above at pitch -45 and yaw 30.

What Claude does

Calls spawn_actor with type=DirectionalLight, name=TutorialSun, rotation=(-45, 30, 0). A single call — spawn_actor takes rotation inline, so there’s no separate transform step.

Verify

find_actors_by_name TutorialSun

Expected: one DirectionalLight with a non-identity rotation around (-45, 30, 0).

Step 4 — Rename the cubes with meaningful labels

Try this prompt:

Change the display labels of the three cubes to “Corner A”, “Corner B”, and “Corner C”, in the order CenterCube, LeftCube, RightCube.

What Claude does

Calls set_actor_label three times. The internal FName of each actor stays the same; only the Outliner display label changes. See Actor names vs labels for why this distinction matters.

Verify

find_actors_by_name Corner

Expected: three rows with labels starting with “Corner”.

Step 5 — Save the level

Try this prompt:

Save the current level.

What Claude does

Calls save_level. No parameters needed — it persists whatever level is currently loaded.

What you learned

• spawn_actor — creates actors of a fixed set of built-in types. Supply location and rotation directly on the call.
• set_actor_component_property — the escape hatch for shaping a fresh actor. Setting StaticMeshComponent0.StaticMesh is how “spawn a cube” actually works under the hood.
• UE5 coordinates — Z-up, left-handed, centimeters. See Coordinates if (300, -300, 0) felt arbitrary.
• set_actor_label vs. internal FName — the distinction documented in Actor names vs labels. find_actors_by_name matches both.
• The verify loop — every change Claude makes can be confirmed with a follow-up tool call. Use this pattern throughout every tutorial.

Next: you’re ready for Build a door Blueprint. Or browse the full Scene & Actors reference.

Where cu enters

This tutorial only uses hot-path MCP tools (spawn_actor, set_actor_transform, take_screenshot) — Claude calls them via the typed MCP interface. If you ask Claude to do something more specialized (e.g. “set the cube’s collision profile to BlockAllDynamic”), it’ll go through the discovery flow and execute the long-tail command via cu exec. You’ll see Bash(cu ...) tool calls in your transcript — that’s normal.