Driving Actors and the World
The Actors/World toolsets let the agent populate and edit your level: spawn actors, move and rotate them, attach components, query what exists, and clean up. This is usually the first thing people try, because it gives immediate, visible results in the viewport.
What the agent can do
- Spawn actors from a class or asset path (static meshes, lights, blueprints, empty actors) at a given location/rotation/scale.
- Transform actors — set or offset location, rotation, and scale; attach one actor to another.
- Select and query — list actors in the level, filter by class or name, read back an actor's transform and components.
- Edit components — add components to an actor and set their properties.
- Delete actors you no longer need.
Because these are reflected from the engine, the exact tool names follow the
Verb+Noun pattern (for example a spawn tool and a transform tool). Ask the
agent or call describe_toolset to see the precise names and parameters for your
engine version.
Typical workflows
Block out a scene
Just describe it. For example:
"Spawn a floor plane at the origin, then place five cube static meshes in a row 200 units apart, 100 units above the floor."
The agent will discover the spawn and transform tools, spawn the plane, then loop the cubes into position. Everything appears live in the viewport.
Arrange and parent
"Group those cubes under a new empty actor called
CubeRowand rotate the whole group 45 degrees around Z."
The agent spawns an empty actor, attaches the cubes to it, then rotates the parent — the children follow.
Inspect before acting
When a task depends on the current state, the agent reads first:
"List every PointLight in the level and tell me which ones are brighter than 5000 lumens."
It queries actors of that class, reads each light's intensity, and reports back — no changes made.
Tips
- Use full content paths. Spawning from an asset wants a path like
/Game/Meshes/SM_Cubeor/Engine/BasicShapes/Cube. The agent can call the Asset toolset'sFindAssetsfirst if it does not know the exact path. - Coordinates are Unreal units (cm). "Two meters up" is
+200on Z. - Save when you are happy. Spawning actors marks the level dirty but does not
save it. Use the Level toolset's
SaveCurrentLevel(or ask the agent to save) to persist the result. - In a Multi-User session, saves are sandboxed. If you are collaborating in a Concert session, save reusable changes from a non-session editor — see the Multi-User guide and the levels notes for the sandbox gotcha.
Discover the actual tool schema
Use list_toolsets, then describe_toolset with the fully qualified name returned by that catalog. Dispatch through call_tool using toolset_name, tool_name and arguments; the tools reference shows the complete envelope.
World operations need a suitable loaded world and object context. With the GUI closed, verify returned transforms and saved map state; use an interactive editor for viewport or PIE verification. A successful spawn does not prove its visual placement or disk persistence.