# Author scenes, models and playtests with AI [Back to AI agents & app data](https://rustic-game-engine.pages.dev/markdown/guides/ai-agents.md). The `rustic-workspace` plugin can edit the running editor directly, including unsaved objects, scene selection and script attachments. Its playtest tools start the real runtime, return actual rendered images and send game keyboard input. Inspector clicking and desktop keyboard automation are unnecessary for these operations. ## Setup and guidance 1. Install the updated engine, open the game in its writable editor and reload your agent's Rustic MCP connection. The backend and editor must run on the same computer and OS account. 2. Call `workspace_info` with `{"project_root":"C:/Games/MyGame"}` (use your actual absolute game path). Selection persists for that MCP connection. 3. Read `AGENTS.md` through `read_agent_file`, then call `authoring_guide` with `{}`. The guide supplies current game design, game UI, modeling, scene, script scope and playtest workflows. It remains available when existing customized skill files have been preserved during an upgrade. 4. Call `editor_status` with `{}` to inspect the active scene, full object properties, script lists, recent console messages and play state. The editor publishes a token-protected loopback endpoint in its project-specific app data. Commands execute on the editor thread with the existing project lock, validation and scene undo history. The read-only second editor does not publish an endpoint. File tools remain usable without the editor; live tools report an error when the selected project has no writable editor open. ## Build the scene before pressing Play The guide tells agents to model finished visible assets and author the complete initial scene before playtesting. Built-in primitives are suitable for deliberate blockouts, collision helpers or an explicitly chosen primitive style. Initial scenery must be visible in the editor, with models, camera, lighting, collision flags and script links persisted. Runtime spawning remains appropriate for actual gameplay and explicitly requested procedural content. Use `scene_list` to inspect all scenes, including nested folders. Scene-management paths are relative to the project's configured **scenes folder**: | Tool | Example arguments | Result | | --- | --- | --- | | `scene_create` | `{"path":"levels/forest.scene","name":"Forest"}` | Saves an empty scene; refuses overwrite; keeps the current scene active. | | `scene_switch` | `{"path":"levels/forest.scene"}` | Saves current edits and opens Forest in the editor. | | `scene_set_start` | `{"path":"levels/forest.scene"}` | Sets the launch scene without changing the active editor scene. | | `scene_save` | `{}` | Saves all active authored scene data. | Stop play and resolve any runtime-change review before editing or switching. Call `editor_status` again after switching to get that scene's object IDs. `scene_summary` reads the saved file; `editor_status` reads the live document. `object_create` accepts `name` and `kind`: `folder`, `empty`, `camera`, `light`, or `blockout`, with optional `parent`. Use its returned `entity_id` with `object_update`, for example: ```json { "entity_id": "", "properties": { "name": "Player spawn", "translation": [0, 1, 0], "rotation": [0, 0, 0, 1], "scale": [1, 1, 1], "part_attributes": {"anchored": true, "can_collide": false} } } ``` Translation and scale are local xyz vectors; rotation is an xyzw quaternion. Supported properties are `name`, `parent` (object ID or null), `translation`, `rotation`, `scale`, `part_attributes`, `camera`, `light` and `scripts`. Part attributes merge supplied fields; camera, light and scripts replace the whole component value. Read their exact JSON structure from `editor_status`. A null camera/light removes it. Invalid batches fail without partial object edits. `editor_undo` and `editor_redo` handle object edits. Save with `scene_save`. ## Organize folders and object subtrees Read `scene_explorer_guide` for the bundled hierarchy organization skill. `object_create` with `kind:"folder"` creates actual scene explorer folders; `object_duplicate` copies an object/folder and all descendants with fresh IDs; `object_delete` removes the selected subtree with undo. Use `object_update` to rename or reparent. See [Organize the scene explorer](https://rustic-game-engine.pages.dev/markdown/guides/ai-agents/organize-scene-explorer.md) for copyable examples, parent/transform behavior, recursive deletion and saving. ## Model, preview, then place Agents should prefer Blender when installed, exporting a supported model such as OBJ or GLB. Python/Blender generators, image generators, virtual environments, intermediate images and temporary tools belong **outside the game directory**. Copy only finished assets into the project. Existing user-owned tools are not automatically removed. Without Blender, the plugin can execute an agent-only Lua mesh recipe during authoring. This is separate from gameplay scripting and is not available as a runtime modeling API. A recipe returns xyz vertices and one-based triangle indices. This minimal example demonstrates the format: ```lua return { vertices = {{-1,0,0}, {1,0,0}, {0,1,0}}, triangles = {{1,2,3}} } ``` Before placing a model, call `model_preview` with either a project-relative asset `path` or recipe `source`. The following previews an exported asset: ```json { "path": "assets/models/tree.obj", "yaw_degrees": 45, "pitch_degrees": 20, "distance": 5 } ``` The PNG is rendered from the supplied angle, looking at the geometry's bounds center. `distance` controls zoom by changing camera distance from that center; optional `center:[x,y,z]` changes the target. Defaults frame the model. Request several angles and close-ups, revise the model, then preview again. Preview does not place objects or create an asset sidecar. Call `model_create` with `{"path":"assets/models/tree.obj","name":"Tree"}` to import and place an existing model. To generate and place an OBJ, add `source` containing the recipe and choose a new `.obj` path. The result includes the model asset ID and entity ID. It becomes an ordinary mesh object with scene undo; save with `scene_save`. Undo removes the placement and leaves the reusable asset. Recipes expose math, string and table operations, without OS, filesystem, debug or package APIs. Limits are 256 KiB source, 32 MiB Lua memory, two million instructions, 50,000 vertices and 100,000 triangles. Indices and finite coordinates are validated; coordinates must be within +/-100,000. The recipe format currently covers mesh positions/triangles; use Blender/imported models for UVs, authored normals, multiple materials, skins and animation. ## Choose script scope explicitly Write source into the game using `write_file`, then call `script_attach`. Paths here are relative to the **project root**. The tool registers its persistent script ID and attaches it; no hand-authored registry IDs are needed. | Scope | Arguments | Lifetime and persistence | | --- | --- | --- | | Global | `{"path":"scripts/session.lua","scope":"global","execution_order":0,"enabled":true}` | Game/session services across scene switches; saves `settings.json` immediately. | | Scene | `{"path":"scripts/forest.lua","scope":"scene"}` | Scene startup/lifecycle; saved in the active scene with `scene_save`. | | Object | `{"path":"scripts/player.lua","scope":"object","entity_id":"