First run

When LunCoSim opens, you are looking at a workbench, not a single fixed editor. The same Twin can be viewed as a running mission, a scene assembly, a graph dashboard, a USD document, or a Modelica model. The first run is about learning where those views are and how to open a working scene.

The window

Area	What it does
Title bar	File, Edit, View, Window, and Help menus; command palette; transport; perspective tabs
Viewport	The live 3D scene, selection, camera, and ground interaction
Side panels	Twin files, Entity tree, Inspector, Environment, Spawn, Telemetry, Ports
Bottom dock	Graphs, timelines, logs, and document tabs
Status bar	Update notices, simulation state, and transient messages

The exact panels depend on the active perspective. View → Reset Layout restores the authored default for the current task.

The View perspective with the First Drive sandbox open. Panels and tabs change when you switch perspectives.

Perspectives

Choose a perspective from the title bar or View → Perspectives:

Perspective	Use it for
◉ View	Operating the live mission in a full-window scene
⚒ Build	Composing the scene from assemblies, entities, and the Twin's files
↗ Analyze	Comparing signals in Graphs, with Telemetry and Ports
✎ Editor	Editing one explicit USD document in an isolated preview
∿ Lunica	Modelica text, diagrams, compilation, and experiments

Switching perspectives preserves the Twin and the simulation. You are changing the layout and the visible tools, not restarting the world.

For a detailed tour of each task and its controls, see Perspectives.

Open the tutorial catalog

The authored lesson catalog is under Scenarios → Tutorials. Tracks include Start Here, LunCoSim, How It Works, Navigation, Sandbox, Rover Driving, and Modelica.

Each entry is a tour, an exercise, or a challenge:

• A tour explains where things are. It advances with Next and Back and does not certify that you performed an action.
• An exercise advances only when the simulation observes the requested result.
• A challenge is a longer open-ended task.

Selecting a lesson loads its authored scene when the lesson needs one, then starts the lesson's Rhai scenario. This is the easiest way to see a working Twin without building one first.

First five minutes

1. Open Scenarios → Tutorials → Start Here → Lunar Rover Lab for the full 30-minute classroom exercise, or Scenarios → Tutorials → Sandbox → First Drive for a five-minute rover drive.
2. Wait for the scene and the lesson card to settle. The viewport shows the practice yard; the card explains the current step.
3. Click Take control. Selection is not control: you must claim the rover before your input reaches it.
4. Drive with the displayed bindings. The defaults are W/S for forward and reverse, A/D to steer, and Space to brake. The lesson uses input_hint(...), so it always shows the bindings currently configured on your machine.
5. Follow the on-screen objective. When you reach the marker, stop inside it. The lesson checks the simulation state, not a timer.

If the rover rolls over, use Right rover. If you lose the view, use Return camera. Both actions preserve lesson progress.

The empty viewport

A new session may start with an empty persistent world shell. That is expected: the sandbox is an explicit scene or lesson, not an implicit startup default. Use the viewport actions to open the featured lesson, choose a recent Twin, or open a scene from the Twin browser.

A Twin without default_scene opens as a file browser rather than mounting a world. That is also expected; the manifest has not selected a stage. See Twins and twin.toml.

If you get stuck

Symptom	Check
The vehicle ignores your input	Click Take control first; selection is not control.
The viewport is empty	Open a scene or lesson; a Twin with no default_scene does not mount a world.
An asset is missing	LunCoSim asks before downloading declared external assets. See Assets.toml.
The app will not start on a port	Choose another free --api port.
A lesson card does not advance	Read the current objective; an exercise waits for the simulation, not for a click.

Next steps

Continue with First mission for the suggested learning path, or read How it fits together to understand what the lesson is doing behind the scenes. For the complete keyboard and camera reference, see Controls.