The Timeline Panel shows what has happened in the simulation, and when. Events sit under the object they belong to, each on its own row. Markers along that row are the times the event has fired, drawn against a shared time axis.
In the default layout this panel shares a section with the Console Panel. The bar at the top of the panel is the playback header. Play, pause, and speed also appear in the Toolbar Panel. A first-run walkthrough of those controls is in Running a Simulation.
Using the Header
The header, from left to right, is the current UTC time, database recording, playback, speed, and duration.
- Date and Time: The current UTC simulation time, split into a date and a clock. This is the scenario epoch plus how far the run has got, so it moves as you play or scrub.
- Database Recording: The red circle. When it is on, Studio writes simulation history as the run proceeds, which is what scrubbing, plots, and the saved playhead read from. When it is off, new history is not recorded. Turning it off mid-run does not erase what was already written.
- Go to Start: Jumps the playhead to the beginning of the recorded run. This is not a reset: the simulation stays in its current play or pause state, and the initial conditions are not restored.
- Slow Down: Steps the speed multiplier down.
- Play / Pause: Starts or holds the simulation. The same control is in the Toolbar Panel. CTRL+P also plays or pauses.
- Speed Up: Steps the speed multiplier up.
- Go to End: Jumps the playhead to the latest time that has been recorded.
- Simulation Speed: The multiplier relative to real time.
1is real time. Open the control to pick a value, or use slow down and speed up. The default is1. - Simulation Duration: How long the run is configured to last, shown as days, hours, minutes, and seconds.
WARNING
If the speed number is red, Studio cannot reach that multiplier. Lower the speed, or simplify the scenario, until the number returns to the normal color.
Reset, which restores the initial conditions, is in the Toolbar Panel. CTRL+R also resets. See Running a Simulation.
Reading the Lanes
The tree is two levels deep. A group row is an object that owns events, usually a spacecraft or a ground station. Event rows sit under that group. Select the arrow on a group to open or close it. Groups start open.
Events that do not belong to an object in the tree, such as a Space Range region, sit under a group named Other. That group is always first, so its place does not move as objects are added.
Each row is one strip across the panel: the name on the left, the lane on the right. The two columns stay lined up, and the time axis above the lanes starts at the same place the lanes do.
Reading Time
The axis above the lanes is the window onto the run, not the whole history at once. Left alone, that window fits the run and grows as the run does.
Two playheads sit on the lanes:
- The current-time playhead is where the simulation is now. The label next to it is that time as days, hours, minutes, and seconds from the start of the run. The header date and clock are the same instant in UTC.
- The saved playhead is how far the database has been written. That is as far back or forward as a scrub can reach. It is hidden until something has been recorded.
A mark, or a playhead, that falls outside the window is hidden. It is not pinned to the edge it went past, so nothing claims to have happened where it did not.
Scrubbing the Run
Drag on the lanes or the axis to move the simulation to a time that has already been recorded. The drag reaches only as far as the saved playhead. There is nothing to show before the start of the run, and nothing to load past what has been written.
A scrub that actually moves the run will pause a playing simulation, so the moment you dragged to is not overwritten by the next tick. A press ahead of the saved playhead, or a drag when nothing has been recorded yet, does nothing and leaves a running simulation running.
Scrubbing needs a recorded database. If database recording was never on, there is no history to load. Turning recording off mid-run does not erase what was already written; you can still scrub through that earlier stretch.
Clicking a marker selects that event. It does not scrub. The click stops on the mark so the run stays where it is.
NOTE
Timeline scrubbing is only available when the simulation has written a database. See Running a Simulation for playback, and Save Files for what is stored in a project.
Zooming and Panning
Over the lanes, the mouse wheel zooms the view around the time under the cursor. The view will not zoom in closer than about one minute, and it will not zoom out past the whole run.
Over the label column, the wheel scrolls the list of groups and events.
Right-click or middle-click drag on the lanes slides the view along the run. A short click that does not move is not a pan; over the label column, a right click opens the row menu instead.
Once you zoom or pan, the view stays where you put it and no longer follows the run. Zoom back out until the window covers the whole run again, and the view starts following the simulation once more.
Selecting Events
Select an event row to inspect that event. Studio also selects the object that owns it, so the Properties Panel and Outliner Panel describe the same spacecraft or ground station you are looking at. Select a group row to select that object alone.
The rest of the UI follows a single selected event. There is no multi-select on the timeline.
Searching the Timeline
Type in the search field to filter the tree. Matching is not case-sensitive. A matching event keeps the group it sits under, so a result is never shown without saying what it belongs to. A group whose own name matches keeps all of its events.
While a search is running, groups that hold a match are opened. Clearing the search restores the open and closed state you had before.
Once the search is four characters or longer, it also matches the class of the object a group stands for. Typing spacecraft will list every spacecraft’s events, regardless of what the spacecraft are named.
Adding and Editing Events
Some events are created by the simulation, such as eclipse and ground-station access. Those rows cannot be renamed, duplicated, or deleted.
Custom events can be added while the simulation is reset. Select the object that should own the event, then select Add Event, or use the add control on that object’s group row. The new event is named New Event and lands selected, scrolled into view, and ready to be renamed. If nothing is selected, the event goes under Other. The add control greys out once the simulation has started.
Right-click an event name (not its lane) for Rename, Duplicate, and Delete. Those options are offered only on custom events, and only while the simulation is reset. Group rows have no menu; change the object itself from the Outliner Panel.
Rename: Choose Rename, or press F2. Type the name and press ENTER, or click away, to apply it. ESC cancels.
Duplicate: Choose Duplicate. The copy keeps the original’s triggers and actions, but none of its identity and none of its firing history. It lands selected, ready to rename.
Delete: Choose Delete, or the delete control on the row. Built-in events cannot be removed.
Custom event rows also have a control that does one of two things, depending on the run. While the simulation is reset it reads Edit Event and opens the event’s editor, the same window a double-click on the row opens. Once the simulation is running or paused it reads Execute and fires the event at the current simulation time, as a user input. There is no time to record a firing against while the run is reset, and nothing worth editing partway through a run.
The editor closes as soon as you click elsewhere in the panel, select something else, or start playback. Double-clicking a different event moves the editor onto that event.
WARNING
Custom events can be added, renamed, duplicated, or deleted only while the simulation is reset. Play, pause, or scrub, and those edits are turned off until you reset.
To configure triggers and actions on an event, use the Events tab in the Properties Panel. A worked example is in Configuring Events.
Editing Events
Any custom event can be edited via the timeline panel by clicking on the Edit button (the pencil icon). This will allow for editing of the triggers and the actions for the events. Events can only be edited while the simulation has stopped or been reset.
A trigger defines when the event will be triggered, such as after a certain amount of simulation time or when a particular property on an object is reached a value. The action defines what happens when the event is triggered, such as invoking a method or updating a property.
Reading Markers
Each mark on a lane is one firing, or one time a timer is going to fire.
- A firing that happened at a single time is drawn as a point.
- A firing that lasted is drawn as a bar stretched across that span.
- A scheduled mark (drawn fainter) is the next time a timer on that event will fire. Once the run passes that time, the scheduled mark is removed and a real firing mark takes its place.
Markers are colored by what triggered them, not by which event they belong to. A timer, a user input, an MQTT message, and a flag therefore look different even when they sit on the same spacecraft.
Hover a mark to read the owner, the event name, the trigger type, and the time (and length, when the firing lasted). Marks that sit outside the current view are hidden rather than stacked on the edge.
Using Keyboard Shortcuts
Click a row first so the panel has keyboard focus. Shortcuts do nothing while you are typing a new name.
| Input | Action |
|---|---|
| UP / DOWN | Move the selection to the previous or next event, skipping group headings |
| F2 | Rename the selected custom event |
| Mouse wheel over the lanes | Zoom the time view |
| Mouse wheel over the names | Scroll the list |
| Right-click or middle-click drag on the lanes | Pan the time view |
| Drag on the lanes or axis | Scrub to a recorded time |