Record Panel: Save and Playback a Session

The Record Panel Button in the OpenSpace Toolbar.

The Record Panel enables the recording of a session. Included are the flightpath, the assets used, and the time settings. Once a session is recorded and saved, you can play it back later using the same panel.

While OpenSpace was designed to be an interactive tool to explore data, there are times when you’ll want to record a session to playback for an audience so you do not have to recreate all the camera moves and scene settings. Or, you may want to render frames from a recording session into a movie. We will discuss how to do these things below.

The Record Panel in OpenSpace.

Record a Session

Recording a session is easy, but you’ll want to do some homework before you hit the Record Button. First, you’ll want to have the data sets configured how you like to see them. If you want trails on or off, if you want certain data sets on or off, etc. Second, you’ll want to adjust the time settings to your liking. Finally, you’ll want to map out your planned flight a bit to have a notion of your planned route and any flight moves.

Once you’re ready, proceed to your starting point. Enter a filename, without an extension, in the Enter recording filename box, the press the Record Button, leaving all other options unchecked.

Once the recording begins, you will see a red indicator on the Toolbar and the Record Panel will disappear.

Portion of the OpenSpace Toolbar showing a recording in progress.

Once you’re finished with your session, press the red Stop Recording Button in the Toolbar.

The resulting file is saved in the user/recordings folder and has an .osrec extension. The file itself is binary, so it is unreadable in a standard text editor.

Advanced

Option: Text File Format

If you check the Text file format option in the Record Panel, the file will be saved in a readable text format. This is less efficient than the default binary format, but allows you to fine-tune the parameters. This is an advanced topic because you can only fine-tune these parameters by writing code yourself to hand-make a flightpath over some period of time. It is virtually impossible to create a sensible flightpath by altering the position and view angles by hand.

With this option checked, the resulting file will have an .osrectxt extension.

An example line from the resulting text file will appear, mostly, as a series of numbers:

camera 35.6259 0.125842 624861769.816 14150159.7269534 1447711.8646562 22214479.4404503 -0.2036835 -0.1934829 -0.7594912 -0.5867287 4.0000052e-07 F Earth

Each field in this line is defined as:

Table with caption

Column	Description	units
1	[camera or script] denotes that this row represents a camera keyframe or script action.
2	Time since OpenSpace launch	seconds
3	Time since the start of the recording session	seconds
4	A time stamp for the simulation time in OpenSpace	J2000 seconds
5	X coordinate of the camera position	meters
6	Y coordinate of the camera position	meters
7	Z coordinate of the camera position	meters
8	X value of the camera’s rotation vector	unitless
9	Y value of the camera’s rotation vector	unitless
10	Z value of the camera’s rotation vector	unitless
11	W value of the camera’s rotation vector	unitless
12	A scale value realted to camera’s zoom (smaller = zoomed out)
13	[T or F] Is the camera following the the rotation of the focus mode (e.g., rotating along with a planet to remain fixed over a position on that planet)	True or False
14	OpenSpace identifier of the camera’s focus node

If you wish to comment out a line, you can use the # character.

Playback a Session

Playing back a previously recorded session will abruptly move you to the starting point of the recoded session, then play the session. The time in OpenSpace will shift to the time settings when the sessions was recorded. Navigation control is disabled during playback.

Choose a file to be played back using the dropdown menu. The files that appear here are located in your user/recordings directory. Choose the desired file, then press the Play Button.

Portion of the OpenSpace Toolbar showing a playback in progress.

Once you play a recording back, the blue Pause and Stop Playback buttons appear in the Toolbar.

Option: Loop Playback

When the Loop Playback option is checked, the session will repeat itself, going directly to the beginning of the recorded session once it has reached the end. Time will revert back to the beginning of the session as well.

Playback will run continuously until you use the Stop Playback or Pause buttons.

Option: Output Frames

The Output Frames option determines whether screen shots are generated for the recoded session during playback. Once you check this option, you can specify the desired framerate. Pressing Play will then play the session, and take a snapshot at each frame—this will cause the playback to be a bit slower. Outputting frames will create a series of .png image files in the user.screenshots/[timestamp], for example, user/screenshots/2024-10-27-14-30-00 if you began recording frames on 27 October 2024 at 2:30pm.

The resulting images may be imported into a program that can render them into a movie file.