Viewing & editing

This documentation page describes how to view and edit reconstructions in the View & Edit tab.

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There are two ways to open a reconstruction in the View & Edit tab:

  • Navigate to the reconstruction in the Managing & Processing tab and double-click it.

  • Go to the View & Edit tab, and click the “Open” button on the top right. Select the reconstruction in the file system. This can be used to open volumetric videos as XRV files, and snapshots (static 3D meshes) as GLB files.

The user interface looks different depending on whether a video or a snapshot is opened: For videos, some additional elements are displayed to control video playback.

The sections below discuss the user interface in the side bar on the right.

File

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If no video or snapshot file is open, then this section allows to open a file.

If a file is open, then this section shows basic details about the file, enables to edit its name (if the file is a reconstruction for a recording in a workspace), locate the file in a file manager, and close the file.

Playback

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This section is only displayed for videos, giving information on and allowing to control video playback.

On the top, information about the video frames and the video’s time range is displayed.

Notice that the timestamps are in Unix Time. This is why the start timestamps are different from zero; they give the absolute date and time at which recording started.

The last line of information displays whether the video includes audio.

Below, there are several input fields which both show information about the playback and can be edited to control it:

  • Current frame: The zero-based index of the currently played back frame. Editing this number will set the playback to the start of the entered frame.

  • Sub-frame playback position: The current sub-frame playback position in the range from 0 to 1: A value of 0 means that playback is at the start of the current frame. A value of 1 means that playback is at the end of the current frame.

  • Current timestamp [s]: The current playback timestamp of the video in seconds. Notice that the start timestamp of a video is usually not zero. See the value given in the “Start timestamp” line above.

  • Loop mode: Whether to stop playback when the end of the video is reached (single-shot mode), or to restart the video from the beginning in this case (loop mode).

  • Playback speed factor: A factor on the video playback speed. For example: A playback speed of 0.5 plays the video at half speed. A playback speed of 1 plays the video at original speed. A playback speed of 2 plays the video at double speed. If any other playback speed than 1 is configured, then the audio (if any) will be muted.

Cutting

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This section allows to cut and concatenate videos. It is always visible because the “Concatenate video files …” button works on external files. However, the cutting function is only applicable when a video is open.

To cut the video file that is open, navigate to the timestamps where you would like to start and stop the cut, then click the “Set cut start” and “Set cut end” buttons, respectively. Notice that the start of a cut can only be set on a keyframe. If the “Set cut start” button is clicked and the current frame is not a keyframe, then a message box will tell you the frame numbers of the previous and of the next keyframe such that you can go to one of them. Finally, click “Perform cut …” and choose the path to write the resulting file to.

Note

If you would like to start a video on a non-keyframe, please cut the video starting from its preceding keyframe instead, and when starting playback, immediately seek the video to the frame that you would actually like to start playback on.

To concatenate two video files, click the “Concatenate video files …” button. This opens a window in which you can choose the two input files and where to write the resulting concatenated video file.

Export

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This section is only shown when a video file is open.

The buttons on the top provide help with deploying video files to game engines or the web.

Below, the current frame or all frames of the opened video may be exported as individual 3D mesh files in the following formats:

  • GLB (Binary GLTF 2.0, using the KHR_materials_unlit extension)

  • PLY (Binary version, with a separate texture in PNG format)

  • OBJ (With a separate texture in PNG format)

Notice that only the GLB format with its KHR_materials_unlit extension is able to store not only the geometry, but also the appearance settings to correctly display the meshes. The PLY and OBJ formats may lead to unwanted artificial lighting on the meshes if the files are opened in external applications. The OBJ format cannot store the alpha values of partially transparent meshes.

Note

As a technical detail for video export as a mesh sequence, notice that a single frame in an XRV video file covers not only a point in time, but a small time range. Exported mesh files are however static. Because of that, exporting a video consisting of a single XRV frame would export two mesh files, one for the start of the XRV frame, and one for its end. In general, exporting all frames of an XRV video will export one more mesh file than the number of frames in the video.

The bottom button in the export section allows to locate a video’s audio file in WAV format. This button is only active if the video contains an audio track.