The timeline allows you to navigate between frames and provides additional controls depending on the current working mode.

With The Timeline You Can:

Switch to the specific frame of a sequence

Click on the specific frame on the timeline or enter its number in the Current field.

Set Active Range

The Active Range controls the range of frames that are displayed on the timeline. You can only play back the sequence and navigate between the frames within the Active Range.

To change the Active Range, you can adjust the first and the last frame number in the Active Range field.

The active range does not always have to fit within the actual size of the sequence. If you switch to a nonexistent frame, the frame will be marked red on the timeline.

Set Selected Range

The Selected Range is used by some operations in R3DS Track to specify which frames should be affected.

To change the Selected Range, drag the gray handles at the beginning and at the end of the timeline. You can also enter the first and the last frame numbers in the Selected Range fields.


The timeline only becomes visible after loading a sequence of frames.

Caching Frames

R3DS Track caches a frame when you display it for the first time. Cached frames are displayed in blue on the timeline.

You can adjust the cache capacity if needed.

If R3DS Track can’t read a frame, it marks it in red on the Timeline. This can happen for several reasons.


Timeline colors can be set in Preferences > Timeline (See: Color Palette).

Caching Errors

If after switching to a frame the label above it turns red, then it means it was currently impossible to cache it. Frequent reasons and possible solutions:

  • File does not exist - no frame file was found in this location (the path is indicated in the error pop-up message above the timeline). Specify the correct path to the frame using the field Sequence in Load mode. If the frame cannot be loaded for the training frame from Detect mode, use Change Path or Change Dir.

  • The file is too big - the file cannot be loaded into the cache at its current size. Increase the cache size using the Cache Mem (GB) field in Load mode.

  • The File is corrupted - the file cannot be opened as an image. Use a different file.